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© 2007 Les Mills International Limited 1
BODYPUMP Research Report
© 2007 Les Mills International Limited 2
Table Of Contents
EXECUTIVE SUMMARY Les Mills International (2006) ……………………………………………………………………………………….
THE AEROBIC DEMAND AND ENERGY EXPENDITURE DURING BODYPUMP™ Pfitzinger, P and Lythe, J UniSports Centre for Sport Performance, University of Auckland (1999)
Introduction ....................................................................................................................................................8
Fat Weight Loss.............................................................................................................................................8
Exercise Post-exercise Oxygen Consumption (EPOC) ................................................................................9
Calculation of Caloric Expenditure Using Gas Analysis..............................................................................11
METHODS...................................................................................................................................................12
Subjects .......................................................................................................................................................12
Procedures ..................................................................................................................................................12
BODYPUMP™ ............................................................................................................................................13
Cycling .........................................................................................................................................................13
VO2 Max Test ..............................................................................................................................................13
Results.........................................................................................................................................................13
Discussion ...................................................................................................................................................17
Aerobic Intensity ..........................................................................................................................................18
Energy Expenditure .....................................................................................................................................19
Additional Benefits of BODYPUMP™ .........................................................................................................20
References ..................................................................................................................................................21
AN ATTITUDINAL STUDY ON THE BODYPUMP™ WORKOUT
AC Nielsen (1999)
Objectives ................................................................................................................................................... 23
Methodology ................................................................................................................................................23
Results.........................................................................................................................................................24
Enjoyment of BODYPUMP™ ......................................................................................................................24
Benefits of BODYPUMP™ ..........................................................................................................................24
Injuries Resulting from BODYPUMP™ .......................................................................................................25
Likelihood of Continuing BODYPUMP™ Class...........................................................................................25
Comment on BODYPUMP™.......................................................................................................................25
Other Sporting Activities BODYPUMP™ Members Take Part In................................................................27
Summary Discussion...................................................................................................................................28
© 2007 Les Mills International Limited 3
THE PHYSICAL AND PSYCHOLOGICAL RESPONSE TO 13 WEEKS OF STRUCTURED
GROUP-FITNESS EXERCISE IN UN-TRAINED INDIVIDUALS:
Lythe J, Pfitzinger P and Ho D UniSports Center for Sport Performance, University of Auckland (2000)
Introduction ..................................................................................................................................................29 Methods .......................................................................................................................................................29 Test Descriptions.........................................................................................................................................30 Intervention ..................................................................................................................................................31 Data Analysis...............................................................................................................................................32 Results.........................................................................................................................................................32 Discussion ...................................................................................................................................................47 Body Composition .......................................................................................................................................48 Aerobic Fitness............................................................................................................................................49 Upper Body Strength ...................................................................................................................................49 Upper Body Muscular Endurance ...............................................................................................................50 Lower Body Strength ...................................................................................................................................50 Lower Body Muscular Endurance ...............................................................................................................50 Psychological Well-Being ............................................................................................................................50 Subject Adherence ......................................................................................................................................51 Limitations....................................................................................................................................................51 Conclusion ...................................................................................................................................................51 References ..................................................................................................................................................52 Appendix......................................................................................................................................................53
THE PHYSICAL AND PSYCHOLOGICAL RESPONSE TO 18 WEEKS OF STRUCTURED
GROUP-FITNESS EXERCISE IN UN-TRAINED INDIVIDUALS
Lythe J, Pfitzinger P & Ho D UniSports Center for Sport Performance, University of Auckland (2000)
Introduction
Methods
Results
Discussion
Conclusions
EXCESS POST-EXERCISE OXYGEN CONSUMPTION FOLLOWING BODYPUMP™ Lythe J UniSports Centre for Sport Performance, University of Auckland (2001)
Introduction ..................................................................................................................................................60
EPOC...........................................................................................................................................................61
BODYPUMP™ ............................................................................................................................................63
Methods .......................................................................................................................................................64
Subjects .......................................................................................................................................................64
Body Composition .......................................................................................................................................64
VO2 max.......................................................................................................................................................65
EPOC Session.............................................................................................................................................67
Results.........................................................................................................................................................67
Discussion ...................................................................................................................................................70
© 2007 Les Mills International Limited 4
SUMMARY ..................................................................................................................................................71
REFERENCES ............................................................................................................................................73
© 2007 Les Mills International Limited 5
EXECUTIVE SUMMARY LES MILLS INTERNATIONAL (2006)
BODYPUMP™ is a high-repetition, resistance training, pre-choreographed exercise program
choreographed and developed by the Les Mills BODYPUMP™ team. The potential benefits of
BODYPUMP™, including calorie and fat burning benefits, improved aerobic fitness, muscular strength
gains, improved muscular endurance capabilities and positive psychological benefits, have been
researched[1-5]
by independent research teams contracted by Les Mills International over the period of 1999
to 2001. The BODYPUMP™ team has utilized the information gained from this research to guide further
development and improve the efficacy of the BODYPUMP™ program.
To date the key research findings of the potential benefits gained from undertaking the BODYPUMP™
program are summarized as follows. All data reported can be viewed in detail within the main body of this
report.
Potential benefits of BODYPUMP™ supported by scientific research:
• Calorie Burning Benefit:
� An average of 483.1 (males) and 338.9 (females) calories can be burned during a
BODYPUMP™ session. This equates to 8.4 (males) and 5.9 (females) calories per minute. The
maximum number of calories burned has been shown to be 424 (female), and 603 (male)[1]
.
� An additional 10% of calories (32.3 kcal in males (n=5) experienced in performing
BODYPUMP™; 43.7 kcal in males (n=7) inexperienced in performing BODYPUMP™) have
been shown to be burned after the cessation of a BODYPUMP™ session, due to Excess Post-
Exercise Oxygen Consumption (EPOC)[5]
.
• Fat Burning Benefit:
� 88.6 (males) and 51.5 (females) calories of fat, and 394.4 (males) and 287.4 (females) calories
of carbohydrate, have been consumed during a BODYPUMP™ session. This equates to 18.6%
fat and 81.4% carbohydrate in males and 14.9% fat and 85.1% carbohydrate in females[1]
.
� Significant reductions in skinfold measures (23.7mm, males, n=16) and (33.8 mm, females,
n=24) have been observed over a 13-week BODYPUMP™ training period where no other
training activity or change in diet was undertaken[3]
.
© 2007 Les Mills International Limited 6
� Significant reductions in percent body fat (2.9%, males, n=16) and (2.6%, females, n=24) have
been observed over a 13-week BODYPUMP™ training period where no other training activity or
change in diet was undertaken[3]
.
• Improved Aerobic Fitness:
� During a BODYPUMP™ session the mean oxygen consumption has been shown to be 21.5
ml/kg/min (males) and 19.0 ml/kg/min (females) with an average intensity of 41.6% VO2 max
(males) and 39.8% VO2 max (females) observed. Males spent an average of 11.6 minutes and
3.2 minutes, and females, 8.0 minutes and 0.6 minutes, above 50% VO2 max and 70% VO2
max, respectively, during the same BODYPUMP™ session. The average heart rate during a
BODYPUMP™ session has been shown to reach 138.2 beats per minute (males) and 132.6
beats per minute (females). Males spend an average of 37.4 minutes, and females 40.2 minutes,
above 70% of maximum heart rate during a BODYPUMP™ session[1]
.
� Significant improvements in ‘Beep test’ scores (change of 6.3, males, n=16; change of 4.3,
females, n=24) measuring aerobic endurance, have been observed over a 13-week
BODYPUMP™ training period where no other training activity was undertaken[3]
. The ‘Beep test’
scores (n=11, males) further improved with an additional 5 weeks of BODYPUMP™ training[4]
.
• Muscular strength gains:
� Increases in upper body strength (6.0 kg, males, n=16; 4.7kg, females, n=24) using the 6RM
Bench Press as a measure, and lower body strength (9.4 kg, males, n=16; 20.0 kg, females,
n=24) using the 6RM Leg Press as a measure, have been observed over a 13-week
BODYPUMP™ training period where no other training activity or change in diet was undertaken
[3]. These strength measures (n=11, males) continued to improve with an additional 5 weeks of
BODYPUMP™ training[4]
.
• Improved muscular endurance capabilities:
� Increases in upper body muscle endurance capabilities (4.3 kg, males, n=16; 5.5 kg, females,
n=24) using the 70% 6RM Bench Press as a measure, and lower body muscle endurance
capabilities (9.4 kg, males, n=16; 20.0 kg, females, n=24) using the 70% 6RM Leg Press as a
measure, have been observed over a 13-week BODYPUMP™ training period where no other
training activity or change in diet was undertaken [3]
.
© 2007 Les Mills International Limited 7
• Positive psychological benefits:
� High levels of enjoyment, an improved overall feeling of well-being, improvements in the
performance of other sports and exercise activities, a feeling and sense of improved
coordination, flexibility, muscle strength and tone have been reported (n = 200)[2]
.
� Positive changes in psychological scores have been observed in males (n=16) and females
(n=24) following a 13-week BODYPUMP™ training period where no other training activity or
change in diet was undertaken[3]
.
Future research:
The Les Mills Research and Development team are currently reviewing all relevant past research. Further
research is planned to extend and build on existing research findings in order to continue to improve and
develop the BODYPUMP™ program. Future research will focus on strengthening the methodology and
design of studies by addressing any limitations noted from past research (eg small sample sizes) as well as
extending the number and depth of parameters examined (eg BODYPUMP™ exercise intensities in a large
and diverse population, the acute and long term effects of BODYPUMP™ on hormonal changes, and the
longitudinal effects of the BODYPUMP™ program on body composition such as lean muscle mass.
References
1. Pfitzinger, P. and Lythe, J. (1999). The aerobic demand and energy expenditure during
BODYPUMP™. Auckland, UniSports Centre for Sport Performance, University of Auckland.
2. International Survey Company A.C. Nielson. (1999). An attitudinal study on the BODYPUMP™
workout. Auckland, International Survey Company A.C. Nielson.
3. Lythe, J., Pfitzinger, P & Ho, D. (2000). The physical and psychological response to 13 weeks of
structured group-fitness exercise in untrained individuals. UniSports Centre for Sport Performance,
University of Auckland.
4. Lythe, J., Pfitzinger, P & Ho, D. (2000). The physical and psychological response to 18 weeks of
structured group-fitness exercise in untrained individuals. UniSports Centre for Sport Performance,
University of Auckland.
5. Lythe, J. (2001). Excess Post-Exercise Oxygen Consumption following BODYPUMP™. UniSports
Centre for Sport Performance, University of Auckland.
© 2007 Les Mills International Limited 8
THE AEROBIC DEMAND
AND ENERGY EXPENDITURE DURING BODYPUMP
Pfitzinger P and Lythe, J
UniSports Center for Sports Performance, university of Auckland (1999)
Introduction
Several variables contribute to the effectiveness of an exercise training program in reducing body fat and
improving the various components of fitness, including the frequency, intensity, duration and type of
exercise. BODYPUMP™ is a high-repetition, resistance training, choreographed exercise program.
Although the potential benefits of BODYPUMP™ have not been comprehensively quantified, the training
program may elicit improved muscular endurance, increased aerobic fitness, fat weight loss, and
maintenance of, or increases in, lean body mass. The objective of the present study was to measure the
aerobic demand and caloric expenditure of a standard session of BODYPUMP™.
Fat Weight Loss
The primary goal of any weight-loss program should be to lose fat weight rather than total body weight. To
lose fat, an individual’s energy expenditure must exceed his or her energy intake. The variables that
influence energy expenditure include resting metabolic rate (RMR), the thermic effect of food (TEF), and
the thermic effect of physical activity (TEPA)[9]
. Exercise increases total daily energy expenditure, leading to
loss of fat mass.
The body can be considered as consisting of two compartments: fat-free mass (FFM) and fat mass (FM). A
minimal amount of fat is necessary to maintain hormone levels, metabolic processes and protect vital
organs. Excess fat, however, is associated with a variety of lifestyle-related illnesses and has negative
social connotations. Individuals should strive to lose body fat while maintaining lean body mass. Exercise
increases energy expenditure and the loss of fat mass, while maintaining or increasing FFM.
It takes 7,700 kcal (32,000 kJ) to burn 2.2 pounds (one kilogram) of fat. By increasing total daily
expenditure, exercise can lead to a negative caloric energy balance. Low-intensity exercise as opposed to
high-intensity exercise is prescribed by many practitioners as an effective way to lose fat mass because fat
is the main fuel source for low-intensity exercise. Studies have shown however that although low-intensity
exercise uses predominantly fat as a fuel source, the total amount of energy derived from fat may be
greater during moderate to high-intensity exercise[14]
. In addition, it is the balance between the total calories
used and consumed, not the source of the calories used, that determines whether a person actually loses
© 2007 Les Mills International Limited 9
weight[14]
. For example, as seen in Table 1, one hour of jogging utilizes both more total calories and more
calories from fat than one hour of walking.
Table 1: Caloric and substrate use during exercise bouts
CALORIES FROM FAT EXERCISE
(mode) DISTANCE
(miles) SPEED (mph)
DURATION (mins)
TOTAL CALORIES (kcal)
% kcal
Walk 4 4 60 270 60 160
Jog 4 6 40 450 40 180
Jog 6 6 60 680 40 270
Reproduced from Puhl and Clark (1992)
Exercise influences total daily expenditure through the thermic effect of physical activity (TEPA). The effect
of exercise on resting metabolic rate is still controversial. Exercise may increase resting metabolic rate but
intensity, duration, frequency and subject variability impact the dynamics of RMR[10]
. Some researchers
suggest that there may be as much as an 8% increase in RMR following five weeks of exercise at 60% VO2
max for 45 minutes, five days a week[11]
, while others have suggested that exercise has little or no effect on
RMR.
Exercise Post-exercise Oxygen Consumption (EPOC)
The two components comprising the thermic effect of physical activity (TEPA) are the energy expended
during exercise and excess post-exercise oxygen consumption (EPOC). EPOC has been defined by
Sedlock et al., (1989) as “the energy expenditure during the post-exercise period while the metabolic rate
remains elevated above the pre-exercise level.” The energy expended during the activity itself accounts for
the majority of exercise-related energy expenditure. EPOC, however, may have important implications for
weight control, since it contributes to total daily energy expenditure. For example, if an individual has a net
EPOC of 40 kcal per exercise session, and exercises four times per week for one year, his or her EPOC-
related energy expenditure would total 8,320 kcal, representing over one kilogram of fat loss. EPOC occurs
because of the time required to correct the disturbance in homeostasis caused by exercise [15]
. Factors
such as increased catecholamine concentrations[1]
, and elevated core temperature requires time to return
to pre-exercise levels.
Both the intensity and the duration of exercise determine the magnitude of EPOC. Table 2 presents the
results of a variety of studies investigating the magnitude of EPOC with various types, intensities, and
durations of exercise. Although the magnitude of EPOC varied widely between these studies, they provide
insight into the order of magnitude expected following an hour of exercise.
© 2007 Les Mills International Limited 10
Table 2: Summary of EPOC studies
STUDY n STUDY DESIGN No. CALORIES from
EPOC, % TOTAL CONCLUSIONS
Sedlock et al., 1989
[16] 10
Cycling HS = 300 kcal @ 74% VO2 max
LS = 300 kcal @ 51% VO2 max
LL = 600 kcal @ 50% VO2 max
HS = 29.4, 9.7%
LS = 14.3, 4.7%
LL = 12.1, 1.1%
Intensity of exercise (>50%) affects magnitude and duration of EPOC. Duration of exercise only affects duration of EPOC
Quinn et al., 1994
[15] 8
Walking @ 70% VO2
max for 20, 40 and 60 minutes
20 mins EPOC = 46.3, 24.5%
40 mins EPOC = 59.6, 16.5%
60 mins EPOC = 89.2, 16.2%
Exercise duration significantly affects EPOC
Chad and Wenger, 1995
[1]
6 Cycling for 15 minutes @ 50% and 70% VO2 max
15 mins EPOC (50%) = 95, 50%
15 mins EPOC (70%) = 190, 46%
30 mins EPOC (50%) = 190, 51%
30 mins EPOC (70%) = 95, 24%
Duration of exercise has a greater effect on EPOC than intensity
Dawson et al., 1996
[2] 8
Cycling HI = 30 mins at 65% VO2 max
MI = equal energy cost as HI @ 55% VO2 max
LI = equal energy cost as HI @ 45% VO2 max
HI = 32.6, 6.3%
MI = 27.8, 4.8%
LI = 25.6, 4.6%
The magnitude of EPOC was greater after high-intensity exercise compared to isocaloric moderate or low- intensity exercise
Olds and Abernethy, 1993
[12]
7
60 minutes of resistance training (75% 1RM and 60% 1RM)
EPOC ranged from 4 to 135 kcal
Large inter-individual variation, no significant differences between the two resistance training protocols
© 2007 Les Mills International Limited 11
Elliot et al., 1992
[3] 9
40 minutes of cycling, circuit training, and heavy-resistance lifting
Circuit EPOC = 49±20, 13.2%
Cycling EPOC = 32±16, 7.4%
Heavy lifting = 51±31, 20.6%
Heavy-resistance training and circuit training result in an EPOC comparable to aerobic exercise
HS = High speed; LS = Low speed; LL = Low level; LI = Low intensity; MI = Moderate intensity;
HI = High intensity
Calculation of Caloric Expenditure Using Gas Analysis
Caloric expenditure during exercise can be calculated by measuring the volume of inspired or expired air
and the concentrations of oxygen (O2) and carbon dioxide (CO2) in expired air. The respiratory exchange
ratio (RER) is the ratio of the volume of CO2 produced to O2 consumed by the body per minute [5]
. The
respiratory exchange ration ranges from 0.70 if fat provides 100% of the energy utilized to 1.00 if
carbohydrate provides 100% of energy for exercise[13]
. During low intensity, mostly fat oxidation is
occurring; therefore, the RER is in the lower end of the range. A subject that exercises at a higher intensity
uses mostly CHO as energy, which is associated with a high RER value. It is generally assumed that
protein contributes less than 10% of the energy utilized during exercise. Due to the modest contribution of
protein to energy expenditure and the technical difficulty in measuring amino acid combustion, a non-
protein respiratory exchange ratio is used to determine the energy equivalent.
Lactate accumulates in the blood and muscles during high-intensity exercise. Lactate is subsequently
either oxidized or converted to glycogen. If lactate returns to resting levels before the cessation of exercise,
then gas analysis accurately reflects caloric expenditure because glucose is converted to lactate and
eventually oxidized[4]
. If lactate levels remain elevated upon the cessation of exercise, however, the
measurement of caloric expenditure using gas analysis may underestimate the total energy expended.
Studies have shown that the rate of fat oxidation is highest during moderate activity (approximately 65%
VO2 max)[6]
. There are several reasons why there is a shift from fat oxidation to CHO oxidation as exercise
intensity increases, including the presence of intramuscular triglycerides, circulating catecholamines, lower
adenosine triphosphate (ATP) production from fat per unit time, and the gradient of fatty acids between
blood and muscle. As exercise intensity increases from low to moderate, it is likely that the total fat
oxidation increases from because intramuscular triglycerides provide additional fatty acids[8]
. During high-
intensity exercise the rate of fat oxidation falls because of an increase in circulating catecholamines that
stimulate glycogen breakdown and the rate of glycolysis, and suppress fat metabolism [6]
. The shift from fat
to CHO as exercise intensity increases is necessary for high-intensity exercise to occur because ATP is
produced at a faster rate when CHO is metabolized compared to fat[6]
. The body needs approximately 15%
more oxygen for the production of a given quantity of ATP from fat, compared to carbohydrate. In addition,
© 2007 Les Mills International Limited 12
as exercise intensity increases there are limitations in the movement of fatty acids from blood to
mitochondria, which limits the amount of fat oxidation during high-intensity exercise[6]
.
METHODS
Subjects
The subjects in this investigation were 10 adults who regularly participate in gym-based fitness activities.
Table 3 presents the subjects’ descriptive characteristics. At the time of the study, the subjects completed
an average of five fitness sessions per week. All subjects were familiar with ‘BODYPUMP™’ aerobics,
having participated at least once per week for an average of four years. Exercise histories were obtained
from the subjects prior to the first testing session. All subjects completed Informed Consent documents in
accordance with University of Auckland policies.
Table 3: Subject characteristics
Mean (SD)
Age (years)
Mass (kg)
Height (cm)
VO2 Max (ml/kg/min)
Max heart rate (beats/min)
All subjects 32.7 (4.2) 71.1 (13.3) 171.4 (6.5) 50.1 (8.9) 182 (9)
Males only 31.1 (3.5) 79.5 (12.0) 175.0 (6.0) 52.6 (11.6) 186 (10)
Females only 34.3 (4.5) 62.6 (8.6) 167.8 (5.3) 47.6 (5.1) 179 (6)
Procedures
Each subject reported to the laboratory three times, including a BODYPUMP™ session, a 60-minute
session of cycling, and a VO2 max test. The cycling session was included to provide a comparison between
BODYPUMP™ and a traditional gym-based mode of exercise known to be effective in consuming calories.
Body mass was assessed to the closest 0.1 kilogram, and height was measured to the nearest 0.5
centimeter.
Metabolic data were collected using indirect calorimetry. The subjects breathed through a Hans Rudolph
mouthpiece connected to a Hans Rudolph, two-way, non-rebreathing valve (Kansas City, MO), and wore a
nose clip. Inspired air was measured using a K520 flow transducer (KL Engineering, Sylmar, CA). Expired
gases were sampled every 60 seconds from a 5-liter mixing chamber and analyzed using Ametek S-3 A1
oxygen and CD-3A carbon dioxide (CO2) analyzers. Prior to each test, the oxygen and CO2 analyzers were
calibrated using a gas mixture of known concentration. The analyzers and flow transducer were interfaced
through an 8bit A/D converter to an IBM-compatible computer. Ventilation, oxygen consumption, CO2
production, and respiratory exchange ratio were calculated and displayed using Ametek OCM-2 Oxygen
Uptake System Software. Heart rate was monitored using a telemetric system (Vantage XL, Polar Electro,
Finland).
© 2007 Les Mills International Limited 13
For the BODYPUMP™ and cycling sessions, caloric consumption per minute and the percentage
contribution from fat and carbohydrate were calculated from the oxygen consumption and respiratory
exchange ratio (RER) values obtained during the exercise tests, using the table of non-protein respiratory
quotients provided by Peronnet and Massicotte (1991)[13]
BODYPUMP™
Each subject performed a BODYPUMP™ aerobics class under the individual instruction of a Les Mills
employee. The same instructor and class program was used for all subjects. The subject selected the
weights used for each segment of the class. The session lasted an average of 57 minutes including the
warmup and cooldown periods. Expired air was collected for the duration of the class (including warmup
and cooldown).
Cycling
Subjects performed 60 minutes of continuous cycling on a Monark 824E cycle ergometer. The first and final
5 minutes were performed at a power output of 1.5 Watts per kilogram body weight for males and 1.2 Watts
per kilogram for females. From the sixth through to the 55th minute, subjects worked at 2.0 and 1.6 Watts
per kg for males and females, respectively. Cadence was maintained at 85-90 rpm.
VO2 Max Test
The VO2 max test was performed on the Monark 824E cycle ergometer using a continuous, step protocol.
The starting load was 85W with step increments of 25W (males) and 17W (females) and step duration of 1
minute. Subjects continued until volitional exhaustion. To represent VO2 max, all subjects achieved the
following criteria: 1) attainment of a heart rate within 10 beats per minute of age-predicted maximum (using
the equation 220 minus age in years); and 2) a respiratory exchange ratio of 1.10 or greater[7]
.
Results
Heart rate and oxygen consumption values during BODYPUMP™ and cycling are presented in Tables 4-6
below. The mean oxygen consumption (expressed relative to body weight) during the BODYPUMP™
sessions was 20.2 ml/kg/min for all subjects combined and 21.5 ml/kg/min, and 19.0 ml/kg/min for males
and females, respectively. The oxygen consumption values for the cycle session were 28.8, 29.4 and 28.2
ml/kg/min for all subjects, males and females, respectively.
Subjects exercised at an average intensity of 40.7% of their VO2 max during the BODYPUMP™ session.
The values for males and females separately were 41.6% and 39.8%. Intensity values during the bike
session were 60.3%, 58.7%, 59.2% of VO2 max for all subjects, males and females, respectively. Subjects
spent an average of 9.8 minutes above 50% VO2 max during the BODYPUMP™ session when expressed
as a group and 11.6 and 8.0 minutes respectively, when separated into males and females. Subjects spent
an average of 1.9 minutes above 70% VO2 max during the BODYPUMP™ session when expressed as a
group and 3.2% and 0.6% for males and females, respectively.
© 2007 Les Mills International Limited 14
The average heart rate during the BODYPUMP™ session was 135.4 beats per minute for the group, and
138.2 and 132.6 for males and females, respectively. During the cycle session these values were 134.1,
136.5 and 131.6 beats per minute for the group, males and females. Subjects spent an average of 38.8
minutes above 70% of maximum heart rate during the BODYPUMP™ session when expressed as a group
and 37.4 and 40.2 minutes when separated into males and females. During the cycle session these values
were 33.6, 32.4 and 34.8 minutes for the group, males and females, respectively. The relatively high heart
rates relative to oxygen consumption during BODYPUMP™ are explained in the discussion.
Table 4: Oxygen consumption and heart rate for all subjects during BODYPUMP™ and cycle sessions
BODYPUMP™
Mean (SD)
Cycle
Mean (SD)
Oxygen consumption (ml/kg/min) 20.24 (3.61) 28.77 (3.24)
Average percentage of VO2 max 40.7 (5.3) 60.3 (12.3)
Number of minutes above 50% VO2 max 9.8 (6.1) 45.7 (19.0)
Number of minutes above 70% VO2 max 1.9 (3.0) 8.0 (17.1)
Average heart rate 135.4 (12.8) 134.1 (19.33)
Average percentage of maximum heart rate 74.2 (4.7) 73.4 (8.7)
Average number of minutes above 70% maximum heart rate 38.8 (9.4) 33.6 (27.7)
VO2 max and maximum heart rate as measured on the cycle during the maximum test
Table 5: Oxygen consumption and heart rate for male subjects during BODYPUMP™ and cycle sessions
BODYPUMP™ Mean (SD)
Cycle Mean (SD)
Oxygen consumption (ml/kg/min) 21.5 (3.4) 29.4 (2.7)
Average percentage of VO2 max 41.6 (5.6) 58.7 (17.6)
Number of minutes above 50% VO2 max 11.6 (7.6) 38.0 (24.8)
Number of minutes above 70% VO2 max 3.2 (3.8) 10.8 (24.1)
Average heart rate 138.2 (13.5) 136.5 (22.6)
Average percentage of maximum heart rate 74.3 (4.7) 73.3 (10.6)
Average number of minutes above 70% maximum heart rate 37.4 (8.3) 32.4 (29.2)
VO2 max and maximum heart rate as measured on the cycle during the maximum test
© 2007 Les Mills International Limited 15
Table 6: Oxygen consumption and heart rate for female subjects during BODYPUMP™ and cycle sessions
BODYPUMP™
Mean (SD)
Cycle
Maen (SD)
Oxygen consumption (ml/kg/min) 19.0 (3.8) 28.2 (4.0)
Average percentage of VO2 maxϒϒϒϒ 39.8 (5.4) 59.2 (5.6)
Number of minutes above 50% VO2 max 8.0 (4.3) 53.4 (7.2)
Number of minutes above 70% VO2 max 0.6 (1.3) 5.2 (10.5)
Average heart rate 132.6 (12.9) 131.6 (17.8)
Average percentage of maximum heart rate 74.1 (5.3) 73.5 (8.3)
Average number of minutes above 70% maximum heart rate 40.2 (11.2) 34.8 (29.6)
VO2 max and maximum heart rate as measured on the cycle during the maximum test
Caloric expenditure and substrate utilization during BODYPUMP™ and cycling are presented in Tables 7-9
below. Subjects burned an average of 411.0 calories during the BODYPUMP™ session when expressed
as a group and 483.1 and 338.9 respectively, when separated into males and females. This equated to 7.2,
8.4 and 5.9 calories per minute for the group, males and females, respectively. The higher values for the
men are related primarily to their greater body weight. The maximum number of calories burned, were 424
for a female, and 603 for a male.
The BODYPUMP™ session led to the consumption of 70.0, 88.6 and 51.5 calories of fat and 340.9, 394.4
and 287.4 calories of carbohydrate for the group, males and females, respectively. This equated to 16.7%
fat and 83.3% carbohydrate for the group as a whole, 18.6% fat and 81.4% carbohydrate for the males,
and 14.9% fat and 85.1% carbohydrate for the females.
Subjects burned an average of 623.3 calories during the cycling session when expressed as a group and
706.3 and 540.2 respectively, when separated into males and females. This equated to 10.5, 12.0 and 9.0
calories per minute for the group, males and females, respectively. The cycle session led to the
consumption of 169.5, 182.1 and 157.0 calories of fat and 453.7, 524.3 and 383.2 calories of carbohydrate
for the group, males and females, respectively. This equated to 27.3% fat and 72.7% carbohydrate for the
group as a whole, 26.4% fat and 73.6% carbohydrate for the males only and 28.2% fat and 71.8%
carbohydrate for the females only.
© 2007 Les Mills International Limited 16
Table 7: Fuel utilization for all subjects during BODYPUMP™ and cycle sessions
BODYPUMP™
Mean (SD)
Cycle
Mean (SD)
Total calories burned 411.0 (99.3) 623.3 (141.4)
Calories per minute 7.2 (1.6) 10.5 (2.5)
Total calories of fat consumed 70.0 (32.9) 169.5 (74.6)
Total calories of carbohydrate consumed 340.9 (74.4) 453.7 (113.5)
Percentage of total calories from fat 16.7 (5.3) 27.3 (10.6)
Percentage of total calories from carbohydrate 83.3 (5.3) 72.7 (10.6)
Table 8: Fuel utilization for male subjects during BODYPUMP™ and cycle sessions
BODYPUMP™
Mean (SD)
Cycle
Mean (SD)
Total calories burned 483.1 (81.9) 706.3 (107.8)
Calories per minute 8.4 (1.3) 12.0 (1.96)
Total calories of fat consumed 88.6 (32.3) 182.1 (62.1)
Total calories of carbohydrate consumed 394.4 (65.0) 524.3 (97.9)
Percentage of calories from fat 18.6 (5.3) 26.4 (7.8)
Percentage of calories from carbohydrate 81.4 (5.3) 73.6 (7.8)
Table 9: Fuel utilization for female subjects during BODYPUMP™ and cycle sessions
BODYPUMP™
Mean (SD)
Cycle
Mean (SD)
Total calories burned 338.9 (49.9) 540.2 (126.9)
Calories per minute 5.9 (0.6) 9.0 (2.1)
Total calories of fat consumed 51.5 (23.2) 157.0 (91.2)
Total calories of carbohydrate consumed 287.4 (32.7) 383.2 (83.4)
Percentage of calories from fat 14.9 (5.0) 28.2 (13.7)
Percentage of calories from carbohydrate 85.1 (5.0) 71.8 (13.7)
Table 10 presents a summary of key results for oxygen consumption, caloric expenditure, and substrate
utilization during BODYPUMP™.
© 2007 Les Mills International Limited 17
Table 10: Summary of key results: BODYPUMP™
VO2
(ml/kg/min)
% VO2 Max Total Kcal Kcal/min % CHO % Fat
All subjects 20.2 40.7 411.0 7.2 83.3 16.7
Men 21.5 41.6 483.1 8.4 81.4 18.6
Women 19.0 39.8 338.9 5.9 85.1 14.9
Blood Lactate Analysis
To ensure that gas analysis during the BODYPUMP™ sessions adequately captured total caloric
utilization, blood lactate samples were taken from seven participants immediately pre- and post a typical
BODYPUMP™ class. This was to determine whether subjects had returned to near-resting lactate levels by
the end of the cooldown. Seven randomly selected individuals (three females, four males) provided
fingertip blood samples that were analyzed using an Accusport Blood Lactate Analyzer (refer to Table 11).
Both the moderate elevation in blood lactate concentration at the cessation of exercise, and previous
studies on EPOC suggest that additional calories are utilized above and beyond those calculated from the
results of gas analysis (see discussion).
Table 11: Blood lactate concentration before and after BODYPUMP™ session
Subject Before class After class
1 2.4 3.1
2 2.1 5.4
3 2.2 3.0
4 1.9 3.1
5 2.4 3.3
6 2.0 2.7
7 2.8 4.6
MEAN 2.3 3.6
Discussion
BODYPUMP™ is a high-repetition, resistance training, choreographed exercise program. The potential
benefits of BODYPUMP™ include: improved muscular endurance, increased aerobic fitness, fat weight
loss, and maintenance of, or increases in, lean body mass. The present study investigated the aerobic
demand and caloric expenditure of a standard session of BODYPUMP™.
The frequency, intensity, duration, and type of exercise determine the effectiveness of an exercise-training
program in reducing body fat and improving the various components of fitness. The most widely followed
© 2007 Les Mills International Limited 18
guidelines for health and fitness are issued by the American College of Sports Medicine (ACSM). The
ACSM’s position standard for the quantity and quality of training for developing and maintaining aerobic
fitness, body composition, and muscular strength and endurance in healthy adults includes the following
recommendations:
Frequency of training: 3-5 days per week
Intensity of training: 60-90% of maximum heart rate or 50-85% of maximum oxygen uptake
Duration of training: 20-60 minutes of continuous aerobic activity
Mode of activity: Any activity the uses large muscle groups, can be maintained continuously, and is
rhythmical and aerobic in nature
Resistance training: Strength training of moderate intensity, sufficient to develop and maintain fat-free
weight should be an integral part of an adult fitness program. One set of 8-12 repetitions of 8-10 exercises
that condition the major muscle groups at least two days per week is the recommended minimum.
BODYPUMP™ is an effective form of training that fulfills the majority of the ACSM criteria in a one hour
session. This section discusses the implications of the results of the present study for the physiological
benefits of BODYPUMP™.
Aerobic Intensity
Subjects worked at an average of 74.2% of maximum heart rate and 40.7 % of maximum aerobic capacity
during the BODYPUMP™ session. These values were similar when males and females were considered
as a group, and separately. Although the average heart rate during BODYPUMP™ was high enough to
meet the ACSM recommendations for developing and maintaining aerobic fitness, the oxygen consumption
was not. Heart rate during BODYPUMP™ is elevated disproportionately to oxygen consumption due to the
pressure effect that occurs during weight-training exercises. For any given level of oxygen consumption,
heart rate is typically 20% higher for upper body exercise than for lower body exercise such as cycling.
The average intensity achieved during the cycle session (60.3% of VO2 max and 73.4% of maximum heart
rate) was higher than that achieved during the BODYPUMP™ session. The time spent above 50% of VO2
max and 70% of VO2 max was also higher during cycling. During the BODYPUMP™ session subjects
spent 10 minutes above 50% of VO2 max and 2 minutes above 70% VO2 max as compared to 46 minutes
above 50% VO2 max and 8 minutes above 70% VO2 max for the cycle session. These results indicate that
the BODYPUMP™ session provides a low to moderate stimulus to increase aerobic fitness. The implication
of these results is that BODYPUMP™ is useful for maintaining aerobic fitness, but does not provide
sufficient stimulus to improve aerobic fitness in already fit subjects such as those who participated in this
study. For subjects such as these, two to three days per week of higher-intensity aerobic-based exercise
would be necessary to improve aerobic fitness. For more sedentary populations, such as middle-aged
© 2007 Les Mills International Limited 19
individuals without a history of aerobic training, BODYPUMP™ would be likely to provide a considerably
higher relative aerobic demand, which would be sufficient to improve aerobic fitness.
Energy Expenditure
A BODYPUMP™ session utilized an average of 411 calories for the subjects in this study. The males and
females utilized an average of 483 and 339 calories, respectively. The highest number of calories utilized
by a male subject during BODYPUMP™ was 586, while the highest energy expenditure for a female
subject was 437 calories. Although total calories utilized were greater during the cycle session than during
the BODYPUMP™ session, the results indicate that both modes of exercise are effective for promoting
weight loss.
The cycle session consumed a greater proportion of fat than the BODYPUMP™ session (27.3% compared
to 16.7%) and there were no significant differences between males and females for these values. The
contribution that fat and carbohydrate make to the fuel mix is dependent on the intensity of the exercise;
the higher the intensity the smaller the contribution from fat. The BODYPUMP™ class required intermittent
bursts of high-intensity, effort, which used exclusively carbohydrate as fuel. In contrast, the cycle session
was a period of consistent moderate-intensity exercise which allowed a larger contribution from fat.
However as previously explained, it is the number of calories burned rather than the source of those
calories which determines energy balance and weight loss.
The magnitude of excess post-exercise oxygen consumption’s (EPOC) contribution to caloric expenditure
during BODYPUMP™ was not measured. The results of the studies presented in Table 2, however,
suggest that for an hour of exercise similar to BODYPUMP™ the expected caloric expenditure related to
EPOC would be approximately 15% of total caloric expenditure. EPOC would, therefore, be expected to
contribute approximately an additional 62 calories to the average of 411 calories utilized by the subjects in
this study, increasing total caloric expenditure due to a session of BODYPUMP™ to 473. Including the
contribution of EPOC would increase total caloric expenditure due to a session of BODYPUMP™ to an
average of 556 calories for the males, and 390 for the females. The number of BODYPUMP™ sessions
required to lose one kilogram of body fat (7,700 calories), therefore, is 16.3 for the average subject, 13.8 for
the average male, and 19.7 for the average female in this study. A subject who did not change his or her
dietary intake, and who added three sessions of BODYPUMP™ per week could expect to lose 1 kilogram
of body fat in four to six weeks.
© 2007 Les Mills International Limited 20
Additional Benefits of BODYPUMP™
Additional benefits of BODYPUMP™ include likely improvements in muscular endurance, maintenance of
lean body mass and social interaction. Muscular endurance is defined as the ability of a muscle to
repeatedly produce force over time and resist fatigue[17]
and can be increased most effectively by low-
resistance, high-repetition exercise. Although the effect of BODYPUMP™ sessions on muscular endurance
was not measured in this study, the moderate load, high-repetition nature of BODYPUMP™ fits the
requirements for improving muscular endurance. Measurement of this benefit is an area for future
investigation. The use of challenging loads by some individuals during BODYPUMP™ sessions may result
in absolute strength gains and muscular hypertrophy. It is unlikely that strength gains and hypertrophy
would occur for already fit subjects such as those who participated in the present study; however, for
individuals without a history of resistance training, BODYPUMP™ may provide sufficient stimulus to elicit
strength gains.
To maintain and/or increase lean body mass requires stimulation of muscle mass. Although the present
study did not track lean body mass over time, the resistance exercises performed during BODYPUMP™
certainly appear to be sufficient for the maintenance of lean body mass. The whole body resistance training
of BODYPUMP™ suggests that this program is more effective in maintaining or increasing lean body mass
than is cycling. This is an additional area for future investigation.
Finally, the social interaction provided by a BODYPUMP™ class provides enjoyment and a motivating
environment which encourages adherence to the exercise program. The greatest health and fitness
challenge to the average individual is maintaining a regular exercise routine. The positive social
atmosphere of a BODYPUMP™ session is likely to lead to enhanced enjoyment and improved adherence
which will lead to greater long-term benefits to health and fitness.
© 2007 Les Mills International Limited 21
References
1. Chad, K.E. and Wenger, H.A. (1985). The effects of duration and intensity on the exercise and
post-exercise metabolic rate. The Australian Journal of Science and Medicine in Sport. 17(45):14-18.
2. Dawson, B., Straton, S. and Randall, N. (1996). Oxygen consumption during recovery from
prolonged sub-maximal cycling below the anaerobic threshold. Journal of Sports Medicine and Physical
Fitness. 36:77-84.
3. Elliot, D.L., Goldberg, L. and Kuehl, K.S. (1992). Effect of resistance training on excess post-
exercise Oxygen consumption. Journal of Applied Sport Science Research. 6(2):77-81
4. Frayn, K.N. (1983). Calculation of substrate oxidation rates in vivo from gaseous exchange.
Journal of Applied Physiology. 55(2):628-634.
5. Fox, E.L., Bowers, R.W. and Foss, M.L. (1993). The Physiological Basis for Exercise and Sport.
(Fifth edition). Brown and Benchmark: Madison, Wisconsin.
6. Hawley, J.A., Brouns, F. and Jeukendrup, A. (1998). Strategies to enhance fat utilization during
exercise. Sports Medicine. Apr; 25(4), p241-257.
7. Issekutz, B., Birkhead N.C and Rodahl K (1962) Use of respiratory quotients in assessment of
aerobic work capacity. J. Appl. Physiol. 17:47-57.
8. Martin, W.H. (1997). Effect of endurance training on fatty acid metabolism during whole body
exercise. Medicine and Science in Sports and Exercise. 29:635-639.
9. Melby, C.L. and Hill, J.O. (1999). Exercise macronutrient balance, and body weight regulation.
Sports Science Exchange. SSE #72, 12(1).
10. Mole, P.A. (1990). Impact of energy intake and exercise on resting metabolic rate. Sports
Medicine. 10(2):72-87.
11. Neiman, D.C., Haig, J.L., De Guia, E.D., Dizon, G.P.and Register, U.D. (1988). Reducing diet and
exercise training effects on resting metabolic rates in mildly obese women. Journal of Sports Medicine and
Physical Fitness. 28:79-88.
12. Olds, T.S. and Abernethy, P.J. (1993). Post-exercise oxygen consumption following heavy and
light resistance exercise. Journal of Strength and Conditioning Research. 7(3):147-152.
© 2007 Les Mills International Limited 22
13. Peronnet, F. and Massicotte, D. (1991). Table of non-protein respiratory quotient: An update.
Canadian Journal of Sport Science. 16(1):23-29.
14. Puhl, S.M. & Clark, K. (1992). Exercise intensity and body fat loss. National Strength and
Conditioning Association Journal. 14(6):16-18.
15. Quinn, T.J., Vroman, N.B. and Kretzer, R. (1994). Post-exercise oxygen consumption in trained
females: effect of exercise duration. Medicine and Science In Sports and Exercise. 26(7):908-913.
16. Sedlock, D.A., Fissinger, J.A. and Melby, C.L. (1989). Effects of exercise intensity and duration on
post exercise energy expenditure. Medicine and Science in Sports and Exercise. 21:626-631.
17. Zatsiorsky, V.M. (1995). Science and Practice of Strength Training. Human Kinetics; Champaign,
Il.
“Creating life-changing fitness experiences everytime, everywhere”
© 2007 Les Mills International Limited 23
An AttitudiAn AttitudiAn AttitudiAn Attitudinal Study on thenal Study on thenal Study on thenal Study on the
BODYPUMPBODYPUMPBODYPUMPBODYPUMP WORKOUT WORKOUT WORKOUT WORKOUT
International Survey Company A C Nielsen (1999)
Objectives
This research examines the opinions and attitudes towards the BODYPUMP™ workout amongst regular
attendees. For the purposes of this study, a regular attendee comprises anyone who has been going to
BODYPUMP™ classes twice a week or more, on average, for at least three months.
To examine the opinions and attitudes of these people, we asked:
a) The degree to which people enjoyed a variety of different aspects of the BODYPUMP™ workout;
b) The different benefits people believe they gain from attending BODYPUMP™ classes, including
muscle toning and fat loss;
c) The incidence of injuries incurred by regular participants and which parts of the body were injured;
e) A variety of demographic information, including age, gender and other sporting activities.
Methodology
The target group for this research was current members of Les Mills World of Fitness in Auckland who
were regular BODYPUMP™ class attendees.
Our target audience was reached using Les Mills’ membership list and screening for people who were
regular attendees of BODYPUMP™.
Two questionnaires were developed in consultation with Les Mills International. Both were conducted using
Computer Assisted Telephone Interviewing (CATI) and allowed for up to three call-backs to phone eligible
contacts before replacing one contact with another. All interviewing was conducted in the evenings and
during the weekends.
The first questionnaire lasted 10 minutes and covered the majority of the research objectives, while the
second lasted 5 minutes and was designed to get greater detail and an annualized rate on injuries.
Interviewing was conducted between 17 March and 7 April 1999 for the initial questionnaire and between
31 May and 6 June 1999 for the second. The final sample size was 200 respondents.
© 2007 Les Mills International Limited 24
Results
Enjoyment of BODYPUMP™
Gym members were very positive about their enjoyment of the BODYPUMP™ classes. At least 90%
agreed that:
a) The routines are easy to follow (97%);
b) BODYPUMP™ classes provide a challenging workout (93%);
c) The instructors are friendly and helpful (90%).
In addition, agreement with the remaining enjoyment factors was over 70%.
a) BODYPUMP™ classes are fun (89%);
b) BODYPUMP™ classes have improved my overall feeling of well-being (86%);
c) Attending BODYPUMP™ classes improves my performance in other sports and exercise activities
(72%).
Even amongst statements with less than 90% agreement, the level of disagreement was very low. People
who didn’t agree with a statement preferred to say they neither agreed nor disagreed.
Benefits of BODYPUMP™
Gym members were asked how strongly they felt they received certain physical benefits from attending
BODYPUMP™. It is important to remember the responses represent perceived benefits and not
necessarily actual benefits received.
Quite clearly, the two benefits members most strongly felt they got from BODYPUMP™ related to muscular
development:
a) Improved strength (95%);
b) Improved muscle tone (93%).
Respondents also felt that the benefit of lower body fat applied quite strongly to them. Half were positive,
saying this benefit applied to them (52%), and a further 39% were neutral. Only 8% said they didn’t feel this
benefit applied to them.
Of the remaining statements concerning the physical benefits of BODYPUMP™, the proportions of people
who felt that each benefit applied to them were as follows:
a) Improved cardiovascular fitness (34%);
b) Improved coordination (30%);
© 2007 Les Mills International Limited 25
c) Lower body weight (29%);
d) Improved flexibility (26%).
Except for the strength/muscle tone benefits, there were relatively high levels of neutral ratings across all
the statements. This suggests people are often unsure whether their body has improved. It is possible they
are mistaking an increase, or lack of decrease, in body weight brought about by better muscle mass as
meaning they haven’t lost fat.
Injuries Resulting From BODYPUMP™
The injury rate amongst BODYPUMP™ attendees was measured by the incidence of significant injuries
sustained in the past three months as a direct result of attending a BODYPUMP™ class. A significant
injury was defined as an injury that required professional attention or one that prevented a respondent from
attending BODYPUMP™ classes for at least two weeks.
Across the sample as a whole, the three-month rate of injury was 1.57%. Of the three people injured (on a
base of 188), two injured their backs and one their shoulder. All three sought professional attention for
their injuries - one consulted a physiotherapist, one a masseur, and the third an orthopedic specialist.
Likelihood of Continuing BODYPUMP™ Classes
Ninety two percent of respondents said they were likely to continue going to BODYPUMP™ classes in the
next six months; 84% of the sample said they were very likely to continue going.
Amongst this 92%, most (79%) said they would continue to attend BODYPUMP™ with the same degree of
regularity as they do now.
A positive result is that amongst the remainder of these respondents, 17% said they planned to increase
their frequency while only 3% said they planned to decrease it.
The intention to increase BODYPUMP™ class frequency is more likely amongst younger (under 35 years,
23%) rather than older (35 years and older, 8%) members.
Comments on BODYPUMP™
Three-quarters of the respondents (78%) provided open-ended comments on BODYPUMP™.
Amongst people who made a comment, the majority were very positive:
a) Great class/very happy with class/excellent (40%);
b) Great instructors (19%);
c) Gives good results/effective (14%);
d) Interesting/fun/avoids monotony (11%);
© 2007 Les Mills International Limited 26
e) Music is good/they regularly vary the music (7%);
f) Caters to your fitness level/able to work out at your own level (6%).
The more negative comments included:
• Pay more attention to people’s technique/give tips on technique (14%)
• Routines are monotonous/need to vary program sometimes (10%)
• Classes too crowded/large (8%)
• Music boring/change the music/better variety of music (7%)
• Instructors inconsistent/some good, some poor (7%).
Below are some actual verbatim responses that Les Mills International recorded. All comments have been
attributed with respondents’ permission, knowing that the comments may be used for promotional
purposes.
“I think they are absolutely fantastic, keep it up. I think it’s great. I want to make sure they keep it up. I’ve
had two babies and it [BODYPUMP™] has helped me get back into shape, it helped my overall stamina
during pregnancy, and helped me get my body back after having the babies. It helped my overall fitness
levels. It helped me get through the pregnancy.”
- Annika Lane
“BODYPUMP™ rocks for getting all-round toning up of the muscles. Having worked out for about 16 years
it has been the most efficient way of converting my fat to muscle.”
- Simon Clark
“It’s [BODYPUMP™] just awesome. You can work at your own level. It’s a little bit social which is good.”
- Sharon Amphlett
“I think overall it’s [BODYPUMP™] fantastic, especially when you’re short on time. It gives you the muscle
tone and fitness so if you don’t have much time it’s an excellent workout.”
- Lauren Barriball
It [BODYPUMP™] is the best thing I’ve ever done in terms of workout. If you haven’t done it you have to do
it, it’s addictive.”
- Tracey Thompson
© 2007 Les Mills International Limited 27
Other Sporting Activities BODYPUMP™ Members Take Part In
Other gym-based activities* (53%), running (32%) and walking (27%) are the main activities outside of
BODYPUMP™ that members take part in.
Looking at gym-based activities in more detail, 25% of the sample listed their activities outside of
BODYPUMP™ as general gym exercising (eg circuit training, boxing, etc.), 21% said aerobics and just 7%
said weight training.
* Gym-based activities include mentions of gym, aerobics and weights.
© 2007 Les Mills International Limited 28
Summary Discussion
The most positive aspects of BODYPUMP™ based on the findings of this report are the high levels of
enjoyment amongst attendees and the physical benefits of improved muscle tone and strength.
Attendees appeared unsure about whether BODYPUMP™ had helped them with other aspects of their
physical conditioning. It is possible, as was stated in the text, that attendees are mistaking an increase or
lack of decrease in body weight brought about by an increase in muscle mass as meaning they haven’t lost
fat. It may be that people need to be made more aware of this idea and the need to judge their progress by
body composition and body fat readings, as well as their ability over time to progress through each
BODYPUMP™ workout.
BODYPUMP™ has a low injury rate which suggests a very user-friendly format well suited to people who
attend the classes. People did comment, however, on wanting to see instructors help people with poor form
Just 9 out of 10 people said they were likely to continue going to the classes. Younger members are more
likely then older members to actually consider increasing the frequency of attendance at BODYPUMP™.
This is a positive sign – these are the people who have the potential to be the longest-serving
BODYPUMP™ class attendees.
BODYPUMP™ members appear to enjoy aerobic activity even when they are not attending classes – other
gym work (emphasis on the aerobic side) and running and walking.
© 2007 Les Mills International Limited 29
THE PHYSICAL AND PSYCHOLOGICAL RESPONSE TO 13 WEEKS oF STRUCTURED GROUP-FITNESS EXERCISE IN UNTRAINED INDIVIDUALS
LYTHE, J, PFITZINGER, P & HO, D. UNISPORTS CENTER FOR SPORT PERFORMANCE, UNIVERSITY OF AUCKLAND (2000)
Introduction
Group exercise fitness classes have grown in popularity over the past 20 years. Aerobics is now a term that
encompasses a broad range of these group exercise classes from bench step classes to choreographed
Martial Arts classes. A leading organization in the aerobics market is Les Mills International (LMI). LMI have
developed the Les Mills™ Body Training Systems product range which includes BODYPUMP™,
BODYSTEP™, BODYATTACK™, BODYCOMBAT™, and RPM™. The acute effects (aerobic intensity and
caloric expenditure) of these classes have been previously studied [1] but the longitudinal effects of
participation have not. The purpose of this study was to measure the effect of 13 weeks of group exercise
classes on the physical and psychological condition of untrained adults.
Methods
A total of 150 subjects volunteered for the study. They were randomly selected from 500 individuals that
responded to an advertisement in the national newspaper. Subjects were required to be between the ages
of 16 and 60 and to have been inactive for a period of at least six months. The characteristics of the
subjects at the commencement of the study are shown below (Table 1).
Table 1: Descriptive characteristics of subjects who commenced the study
All Subjects Males Females
n 150 68 82
Age (yrs) 35.0 (10.1) 35.9 (9.7) 34.2 (10.4)
Weight (kg) 78.5 (16.1) 88.1 (12.4) 70.6 (14.3)
Height (cm) 171.6 (10.0) 179.3 (8.8) 165.2 (6.8)
All subjects were given a detailed written information pack as well as a verbal explanation of the study
before being asked to participate. Informed consent was obtained from every subject. The study lasted 15
weeks and a timeline of events is shown below (Figure 1).
© 2007 Les Mills International Limited 30
Figure 1: Project timeline
Test Descriptions
All subjects performed a battery of fitness tests prior to the intervention being commenced. A number of
testing sessions were scheduled over the course of a week to enable all subjects to be tested at their
convenience. Each session was of approximately 90 minutes duration and was attended by 3-10 subjects.
Tests were performed at the facilities of UniSports Center for Sport Performance by suitably qualified staff.
The tests measured aerobic fitness, body composition, upper body strength and muscular endurance,
lower body strength and muscular endurance and psychological well-being. During all tests the
administrators provided consistent verbal encouragement. Details of each test are given below.
Multi-stage shuttle run test
The multi-stage shuttle run test or ‘beep test’ provides a very simple measure of aerobic endurance. The
test requires subjects to run back and forth between two lines that are 20 meters apart. Subjects must run
at a pace that is set by an audiotape. As the test progresses the subjects must increase their running
speed to stay at the pace of the tape. The point that each subject can no longer keep up with the pace is
the end of the test. The test administrator stops a subject when they fall behind the beep on two
consecutive lengths. Subjects receive a numeric score that indicates the number of 20-meter lengths
successfully completed.
Body composition
Body mass was measured to the nearest 0.1 kg using Seca alpha electronic scales. Height was measured
to the nearest 0.5 cm using a stadiometer. Skinfolds were taken using Slimguide calipers in accordance
with ISAK procedures at the following sites: triceps, subscapular, biceps, iliac crest, supraspinale,
abdominal, thigh and calf. A sum of eight skinfolds was used as the primary measure of body fatness. Two
additional body composition variables were then derived. Body mass index (BMI) was calculated using the
following formula:
BMI = weight (kg) / height (m2).
Percentage of body fat was calculated first by using the formula for body density provided by Durnin and
Womersley (1974) and then the formulae for percent body fat by Siri (1961).
BD (males) = 1.1765 – 0.0744 (log10∑S4skinfolds)
Week 1
Pre-test
Weeks 2-14
Intervention
Week 15
Post-test
© 2007 Les Mills International Limited 31
BD (females) = 1.1567 – 0.0717(log10∑S4skinfolds)
% BF = (4.95/BD-4.50) x 100
These formulae were chosen as they best represented the mix of age and race provided in the sample.[4]
Upper body strength and muscular endurance
The bench press exercise was used as a measure of both upper body strength and upper body muscular
endurance. This exercise was performed with a barbell and weights. After a period of familiarization the
subjects, six repetition maximum (6RM) was determined by having them perform sets of six repetitions at
progressively increasing loads. Subjects used a slightly-wider-than-shoulder-width grip on the bar and were
required to keep their lower back and hips in contact with the bench during the lowering and pressing
movements. The 6RM was the heaviest load successfully lifted for six repetitions. Muscular endurance was
measured by having the subject complete as many repetitions as possible using a load equal to 70% of
their 6RM. During both tests a movement tempo of 1 second to raise the weight and 1 second to lower the
weight was enforced.[5, 6]
Lower body strength and muscular endurance
The horizontal leg press exercise was used as a measure of both lower body strength and lower body
muscular endurance. This exercise was performed using a pin-loaded machine (Fitness Works, Auckland).
Subjects were required to perform a specific range of motion on every repetition. The range of motion was
from 90o of knee flexion to 5
o of knee flexion. After a period of familiarization for the subjects, six repetition
maximum (6RM) was determined by having each subject perform sets of six repetitions at progressively
greater loads. The 6RM load was the heaviest load successfully lifted for six repetitions. Muscular
endurance was measured by having the subject complete as many repetitions as possible using a load
equal to 70% of their 6RM. As for the bench press, a movement tempo of 1 second to raise the weight and
1 second to lower the weight was enforced.
Psychological state
Psychological state was assessed using a questionnaire (Refer to Appendix B). Subjects were required to
rate themselves on a five-point scale with regard to 10 positive and 10 negative emotions. The
questionnaire was scored by adding together the ratings from the positive questions then subtracting the
ratings from the negative questions. This system provided a scoring range of –40 to +40.
Intervention
This was a single intervention study with an exercise program being the intervention.
© 2007 Les Mills International Limited 32
Group exercise classes
From the start of week 2 until the end of week 14 (13 weeks of activity) subjects were required to attend
group exercise classes at the facilities of Les Mills World of Fitness in Auckland. Subjects were randomly
allocated into five groups and each group performed a different group exercise class. The groups were:
BODYPUMP™, BODYSTEP™, BODYATTACK™, BODYCOMBAT™ and RPM™. Subjects were only
permitted to perform the class to which they were allocated. They were required to attend between two and
five sessions per week and must have performed a total of 32 sessions by the end of the 14th week to be
included in the analysis. Introductory sessions were offered to all participants to ensure that they were
skilled in the movements of each class prior to commencement of the program.
Diet
Subjects were instructed not to change their diet. A three-day diet record was obtained for a sample of
subjects during week 1 and during week 14. These diet records were compared to see if caloric intake or
composition was significantly altered during the study.
Data Analysis
All test data was entered into a specially designed Microsoft Excel spreadsheet. Each group’s results were
pooled so that pre- and post-intervention data could be compared. T-tests were used to determine if post-
intervention test data was significantly different to pre-intervention data.
Results
Table 2: Initial descriptive characteristics of subjects who completed the study
All subjects Males Females
n 79 37 42
Age (yrs) 36.1 (9.6) 36.1 (8.1) 36.1 (10.9)
Weight (kg) 78.1 (15.7) 87.5 (11.3) 70 (14.8)
Height (cm) 171.4 (10.2) 179.6 (7.8) 164.3 (6.1)
© 2007 Les Mills International Limited 33
Table 3: Initial descriptive characteristics of subjects who performed BODYPUMP™ and completed the study
All subjects Males Females
n 40 16 24
Age (yrs) 40.5 (10.9) 41.1 (8.8) 40 (12.3)
Weight (kg) 77.0 (16.5) 88.1 (11.1) 69.1 (15.3)
Height (cm) 170.8 (11.0) 180.8 (8.1) 163.7 (6.3)
Table 4: Initial descriptive characteristics of subjects who performed BODYATTACK™ and completed the study
All subjects Males Females
n 8 5 3
Age (yrs) 29.9 (6.1) 29.4 (6.2) 30.7 (7.1)
Weight (kg) 83.1 (16.7) 90.2 (16.1) 71.2 (11.4)
Height (cm) 171.6 (6.8) 175.1 (4.3) 165.7 (6.5)
Table 5: Initial descriptive characteristics of subjects who performed BODYSTEP™ and completed the study
All subjects Males Females
n 11 8 3
Age (yrs) 34.0 (5.4) 35.9 (3.0) 29.0 (8.0)
Weight (kg) 82.4 (17.4) 89.9 (13.6) 62.3 (5.2)
Height (cm) 176.6 (11.4) 181.2 (8.3) 164.2 (9.8)
Table 6: Initial descriptive characteristics of subjects who performed BODYCOMBAT™ and completed the study
All subjects Males Females
n 10 3 7
Age (yrs) 31.0 (3.6) 30.0 (1.7) 32.3 (4.2)
Weight (kg) 74.1 (9.1) 81.9 (4.3) 67.8 (6.5)
Height (cm) 168.8 (7.8) 173.3 (9.3) 165.1 (4.6)
Table 7: Initial descriptive characteristics of subjects who performed RPM™ and completed the study
All subjects Males Females
N 10 5 5
Age (yrs) 31.2 (5.8) 31.0 (4.9) 31.4 (7.3)
Weight (kg) 86.5 (14.3) 88.4 (9.6) 84.6 (18.9)
Height (cm) 173.9 (8.5) 179.7 (6.8) 168.2 (5.8)
© 2007 Les Mills International Limited 34
Table 8: Change in skinfolds of subjects as a result of the intervention
Mean (SD) sum of 8 skinfolds (mm)
Pre Post Change T-test
Group 176.2 (59.4) 145.3 (50.4) 29.9 (22.9) 0.000
Males 152.3 (47.8) 127.5 (45.3) 23.7 (21.7) 0.000 BODYPUMP™
Females 192.1 (62.0) 157.1 (51.0) 33.8 (23.2) 0.000
Group 198.4 (52.7) 167.5 (49.4) 31.0 (34.6) 0.039
Males 189.1 (49.5) 178.6 (56.9) 10.6 (12.7) 0.136 BODYATTACK™
Females 214.0 (65.0) 149.0 (35.4) 65.0 (32.9) 0.048
Group 176.4 (62.0) 153.8 (53.8) 22.6 (23.8) 0.015
Males 122.5 (61.1) 123.2 (61.0) -0.7 (3.9) 0.794 BODYCOMBAT™
Females 199.4 (49.6) 166.9 (49.3) 32.6 (21.5) 0.007
Group 163.7 (40.8) 154.3 (38.9) 9.4 (26.1) 0.259
Males 159.9 (40.4) 151.4 (39.9) 8.4 (24.6) 0.365 BODYSTEP™
Females 174.0 (48.9) 162.0 (43.4) 12.0 (35.5) 0.618
Group 189.2 (62.9) 161.5 (58.9) 27.7 (23.3) 0.005
Males 139.3 (41.2) 127.2 (50.3) 12.1 (16.6) 0.179 RPM™
Females 239.0 (31.3) 195.7 (48.4) 43.3 (18.3) 0.006
Table 9: Change in percent body fat of subjects as a result of the intervention
Mean (SD) percent body fat
Pre Post Change T-test
Group 32.2(5.9) 29.5 (6.4) 2.7 (2.0) 0.000
Males 27.8 (4.4) 25.0 (5.2) 2.9 (2.7) 0.000 BODYPUMP™
Females 35.2 (4.9) 32.5 (5.3) 2.6 (1.6) 0.000
Group 33.0 (4.6) 31.2 (5.3) 1.8 (2.1) 0.039
Males 31.1 (3.6) 29.5 (4.4) 1.6 (1.4) 0.074 BODYATTACK™
Females 36.3 (5.4) 33.9 (6.5) 2.3 (3.2) 0.33
Group 31.7 (8.5) 30.4 (7.6) 1.3 (1.9) 0.054
Males 22.8 (8.3) 22.8 (7.9) 0.0 (1.1) 0.946 BODYCOMBAT™
Females 35.6 (5.2) 33.7 (5.0) 1.9 (1.9) 0.038
© 2007 Les Mills International Limited 35
Group 29.6 (5.1) 29.0 (5.7) 0.6 (2.9) 0.558
Males 27.6 (3.7) 27.0 (4.9) 0.6 (3.0) 0.581 BODYSTEP™
Females 34.7 (5.1) 34.4 (4.1) 0.3 (3.3) 0.882
Group 32.4 (7.7) 30.3 (7.7) 2.2 (2.7) 0.031
Males 25.8 (4.4) 24.8 (6.8) 1.1 (3.3) 0.512 RPM™
Females 39.1 (1.8) 35.8 (3.3) 3.3 (1.5) 0.009
The results indicate that subjects made an average reduction in body fat (as represented by skinfolds) of
21.3mm. When expressed in terms of percent body fat the reduction was 2.1%. The BODYPUMP™ group
had the largest reduction of the five classes. Skinfolds decreased by 29.9mm and percent body fat
decreased by 2.7%. This group also had the largest sample (40 subjects) which gave the results a high
level of statistical and practical significance. Males and females had similar percent body fat reductions in
the BODYPUMP™ group with 2.9% and 2.6% reductions respectively. The BODYATTACK™ group had an
average decrease in skinfolds of 31.0mm, equal to a reduction of 1.8% body fat. Females had a slightly
greater decrease in percent body fat than the males (2.3% as compared to 1.8%) but the small sample size
reduces the power of this observation. The BODYCOMBAT™ group had an average decrease in skinfolds
of 22.6mm, equal to a reduction in percent body fat of 1.3%. Within the group, however, it was evident that
the females were responsible for all the reductions in skinfolds and percent body fat. The males did not
reduce skinfolds or percent body fat while the females had reductions of 22.6mm and 1.9% respectively.
The BODYSTEP™ group decreased skinfolds by 9.4mm, equal to a reduction in percent body fat of 0.6%.
Both males and females had similar reductions within the BODYSTEP™ group. The RPM™ group had an
average decrease in skinfolds of 27.7mm, equal to a 2.2% decrease in percent body fat. Females
decreased by a larger amount than males with reductions of 43.3mm and 3.3%, compared to the males
with 12.1mm and 1.1%.
Table 10: Change in aerobic fitness as a result of the intervention
Mean (SD) beep test level
Pre Post Change T-test
Group 41.0 (23.4) 46.0 (26.0) 5.1 (6.8) 0.000
Males 55.3 (23.4) 61.5 (28.5) 6.3 (8.5) 0.009 BODYPUMP™
Females 31.5 (18.2) 35.7 (18.5) 4.3 (5.6) 0.001
Group 44.9 (23.6) 58.3 (26.4) 13.4 (8.1) 0.002
Males 50.2 (26.9) 64.9 (27.9) 14.4 (9.1) 0.024 BODYATTACK™
Females 36.0 (17.7) 47.7 (25.0) 11.7 (7.4) 0.111
© 2007 Les Mills International Limited 36
Group 55.6 (30.6) 66.0 (27.3) 10.4 (8.2) 0.003
Males 86.7 (30.0) 96.0 (23.6) 9.3 (6.4) 0.128 BODYCOMBAT™
Females 42.3 (20.4) 53.1 (16.9) 10.9 (9.3) 0.022
Group 58.4 (20.8) 72.9 (25.8) 14.5 (10.8) 0.001
Males 63.4 (21.2) 80.1 (24.1) 16.8 (11.1) 0.004 BODYSTEP™
Females 45.0 (14.7) 53.7 (23.3) 8.7 (8.7) 0.228
Group 50.2 (27.6) 59.5 (30.2) 9.3 (10.2) 0.018
Males 72.4 (19.0) 84.0 (14.5) 11.6 (11.9) 0.095 RPM™
Females 28.0 (11.1) 35.0 (18.6) 7.0 (8.9) 0.154
The results indicate that subjects made an average improvement in beep test score of 7.9 (9.2) lengths.
The average beep test score improved from 46.8 lengths (standard deviation of 24.9) to 56.1 lengths
(standard deviation of 27.8). This represents a change in VO2 max from 34.9 (27.1) to 38.2(27.8), an
improvement of 3.3 (3.8) ml/kg/min. The BODYPUMP™ group improved from 41.0 (23.4) to 46.0 (26.0)
lengths. This represents an increase in VO2 max of 2.0 ml/kg/min from 32.6 (26.0) to 34.6 (27.2) ml/kg/min.
Males from the BODYPUMP™ group scored higher than females on the beep test although the
improvements were similar. The average difference in VO2 max between males and females at the
commencement of the study was 8.6 ml/kg/min or 23.8 lengths of the beep test. The BODYATTACK™
group improved from 44.9 (23.6) to 58.3 (26.4) lengths. This represents an increase in VO2 max of 4.7
ml/kg/min from 34.2 (26.2) to 38.9 (27.4) ml/kg/min. Similar to the BODYPUMP™ group, males had higher
pre and post- scores for the beep test (an average difference in VO2 max at the commencement of the
study was 5.1ml/kg/min or 14.2 lengths of the beep test.) The BODYCOMBAT™ group improved from 55.6
(30.6) to 66.0 (27.3) lengths. This represents an increase in VO2 max of 3.4 ml/kg/min from 38.0(28.9) to
41.4 (27.7) ml/kg/min. Similar to the BODYPUMP™ and BODYATTACK™ groups, males had higher pre
and post- scores for the beep test (an average difference in VO2 max at the commencement of the study
was 14.5 ml/kg/min or 44.4 lengths of the beep test). The BODYSTEP™ group improved from 58.4 (20.8)
to 72.9 (25.8) lengths. This represents an increase in VO2 max of 4.6 ml/kg/min from 38.9 (22.9) to 43.5
(27.1) ml/kg/min. BODYSTEP™ males had higher pre and post- scores for the beep test (an average
difference in VO2 max at the commencement of the study was 6.3 ml/kg/min or 18.4 lengths of the beep
test and they also had greater improvements over the 13 weeks. The RPM™ group improved from 50.2
(27.6) to 59.5 (30.2) lengths. This represents an increase in VO2 max of 3.3 ml/kg/min from 36.0 (27.7) to
39.3 (28.8) ml/kg/min. RPM™ males had higher pre and post- scores for the beep test (an average
difference in VO2 max at the commencement of the study was 15.5 ml/kg/min or 44.4 lengths of the beep
test. The improvements over the 13 weeks were similar for males and females.
© 2007 Les Mills International Limited 37
Table 11: Change in upper body strength as a result of the intervention
Mean (SD) 6RM bench press (kg)
Pre Post Change T-test
Group 33.0 (14.8) 38.1 (15.0) 5.2 (5.4) 0.000
Males 47.0 (11.7) 52.8 (10.9) 6.0 (5.8) 0.001 BODYPUMP™
Females 23.6 (7.5 ) 28.4 (7.5) 4.7 (5.3) 0.000
Group 36.4 (12.5) 45.8 (19.4) 9.4 (8.6) 0.017
Males 43.0 (10.8) 54.0 (18.8) 11.0 (8.8) 0.049 BODYATTACK™
Females 25.3 (4.5) 32.2 (12.7) 6.8 (9.4) 0.340
Group 41.3 (22.4) 46.7 (24.3) 5.4 (10.5) 0.143
Males 68.3 (17.6) 69.2 (20.1) 0.8 (3.8) 0.742 BODYCOMBAT™
Females 29.7 (11.3) 37.0 (19.7) 7.3 (12.1) 0.163
Group 45.0 (18.8) 50.1 (21.8) 5.1 (5.5) 0.011
Males 53.8 (13.4) 60.2 (15.4) 6.4 (5.0) 0.008 BODYSTEP™
Females 21.7 (3.1) 23.3 (8.5) 1.7 (6.3) 0.693
Group 43.3 (21.8) 47.5 (22.0) 3.8 (6.0) 0.079
Males 55.5 (22.4) 59.5 (23.5) 4.0 (6.8) 0.256 RPM™
Females 28.1 (6.9) 32.5 (3.5) 3.5 (6.0) 0.271
Upper body strength as measured using the bench press increased from 37.3 (17.4) kg to 42.8 (18.8) kg.
The BODYPUMP™ group increased from 33.0 (14.8) kg to 38.1 (15.0) kg. Although the males had higher
initial test scores for the bench press the level of improvement was similar with males increasing their
bench press by 6.0 (5.8) kg and females by 4.7 (5.3) kg. These increases were statistically significant. The
BODYATTACK™ group had the largest increase in bench press. Subjects improved from 36.4 (12.5) kg to
45.8 (19.4) kg, an increase of 9.4 (8.6) kg. Male subjects started at a higher level and increased their bench
press more than the females. They started at 43.0 (10.8) and increased by 11.0 (8.8) kg as compared to
the females who started at 25.3 (4.5) and increased by 6.8 (9.4). The increases achieved by
BODYATTACK™ males and females were statistically significant. The BODYCOMBAT™ group increased
from 41.3 (22.4) kg to 46.7 (24.3) kg, an increase of 5.4 (10.5) kg. Males from the BODYCOMBAT™ group
started at a higher level but improved by a much smaller amount than the females. Males started at 68.3
(17.6) and increased by 0.8 (3.8) kg as compared to the females who started at 29.7 (11.3) kg and
increased by 7.3 (12.1) kg. Only the increase achieved by the females was statistically significant. The
BODYSTEP™ group increased from 45.0 (18.8) kg to 50.1 (21.8) kg, an increase of 5.1 (5.5) kg. Males
started at a higher level in the bench press and improved to a greater degree than females. Males started
© 2007 Les Mills International Limited 38
at 53.8 (13.4) and increased by 6.4 (5.0) kg as compared to the females who started at 21.7 (3.1) kg and
increased by 1.7 (6.3) kg. Only the increase achieved by the males was statistically significant. The RPM™
group increased from 43.3 (21.8) kg to 47.5 (22.0) kg, an increase of 3.8 (6.0) kg. Males and females
improved to a similar degree. Males started at 55.5 (22.4) and increased by 4.0 (6.8) kg as compared to the
females who started at 28.1 (6.9) kg and increased by 3.5 (6.0) kg. Neither the male or female group
increases were statistically significant.
Table 12: Change in upper body muscular endurance as a result of the intervention
Mean (SD) number of repetitions of the bench press at 70% of 6RM
Pre Post Change T-test
Group 18.6 (7.0) 23.6 (7.3) 5.1 (6.2) 0.000
Males 14.8 (4.6) 18.9 (5.1) 4.3 (6.6) 0.022 BODYPUMP™
Females 21.1 (7.2) 26.8 (6.9) 5.5 (6.0) 0.000
Group 15.9 (2.7) 14.5 (5.4) -1.4 (4.2) 0.390
Males 14.4 (1.9) 11.6 (2.4) -2.8 (3.0) 0.108 BODYATTACK™
Females 18.3 (2.1) 19.3 (5.8) 1.0 (5.6) 0.790
Group 15.9 (6.4) 19.2 (4.2) 3.3 (8.6) 0.255
Males 16.3 (8.4) 17.3 (4.6) 1.0 (13.0) 0.906 BODYCOMBAT™
Females 15.7 (6.2) 20.0 (4.0) 4.3 (7.1) 0.162
Group 15.6 (3.1) 16.8 (4.1) 1.2 (4.7) 0.427
Males 15.6 (3.7) 16.1 (4.4) 0.5 (5.3) 0.797 BODYSTEP™
Females 15.7 (1.2) 18.7 (3.2) 3.0 (2.6) 0.188
Group 17.2 (7.4) 15.6 (3.6) -1.5 (5.9) 0.443
Males 13.4 (4.3) 13.2 (2.9) -0.2 (2.6) 0.871 RPM™
Females 22.0 (8.1) 18.5 (1.9) -2.8 (8.2) 0.504
For the group as a whole upper body muscular endurance, as measured by the number of repetitions
performed on the bench press at 70% of 6RM, increased from 17.4 (6.2) reps to 19.5 (6.4) reps. The
BODYPUMP™ group increased from 18.6 (7.0) reps to 23.6 (7.3) reps. Females had higher initial scores
than the males but the level of improvement was similar with males increasing by 4.3 (6.6) reps and
females by 5.5 (6.0) reps. These increases were statistically significant. The BODYATTACK™ group
recorded slight decreases in muscular endurance. Subjects decreased from 15.9 (2.7) reps to 14.5 (5.4)
reps, an decrease of 1.4 (4.2) reps. Male subjects started at a lower number of reps than the females and
© 2007 Les Mills International Limited 39
decreased their number of repetitions. They changed from 14.4 (1.9) to 11.6 (2.4) reps. Females started
from 18.3(2.1) and increases to 19.3 (5.8) reps. The changes in upper body muscular endurance achieved
by BODYATTACK™ males and females were not statistically significant. The BODYCOMBAT™ group
increased from 15.9 (6.4) reps to 19.2 (4.2) reps, an increase of 3.3 (8.6) reps. Males from the
BODYCOMBAT™ group started at 16.3 (8.4) and increased to 17.3 (4.6) reps. The females started at 15.7
(6.2) and increased to 20.0 (4.0). Neither the male or female increase in upper body muscular endurance
was statistically significant. The BODYSTEP™ group recorded small increases in upper body muscular
endurance. The group increased from 15.6 (3.1) reps to 16.8 (4.1) reps, the males increased from 15.6
(3.7) reps to 16.1 (4.4) reps, and the females increased from 15.7 (1.2) reps to 18.7 (3.2) reps. The RPM™
group decreased both as a group and as males and females. The group score decreased from 17.2 (7.4)
reps to 15.6 (3.6) reps, the males decreased from 13.4 (4.3) to 13.2 (2.9) and the females decreased from
22.0 (8.1) to 18.5 (1.9). None of these changes were statistically significant.
Table 13: Change in lower body strength as a result of the intervention
Mean (SD) 6RM leg press (kg)
Pre Post Change T-test
Group 125.7 (45.0) 141.0 (42.4) 15.9 (24.2) 0.000
Males 158.4 (39.1) 167.2 (34.3) 9.4 (31.4) 0.265 BODYPUMP™
Females 103.9 (34.7) 123.6 (38.7) 20.0 (17.9) 0.000
Group 136.9 (39.0) 164.8 (48.2) 27.9 (26.6) 0.021
Males 154.0 (16.7) 184.8 (30.7) 30.8 (31.8) 0.096 BODYATTACK™
Females 108.3 (53.0) 131.3 (59.5) 23.0 (19.9) 0.180
Group 121.8 (43.6) 149.0 (35.4) 27.2 (19.3) 0.002
Males 170.0 (34.6) 186.7 (23.1) 16.7 (11.5) 0.130 BODYCOMBAT™
Females 101.1 (28.2) 132.9 (26.3) 31.7 (20.9) 0.007
Group 136.8 (37.2) 158.2 (39.7) 21.4 (25.9) 0.021
Males 154.4 (25.6) 177.5 (24.9) 23.1 (28.7) 0.056 BODYSTEP™
Females 90.0 (10.0) 106.7 (15.3) 16.7 (20.8) 0.300
Group 157.0 (48.8) 186.0 (50.8) 29.0 (16.0 ) 0.000
Males 196.0 (34.4) 222.0 (49.2) 26.0 (16.7) 0.025 RPM™
Females 118.0 (19.2) 150.0 (12.2) 32.0 (16.4) 0.012
Lower body strength of the whole group as measured using the horizontal leg press, increased from 131.8
(44.1) kg to 150.4 (41.3) kg. The BODYPUMP™ group increased from 125.7 (45.0) kg to 141.0 (42.4) kg.
© 2007 Les Mills International Limited 40
The female BODYPUMP™ group improved their leg press scores to a greater degree than the males.
Females improved from 103.9 (34.7) to 123.6 (38.7), an increase of 20.0 (17.9). Males improved from
158.4(39.1) to 167.2 (34.3), an increase of 9.4 (31.4). Only the increase from the female group was
statistically significant. The BODYATTACK™ group increased from 136.9 (39.0) kg to 164.8 (48.2) kg, an
increase of 27.9 (26.6) kg. Both males and females achieved good increases in the leg press. Females
improved from 108.3 (53.0) to 131.3 (59.5), an increase of 23.0 (19.9). Males improved from 154.0 (16.7) to
184.8 (30.7), an increase of 30.8 (31.8). The increases achieved by BODYATTACK™ males and females
were not statistically significant. The BODYCOMBAT™ group increased from 121.8 (43.6) kg to 149.0
(35.4) kg, an increase of 27.2 (19.3) kg. Females improved from 101.1 (28.2) to 132.9 (26.3), an increase
of 31.7 (20.9). Males improved from 170.0 (34.6) to 186.7 (23.1), an increase of 16.7 (11.5). Only the
increase achieved by the females was statistically significant. The BODYSTEP™ group increased from
136.8 (37.2) kg to 158.2 (39.7) kg, an increase of 21.4 (25.9) kg. Females improved from 90.0 (10.0) to
106.7 (15.3), an increase of 16.7 (20.8). Males improved from 154.4 (25.6) to 177.5 (24.9), an increase of
23.1 (28.7). The increase achieved by the males approached statistical significance. The RPM™ group
increased from 157.0(48.8) kg to 186.0(50.8) kg, an increase of 29.0(16.0) kg. Males and females
improved to a similar degree. . Females improved from 118.0(19.2) to 150.0(12.2), an increase of 32.0
(16.4). Males improved from 196.0 (34.4) to 222.0 (49.2), an increase of 26.0 (16.7). Both the male or
female group increases were statistically significant.
Table 14: Change in lower muscular endurance as a result of the intervention
Mean (SD) number of repetitions of the leg press at 70% of 6RM
Pre Post Change T-test
Group 38.7 (22.4) 43.6 (21.3) 4.3 (9.0) 0.003
Males 39.6 (27.2) 42.9 (25.7) 3.7 (7.3) 0.085 BODYPUMP™
Females 38.1 (19.2) 44.0 (18.4) 4.6 (10.0) 0.015
Group 40.6 (17.5) 42.4 (19.1) 1.8 (7.8) 0.544
Males 34.4 (9.1) 32.8 (8.8) -1.6 (2.7) 0.256 BODYATTACK™
Females 51.0 (25.4) 58.3 (22.5) 7.3 (11.0) 0.370
Group 37.8 (10.2) 45.0 (11.2) 7.2 (11.0) 0.068
Males 37.0 (3.6) 35.7 (4.0) -1.3 (3.5) 0.578 BODYCOMBAT™
Females 38.1 (12.3) 49.0 (11.0) 10.9 (11.2) 0.042
Group 36.7 (15.4) 42.8 (18.4) 6.1 (10.7) 0.088
Males 36.4 (16.8) 42.5 (19.5) 6.1 (10.0) 0.128 BODYSTEP™
Females 37.7 (14.0) 43.7 (18.9) 6.0 (14.8) 0.555
© 2007 Les Mills International Limited 41
Group 36.5 (9.1) 36.7 (12.4) 0.2 (10.7) 0.954
Males 33.6 (7.4) 34.4 (7.9) 0.8 (2.8) 0.554 RPM™
Females 39.4 (10.5) 39.0 (16.4) -0.4 (15.8) 0.958
For the group as a whole lower body muscular endurance, as measured by the number of repetitions
performed on the leg press at 70% of 6RM, increased from 38.7 (23.6) reps to 43.2 (13.0) reps. The
BODYPUMP™ group increased from 38.7 (22.4) reps to 43.6 (21.3) reps. Females increased from 38.1
(19.2) reps to 44.0 (18.4) reps, an increase of 4.6 (10.0) reps. Males increased from 39.6 (27.2) reps to
42.9 (25.7) reps, an increase of 3.7 (7.3) reps. The increase for the female group was statistically
significant. The BODYATTACK™ group increased from 40.6 (17.5) reps to 42.4 (19.1) reps, an increase of
1.8 (7.8) reps. Females increased from 51.0 (25.4) reps to 58.3 (22.5) reps, an increase of 7.3 (11.0) reps.
Males decreased from 34.4 (9.1) reps to 32.8 (8.8) reps, a decrease of 1.6 (2.7) reps. The changes in lower
body muscular endurance achieved by BODYATTACK™ males and females were not statistically
significant. The BODYCOMBAT™ group increased from 37.8 (10.2) reps to 45.0 (11.2) reps, an increase of
7.2 (11.0) reps. Males from the BODYCOMBAT™ group increased from 37.0 (3.6) to 35.7 (4.0) reps. The
females increased from 38.1 (12.3) to 49.0 (11.0). Only the female increase in lower body muscular
endurance was statistically significant. The BODYSTEP™ group recorded an increase in lower body
muscular endurance from 36.7 (15.4) to 42.8 (18.4) reps. The males increased from 36.4 (16.8) reps to
42.5 (19.5) reps, and the females increased from 37.7 (14.0) reps to 43.7 (18.9) reps. None of these
changes were statistically significant. The RPM™ group recorded had similar pre and post measures for
lower body muscular endurance. The group changed from 36.5 (9.1) to 36.7 (12.4) reps. The males
increased from 33.6 (7.4) reps to 34.4 (7.9) reps, and the females decreased slightly from 39.4 (10.5) reps
to 39.0 (16.4) reps. None of these changes in the RPM™ group were statistically significant.
Psychological state as measured by a 20 point questionnaire improved by 10.7 (9.38) points. This reflected
a decrease in negative emotions by 2.54 (4.43) points and an increase in positive emotions by 8.15 (9.66)
points. The BODYPUMP™ subjects increased by 10.9 (8.2) points, from 16.8 (7.8) to 27.0 (7.4).
BODYPUMP™ males increased from 17.0(6.7) to 26.5 (4.6), an increase of 10.7 (8.8) while BODYPUMP™
females increased from 16.6 (8.5) to 27.3 (8.9), a change of 11.0 (8.0). Both the male and female increases
were statistically significant. BODYATTACK™ subjects improved from 15.1 (6.4) to 23.0 (8.7). The
BODYATTACK™ males increased from 17.6 (5.6) to 25.2 (10.2). The BODYATTACK™ females increased
from 11.0 (6.1) to 19.3 (5.0). The female increase was statistically significant. The BODYCOMBAT™ group
increased from 7.8 (6.3) to 20.7 (10.4). ). The BODYCOMBAT™ males increased from 9.7 (3.8) to 21.0
(2.6). The BODYCOMBAT™ females increased from 7.0 (7.3) to 20.6 (12.6). Both the male and female
increases were statistically significant. The BODYSTEP™ group increased from 17.6 (7.0) to 26.5 (6.1).
The BODYSTEP™ males increased from 18.5 (7.7) to 27.3 (7.1). The BODYSTEP™ females increased
from 15.3 (5.0) to 24.7 (2.1). Only the BODYSTEP™ female increase was statistically significant. The
RPM™ group increased from 13.0 (13.1) to 21.3 (8.1). The RPM™ males increased from 16.6 (7.7) to 22.0
© 2007 Les Mills International Limited 42
(5.2). The RPM™ females increased from 9.4 (17.1) to 20.6 (10.9). Only the RPM™ female increase was
statistically significant.
Table 15: Change in psychological state as a result of the intervention
Mean psychological test score
Pre Post Change T-test
Group 16.8 (7.8) 27.0 (7.4) 10.9 (8.2) 0.000
Males 17.0 (6.7) 26.5 (4.6) 10.7 (8.8) 0.000 BODYPUMP™
Females 16.6 (8.5) 27.3 (8.9) 11.0 (8.0) 0.000
Group 15.1 (6.4) 23.0 (8.7) 7.9 (7.8) 0.025
Males 17.6 (5.6) 25.2 (10.2) 7.6 (10.3) 0.173 BODYATTACK™
Females 11.0 (6.1) 19.3 (5.0) 8.3 (2.1) 0.020
Group 7.8 (6.3) 20.7 (10.4) 12.9 (10.1) 0.003
Males 9.7 (3.8) 21.0 (2.6) 11.3 (1.5) 0.006 BODYCOMBAT™
Females 7.0 (7.3) 20.6 (12.6) 13.6 (12.2) 0.026
Group 17.6 (7.0) 26.5 (6.1) 8.9 (4.2) 0.000
Males 18.5 (7.7) 27.3 (7.1) 8.8 (4.4) 0.001 BODYSTEP™
Females 15.3 (5.0) 24.7 (2.1) 9.3 (4.7) 0.076
Group 13.0 (13.1) 21.3 (8.1) 8.3 (7.5) 0.007
Males 16.6 (7.7) 22.0 (5.2) 5.4 (5.3) 0.086 RPM™
Females 9.4 (17.1) 20.6 (10.9) 11.2 (8.8) 0.047
© 2007 Les Mills International Limited 43
Table 16: Combined results for BODYPUMP™
Pre Post Change T-test
Group 176.2 (59.4) 145.3 (50.4) 29.9 (22.9) 0.000
Males 152.3 (47.8) 127.5 (45.3) 23.7 (21.7) 0.000 Sum of 8 skinfolds
(mm)
Females 192.1 (62.0) 157.1 (51.0) 33.8 (23.2) 0.000
Group 41.0 (23.4) 46.0 (26.0) 5.1 (6.8) 0.000
Males 55.3 (23.4) 61.5 (28.5) 6.3 (8.5) 0.009 Beep test level
Females 31.5 (18.2) 35.7 (18.5) 4.3 (5.6) 0.001
Group 33.0 (14.8) 38.1 (15.0) 5.2 (5.4) 0.000
Males 47.0 (11.7) 52.8 (10.9) 6.0 (5.8) 0.001 6RM Bench Press
Females 23.6 (7.5 ) 28.4 (7.5) 4.7 (5.3) 0.000
Group 18.6 (7.0) 23.6 (7.3) 5.1 (6.2) 0.000
Males 14.8 (4.6) 18.9 (5.1) 4.3 (6.6) 0.022
Bench Press repetitions at 70% of
6RM
Females 21.1 (7.2) 26.8 (6.9) 5.5 (6.0) 0.000
Group 125.7 (45.0) 141.0 (42.4) 15.9 (24.2) 0.000
Males 158.4 (39.1) 167.2 (34.3) 9.4 (31.4) 0.265 6RM Leg Press
Females 103.9 (34.7) 123.6 (38.7) 20.0 (17.9) 0.000
Group 38.7 (22.4) 43.6 (21.3) 4.3 (9.0) 0.003
Males 39.6 (27.2) 42.9 (25.7) 3.7 (7.3) 0.085
Leg Press repetitions at 70% of
6RM
Females 38.1 (19.2) 44.0 (18.4) 4.6 (10.0) 0.015
Group 16.8 (7.8) 27.0 (7.4) 10.9 (8.2) 0.000
Males 17.0 (6.7) 26.5 (4.6) 10.7 (8.8) 0.000 Psychological score
Females 16.6 (8.5) 27.3 (8.9) 11.0 (8.0) 0.000
© 2007 Les Mills International Limited 44
Table 17: Combined results for BODYATTACK™
Pre Post Change T-test
Group 198.4 (52.7) 167.5 (49.4) 31.0 (34.6) 0.039
Males 189.1 (49.5) 178.6 (56.9) 10.6 (12.7) 0.136 Sum of 8 skinfolds
(mm)
Females 214.0 (65.0) 149.0 (35.4) 65.0 (32.9) 0.048
Group 44.9 (23.6) 58.3 (26.4) 13.4 (8.1) 0.002
Males 50.2 (26.9) 64.9 (27.9) 14.4 (9.1) 0.024 Beep test level
Females 36.0 (17.7) 47.7 (25.0) 11.7 (7.4) 0.111
Group 36.4 (12.5) 45.8 (19.4) 9.4 (8.6) 0.017
Males 43.0 (10.8) 54.0 (18.8) 11.0 (8.8) 0.049 6RM Bench Press
Females 25.3 (4.5) 32.2 (12.7) 6.8 (9.4) 0.340
Group 15.9 (2.7) 14.5 (5.4) -1.4 (4.2) 0.390
Males 14.4 (1.9) 11.6 (2.4) -2.8 (3.0) 0.108
Bench Press repetitions at 70% of
6RM
Females 18.3 (2.1) 19.3 (5.8) 1.0 (5.6) 0.790
Group 121.8 (43.6) 149.0 (35.4) 27.2 (19.3) 0.002
Males 170.0 (34.6) 186.7 (23.1) 16.7 (11.5) 0.130 6RM Leg Press
Females 101.1 (28.2) 132.9 (26.3) 31.7 (20.9) 0.007
Group 40.6 (17.5) 42.4 (19.1) 1.8 (7.8) 0.544
Males 34.4 (9.1) 32.8 (8.8) -1.6 (2.7) 0.256
Leg Press repetitions at 70% of 6RM
Females 51.0 (25.4) 58.3 (22.5) 7.3 (11.0) 0.370
Group 15.1 (6.4) 23.0 (8.7) 7.9 (7.8) 0.025
Males 17.6 (5.6) 25.2 (10.2) 7.6 (10.3) 0.173 Psychological state
Females 11.0 (6.1) 19.3 (5.0) 8.3 (2.1) 0.020
© 2007 Les Mills International Limited 45
Table 18: Combined results for BODYCOMBAT™
Pre Post Change T-test
Group 176.4 (62.0) 153.8 (53.8) 22.6 (23.8) 0.015
Males 122.5 (61.1) 123.2 (61.0) -0.7 (3.9) 0.794 Sum of 8 skinfolds
(mm)
Females 199.4 (49.6) 166.9 (49.3) 32.6 (21.5) 0.007
Group 55.6 (30.6) 66.0 (27.3) 10.4 (8.2) 0.003
Males 86.7 (30.0) 96.0 (23.6) 9.3 (6.4) 0.128 Beep test level
Females 42.3 (20.4) 53.1 (16.9) 10.9 (9.3) 0.022
Group 41.3 (22.4) 46.7 (24.3) 5.4 (10.5) 0.143
Males 68.3 (17.6) 69.2 (20.1) 0.8 (3.8) 0.742 6RM Bench Press
Females 29.7 (11.3) 37.0 (19.7) 7.3 (12.1) 0.163
Group 15.9 (6.4) 19.2 (4.2) 3.3 (8.6) 0.255
Males 16.3 (8.4) 17.3 (4.6) 1.0 (13.0) 0.906 Bench Press
repetitions at 70% of 6RM
Females 15.7 (6.2) 20.0 (4.0) 4.3 (7.1) 0.162
Group 121.8 (43.6) 149.0 (35.4) 27.2 (19.3) 0.002
Males 170.0 (34.6) 186.7 (23.1) 16.7 (11.5) 0.130 6RM Leg Press
Females 101.1 (28.2) 132.9 (26.3) 31.7 (20.9) 0.007
Group 37.8 (10.2) 45.0 (11.2) 7.2 (11.0) 0.068
Males 37.0 (3.6) 35.7 (4.0) -1.3 (3.5) 0.578 Leg Press repetitions
at 70% of 6RM
Females 38.1 (12.3) 49.0 (11.0) 10.9 (11.2) 0.042
Group 7.8 (6.3) 20.7 (10.4) 12.9 (10.1) 0.003
Males 9.7 (3.8) 21.0 (2.6) 11.3 (1.5) 0.006 Psychological state
Females 7.0 (7.3) 20.6 (12.6) 13.6 (12.2) 0.026
© 2007 Les Mills International Limited 46
Table 19: Combined results for BODYSTEP™
Pre Post Change T-test
Group 163.7 (40.8) 154.3 (38.9) 9.4 (26.1) 0.259
Males 159.9 (40.4) 151.4 (39.9) 8.4 (24.6) 0.365 Sum of 8 skinfolds
(mm)
Females 174.0 (48.9) 162.0 (43.4) 12.0 (35.5) 0.618
Group 58.4 (20.8) 72.9 (25.8) 14.5 (10.8) 0.001
Males 63.4 (21.2) 80.1 (24.1) 16.8 (11.1) 0.004 Beep test level
Females 45.0 (14.7) 53.7 (23.3) 8.7 (8.7) 0.228
Group 45.0 (18.8) 50.1 (21.8) 5.1 (5.5) 0.011
Males 53.8 (13.4) 60.2 (15.4) 6.4 (5.0) 0.008 6RM Bench Press
Females 21.7 (3.1) 23.3 (8.5) 1.7 (6.3) 0.693
Group 15.6 (3.1) 16.8 (4.1) 1.2 (4.7) 0.427
Males 15.6 (3.7) 16.1 (4.4) 0.5 (5.3) 0.797 Bench Press
repetitions at 70% of 6RM
Females 15.7 (1.2) 18.7 (3.2) 3.0 (2.6) 0.188
Group 136.8 (37.2) 158.2 (39.7) 21.4 (25.9) 0.021
Males 154.4 (25.6) 177.5 (24.9) 23.1 (28.7) 0.056 6RM Leg Press
Females 90.0 (10.0) 106.7 (15.3) 16.7 (20.8) 0.300
Group 36.7 (15.4) 42.8 (18.4) 6.1 (10.7) 0.088
Males 36.4 (16.8) 42.5 (19.5) 6.1 (10.0) 0.128 Leg Press repetitions
at 70% of 6RM
Females 37.7 (14.0) 43.7 (18.9) 6.0 (14.8) 0.555
Group 17.6 (7.0) 26.5 (6.1) 8.9 (4.2) 0.000
Males 18.5 (7.7) 27.3 (7.1) 8.8 (4.4) 0.001 Psychological state
Females 15.3 (5.0) 24.7 (2.1) 9.3 (4.7) 0.076
© 2007 Les Mills International Limited 47
Table 20: Combined results for RPM™
Pre Post Change T-test
Group 189.2 (62.9) 161.5 (58.9) 27.7 (23.3) 0.005
Males 139.3 (41.2) 127.2 (50.3) 12.1 (16.6) 0.179 Sum of 8 skinfolds
(mm)
Females 239.0 (31.3) 195.7 (48.4) 43.3 (18.3) 0.006
Group 50.2 (27.6) 59.5 (30.2) 9.3 (10.2) 0.018
Males 72.4 (19.0) 84.0 (14.5) 11.6 (11.9) 0.095 Beep test level
Females 28.0 (11.1) 35.0 (18.6) 7.0 (8.9) 0.154
Group 43.3 (21.8) 47.5 (22.0) 3.8 (6.0) 0.079
Males 55.5 (22.4) 59.5 (23.5) 4.0 (6.8) 0.256 6RM Bench Press
Females 28.1 (6.9) 32.5 (3.5) 3.5 (6.0) 0.271
Group 17.2 (7.4) 15.6 (3.6) -1.5 (5.9) 0.443
Males 13.4 (4.3) 13.2 (2.9) -0.2 (2.6) 0.871 Bench Press repetitions
at 70% of 6RM
Females 22.0 (8.1) 18.5 (1.9) -2.8 (8.2) 0.504
Group 157.0 (48.8) 186.0 (50.8) 29.0 (16.0 ) 0.000
Males 196.0 (34.4) 222.0 (49.2) 26.0 (16.7) 0.025 6RM Leg Press
Females 118.0 (19.2) 150.0 (12.2) 32.0 (16.4) 0.012
Group 36.5 (9.1) 36.7 (12.4) 0.2 (10.7) 0.954
Males 33.6 (7.4) 34.4 (7.9) 0.8 (2.8) 0.554 Leg Press repetitions at
70% of 6RM
Females 39.4 (10.5) 39.0 (16.4) -0.4 (15.8) 0.958
Group 13.0 (13.1) 21.3 (8.1) 8.3 (7.5) 0.007
Males 16.6 (7.7) 22.0 (5.2) 5.4 (5.3) 0.086 Psychological state
Females 9.4 (17.1) 20.6 (10.9) 11.2 (8.8) 0.047
Discussion
The purpose of this study was to quantify the physical and psychological response to 13 weeks of group
exercise classes in previously sedentary adults. Subjects performed a battery of fitness tests immediately
prior to and immediately following the 13-week intervention. The intervention consisted of participation in
LES MILLS™ Body Training Systems aerobics classes, specifically; BODYPUMP™, BODYATTACK™,
BODYSTEP™, BODYCOMBAT™ and RPM™. Seventy-nine subjects finished the 13 weeks and satisfied
the criteria for inclusion in the study. The distribution of subjects is shown below (Refer to Table 21).
© 2007 Les Mills International Limited 48
Table 21: Distribution of subjects who finished the study
Group Males Females
BODYPUMP™ 40 16 24
BODYATTACK™ 8 5 3
BODYCOMBAT™ 10 3 7
BODYSTEP™ 11 8 3
RPM™ 10 5 5
TOTAL 79 37 42
Body Composition
A strategy to modify body composition typically involves both dietary modification and an exercise
intervention. This study used only an exercise intervention. The average decrease in percent body fat of all
the subjects was 2.1% (a decrease in skinfolds of 21mm). The subjects who performed BODYPUMP™ had
the largest decrease in percent body fat (2.7%) with similar decreases for the men and women in the
group. This is despite a lower caloric demand of the BODYPUMP™ class in comparison to
BODYATTACK™, BODYSTEP™, BODYCOMBAT™ and RPM™ (Refer to Table 22).
Table 22: Caloric demand of Les Mills Body Training System (LMBTS) classes [1, 7]
Class Duration (mins)
Total Calories used in class
Cal per min of class
Total Cal per 75 kg of bodyweight
BODYSTEP™
Average (SD) 54.5 555.6 (64.8) 10.2 (1.1) 575.6 (95.6)
BODYATTACK™
Average (SD) 57.0 631.0 (103.2) 11.1 (1.8) 700.0 (64.7)
BODYCOMBAT™
Average (SD) 44.7 462.8 (82.2) 10.4 (1.8) 509.8 (44.0)
RPM™
Average (SD) 45.3 582.1 (92.8) 12.8 (1.9) 636.6 (56.1)
BODYPUMP™
Average (SD) 57.0 411.0 (99.3) 7.2 (1.6) 433.6 (99.3)
The fact that the BODYPUMP™ subjects had the largest reduction in body fat despite a lower acute caloric
expenditure, suggests that resting metabolic rate was increased as a result of the muscular activity of the
class. This would have the effect of increasing daily caloric expenditure and may help explain the decrease
in body fat reported. The size of the sample and the high level of statistical significance strengthen the
merits of this suggestion. The female subjects in the RPM™ group also recorded a large decrease in
© 2007 Les Mills International Limited 49
percent body fat (3.3%). This group, however, started from a level of body fat that was substantially higher
than the males in the RPM™ group and the females in other groups. This higher level of body fat
moderates the larger reduction over the 13 weeks. The males in the BODYCOMBAT™ group had a similar
situation, reporting no reduction in body fat over the 13 weeks. Closer inspection of this result shows that
there were only three subjects and that they were initially very lean (they had the lowest level of body fat of
any group at the commencement of the study). The reductions in body fat for all subjects were reasonably
consistent. The addition of a controlled caloric intake would most likely result in greater reductions in body
fat.
Aerobic Fitness
The multi-stage fitness test (beep test) is a very simple way to measure aerobic fitness. It provides the ideal
test to assess the fitness of large groups of people such as the sample used in this study. The table in
appendix 2 shows the approximation to VO2 max from each level in the beep test (please refer to
Appendix). The BODYPUMP™ group had small increases in their beep test scores which reflects the
nature of the class. ie it has a muscular focus as opposed to an aerobic focus. All the other classes had
more sizeable increases in their beep test scores. BODYATTACK™ and BODYSTEP™ had the largest
increases in beep test score, which reflects their aerobic focus. This is supported by a previous study
performed by the same author reported high aerobic intensities for these classes[1]
. The beep test is not
without criticism as a measure of aerobic fitness. It requires the ability to run and change direction every
20m. It is possible that some subjects were unable to perform this test to the best of their ability because of
their perceived inability to run and change direction quickly. This was illustrated by some subjects recording
the same or a lower result on the second test (after 13 weeks of exercise). Had an alternative test been
used to measure aerobic fitness the improvements achieved may have been higher.
Upper Body Strength
The bench press is one of the most fundamental strength training exercises. Its movements closely
resemble the basic pushup, which is likely to have been performed by every person at some stage of their
life. Performing the bench press using free weights (a barbell and weights) is more challenging than using a
machine as it requires a degree of balance and coordination. To overcome this technical prerequisite, all
subjects were given basic instruction in the exercise prior to performing the test. All groups reported
improvements in their 6RM bench press ranging from 3.8 to 9.4 kg. Some of the classes do not specifically
address upper body strength and as a consequence were unlikely to result in anything more than small
changes in upper body strength. However, other classes, such as BODYPUMP™, do provide a
comprehensive upper body muscular workout. The modest increases in upper body strength in the
BODYPUMP™ group suggest that the training variables of the class (repetitions, load, rests etc) do not
specifically promote an increase in 6RM strength.[8]
© 2007 Les Mills International Limited 50
Upper Body Muscular Endurance
Upper body muscular endurance was assessed with the subjects performing as many repetitions as
possible of the bench press using 70% of their 6RM load. The load that was used for the muscle endurance
test was not the same for both tests. Consequently, if a subject’s 6RM load increased from test 1 to test 2
so did their muscle endurance load. As a result of this there were some decreases in muscle endurance
shown (by the BODYATTACK™ group and the RPM™ group). The BODYPUMP™ group demonstrated
the largest change in upper body muscular endurance with an average increase of 5.1 repetitions or
27.5%. This indicates that the training variables of the class do specifically promote an increase in upper
body muscular endurance. Motivation is a key component in this particular test. Some subjects reported
that despite feeling stronger and in better condition than at the start of the study, they were unable to
perform as many repetitions as the first test due to a lack of motivation and concentration.
Lower Body Strength
Lower body strength was measured using a pin-loaded horizontal leg press. The subject’s 6RM was
measured. All groups reported increases on this test with an average increase of 18.6 kg. All classes
involve considerable lower body activity. BODYPUMP™ involves specific strength training exercises such
as weighted Squats and Lunges. BODYSTEP™ incorporates bench-stepping movements and RPM™ uses
slower cadences and a higher fly-wheel resistance to promote strength increases. BODYATTACK™ and
BODYCOMBAT™ do not use a specific tool or apparatus but incorporate large amounts of lower body
calisthenic movements. The high level of statistical significance for most of the groups suggests that
regardless of the class chosen, a novice participant undertaking a Les Mills International franchised
program will receive an improvement in lower body strength.
Lower Body Muscular Endurance
Lower body muscular endurance was assessed with the subjects performing as many repetitions as
possible of the leg press using 70% of their 6RM load. In contrast to the large increase in leg press 6RM
strength, the increases in lower body muscular endurance were relatively modest. Because the 6RM
scores increased significantly, the loads used for the muscle endurance test also increased significantly.
This offers some explanation for the lower scores. For all subjects the number of repetitions performed
before failure still increased by 4.5 repetitions, representing a 12% increase in muscular endurance.
However, in contrast to the 6RM leg press results, the level of statistical significance was not high enough
to conclusively indicate an effect.
Psychological Well-being
Questionnaires are the common method of non-clinical psychological assessment. The questionnaire used
in this study was selected because it contained a balanced assessment of both positive and negative
emotions and consequently documented improvements in positive emotions as well as the typical decrease
in negative emotions as a result of an exercise program. The result was a clear and significant increase in
© 2007 Les Mills International Limited 51
the psychological well-being of the subjects. The positive emotions changed to a larger degree than the
negative emotions. Indeed, the 10.7-point change in the emotional index was made up from a 2.5 point
reduction in negative emotions and an 8.2 increase in positive emotions. Subjects reported marked
improvements in emotional strength, and feelings of alertness and pride. They also felt more inspired and
active.
Subject Adherence
Dropout rate is always a major concern of studies involving untrained subjects in an exercise program. The
dropout rate in this study was 47.3% which is lower than typically expected for a study such as this. This
suggests that the nature of the program improved the rate of retention of subjects.
Limitations
The level of adaptation that occurs in response to a stimulus is dependent largely on the intensity of that
stimulus. As the subjects did not have the intensity of their sessions monitored, there was no way of
determining whether the individual intensities selected were sufficient to result in any significant adaptation.
During the fitness testing sessions it became apparent that some subjects were prepared to exert
themselves maximally and work at a high intensity while others were not so willing. A study that ensured an
appropriate and consistent intensity during both testing and exercise sessions would be likely to
demonstrate significantly larger increases in physical fitness than those reported in this study.
The sample size in some of the groups did not allow for statistical significance to be reached. This was
particularly reflected when males and females were considered separately. BODYSTEP™ females,
BODYATTACK™ females and BODYCOMBAT™ males only had three subjects in the group. Greater
numbers in these groups would have provided a greater insight into their longitudinal effect on untrained
subjects.
Conclusion
The results of this study show that untrained subjects can achieve significant improvements in physical
fitness and psychological well-being through participation in 13 weeks of BODYPUMP™,
BODYATTACK™, BODYSTEP™, BODYCOMBAT™ or RPM™ group exercise sessions. As the exercise
variables are different between the classes, so too are the specific adaptations received after long term
participation but there are nonetheless general positive changes in body composition, aerobic fitness,
upper and lower body strength and muscular endurance and psychological well-being. The lack of a
prescribed and monitored exercise intensity may have resulted in improvements in fitness and
psychological well-being that did not accurately reflect the demands of each of the classes which as
determined in a previous study was substantial. Further research should attempt to control exercise
intensity and should also ensure that sufficient numbers of subjects are present in all groups.
© 2007 Les Mills International Limited 52
references
1. Lythe J and Pfitzinger P. (1999). Caloric expenditure and aerobic demand of BODYSTEP™,
BODYATTACK™, BODYCOMBAT™ and RPM™. Auckland: UniSports, University of Auckland:15.
2. Durnin J V and Womersley J.(1974). Body fat assessed from total body density and its estimation
from skinfold thickness: measurements on 481 men and women aged 16 to 72 years. British Journal of
Nutrition; 32:77-97.
3. Siri W E. (1961). Body composition from fluid spaces and density: analysis of methods. In: Brozek
J and Henschel A, eds. Techniques for Measuring Body Composition. Washington DC: National Academy
of Sciences: 223-244.
4. Heyward V H. (1996). Evaluation of body composition. Sports Medicine;22(3): 146-156.
5. Knutzen K M, Brilla L R and Caine D. (1999). Validity of 1RM prediction equations for older adults.
Journal of Strength and Conditioning Research; 13(3):242-246.
6. Abadie B R, Altorfer G L and Schuler P B. (1999). Does a regression equation to predict maximum
strength in untrained lifters remain valid when the subjects are technique trained? Journal of Strength and
Conditioning Research; 13(3):259-263.
7. Stanforth D, Stanforth P and Hoemeke M. (2000). Physiologic and metabolic responses to a
BODYPUMP™ workout. Journal of Strength and Conditioning Research; 14(2):144-150.
8. Tan B. (1999). Manipulating resistance-training program variables to optimize maximum strength in
men: A review. Journal of Strength and Conditioning Research; 13(3):289-304.
© 2007 Les Mills International Limited 53
Appendix A
Table 23: Relationship of Repetitions to 1RM
Repetitions Percentage of 1RM
1 100.0
2 93.5
3 91.0
4 88.5
5 86.0
6 83.5
7 81.0
8 78.5
9 76.0
10 73.5
© 2007 Les Mills International Limited 54
Appendix b
PSYCHOLOGICAL QUESTIONNAIRE PANAS – Form WC1
NAME_____________________________________________________________________
SIGNED_______________________________________________DATE_______________
INSTRUCTIONS:
Below is a list of words that describe feelings people have. We are interested in how participation in
Les Mills’ group exercise classes affects your positive and negative mood states. Please read each word
and then CIRCLE THE NUMBER THAT BEST DESCRIBES HOW YOU HAVE FELT IN THE LAST
WEEK.
Not at all A little Moderately Quite a bit Extremely
(0) (1) (2) (3) (4)
Interested 0 1 2 3 4
Distressed 0 1 2 3 4
Excited 0 1 2 3 4
Upset 0 1 2 3 4
Strong 0 1 2 3 4
Guilty 0 1 2 3 4
Scared 0 1 2 3 4
Hostile 0 1 2 3 4
Enthusiastic 0 1 2 3 4
Proud 0 1 2 3 4
Irritable 0 1 2 3 4
Alert 0 1 2 3 4
Ashamed 0 1 2 3 4
Inspired 0 1 2 3 4
Nervous 0 1 2 3 4
Determined 0 1 2 3 4
Attentive 0 1 2 3 4
Jittery 0 1 2 3 4
Active 0 1 2 3 4
Afraid 0 1 2 3 4
Thank you for completing this form
© 2007 Les Mills International Limited 55
Appendix c
Table 24: Relationship of beep test score to VO2 max
Beep Level
VO2 max Beep Level
VO2 max Beep Level
VO2 max Beep Level VO2 max
24 26.4 54 37.4 84 47.1 114 56.0
25 26.8 55 37.8 85 47.4 115 56.2
26 27.2 56 38.1 86 47.7 116 56.5
27 27.6 57 38.5 87 48.0 117 56.8
28 27.9 58 38.8 88 48.3 118 57.1
29 28.3 59 39.2 89 48.7 119 57.3
30 28.7 60 39.5 90 49.0 120 57.6
31 29.1 61 39.9 91 49.3
32 29.5 62 40.2 92 49.6
33 29.8 63 40.5 93 49.9
34 30.2 64 40.8 94 50.2
35 30.6 65 41.1 95 50.5
36 31.0 66 41.4 96 50.8
37 31.4 67 41.8 97 51.1
38 31.8 68 42.1 98 51.4
39 32.2 69 42.4 99 51.7
40 32.6 70 42.7 100 51.9
41 32.9 71 43.0 101 52.2
42 33.3 72 43.3 102 52.5
43 33.6 73 43.6 103 52.8
44 33.9 74 43.9 104 53.1
45 34.3 75 44.2 105 53.4
46 34.6 76 44.5 106 53.7
47 35.0 77 44.8 107 54.0
48 35.3 78 45.2 108 54.3
49 35.7 79 45.5 109 54.5
50 36.0 80 45.8 110 54.8
51 36.4 81 46.1 111 55.1
52 36.7 82 46.4 112 55.4
53 37.1 83 46.8 113 55.7
© 2007 Les Mills International Limited 56
THE PHYSICAL AND PSYCHOLOGICAL RESPONSE TO 18 WEEKS OF
BODYPUMP IN UNTRAINED INDIVIDUALS
LYTHE J, PFITZINGER, P & HO D. UNISPORTS CENTER FOR SPORT PERFORMANCE, UNIVERSITY OF AUCKLAND (2000)
INTRODUCTION
At the conclusion of the 13-week exercise program discussed in the above report, a group of subjects
performing the BODYPUMP™ class were asked to continue for a further five weeks. The primary purpose
of this five-week extension was to investigate the relative physical and psychological changes occurring in
the first 13 weeks compared to the following five weeks, particularly in body composition.
METHODS
Fifteen subjects were asked to perform the extra five weeks. The same class frequency conditions applied
as during the first 13 weeks, ie to complete between two and five sessions per week. Subjects were then
tested in an identical manner to the week 1 and week 14 tests. All subjects were tested within seven days
of finishing their final week of exercise.
RESULTS
Eleven (6 males, 5 females) subjects completed the extra five weeks and were fitness tested. The results
for all tests are shown in below (Table 1).
© 2007 Les Mills International Limited 57
Table 1: Results for BODYPUMP™ subjects for all tests performed at weeks 1, 14 and 19.
Test Parameter
Group Test 1 Test 2 Test 3 T-test 1-2*
T-test 1-3*
T-test 2-3*
All Subjects 37.7 (14.9) 39.9 (19.1) 42.3 (21.4) 0.33 0.11 0.36
Males 46.8 (12.1) 49.3 (19.2) 52.7 (22.5) 0.50 0.28 0.42 Beep Test
Females 26.8 (10.0) 28.6 (12.7) 29.8 (12.5) 0.53 0.11 0.74
All Subjects 185.9 (45.5) 156.1(35.3) 161.8 (44.0) 0.00 0.00 0.25
Males 171.7 (40.0) 156.6 (27.3) 152.8 (34.7) 0.07 0.01 0.5 Skinfolds
(mm)
Females 202.9 (50.2) 155.5 (46.7) 162.7 (55.4) 0.00 0.01 0.02
All Subjects 32.8 (4.1) 30.1 (4.9) 30.6 (5.4) 0.01 0.01 0.39
Males 30.4 (3.3) 27.8 (3.0) 27.5 (3.9) 0.07 0.03 0.74 Percent Body
fat
Females 35.8 (3.0) 32.9 (5.5) 33.4 (4.7) 0.07 0.16 0.04
All Subjects 35.2 (15.2) 41.5 (16.0) 44.8 (16.9) 0.00 0.00 0.05
Males 47.1 (8.6) 54.4 (7.7) 58.3 (7.0) 0.01 0.01 0.11 6RM Bench
Press
Females 21.0 (4.6) 25.9 (3.5) 28.5 (6.8) 0.03 0.00 0.32
All Subjects 19.1 (6.6) 23.0 (7.8) 20.0 (4.6) 0.06 0.61 0.19
Males 15.7 (5.3) 19.7 (6.0) 17.8 (4.3) 0.21 0.35 0.43
Upper Body Muscular
Endurance Females 23.2 (5.9) 27.0 (8.4) 22.6 (3.9) 0.24 0.85 0.35
All Subjects 131.7 (56.1) 150.4 (46.9) 165.5 (66.9) 0.04 0.02 0.09
Males 166.5 (48.2) 185.0 (25.1) 208.3 (52.6) 0.26 0.11 0.13 6RM Leg
Press
Females 90.0 (31.4) 108.8 (27.5) 114.0 (40.8) 0.03 0.06 0.51
All Subjects 45.0 (30.8) 49.2 (28.0) 30.3 (7.9) 0.11 0.19 0.08
Males 37.5 (34.3) 42.2 (29.6) 28.7 (7.8) 0.13 0.62 0.40
Lower Body Muscular
Endurance Females 54.0 (26.7) 57.6 (26.5) 32.2 (8.3) 0.47 0.17 0.12
All Subjects 17.2 (6.7) 26.4 (5.6) 26.1 (5.0) 0.00 0.00 0.81
Males 19.3 (7.2) 26.3 (2.8) 26.3 (2.9) 0.04 0.03 1.00 Psychological
Score
Females 14.6 (5.7) 26.4 (8.3) 25.8 (7.2) 0.04 0.07 0.79
*T-test 1-2 indicates statistical significance from test 1 to test 2
*T-test 1-3 indicates statistical significance from test 1 to test 3
*T-test 2-3 indicates statistical significance from test 2 to test 3
© 2007 Les Mills International Limited 58
Discussion
The beep test score improved from week 1 to week 14 and again to week 19. This trend was shown when
the group was considered as a whole and when males and females were considered separately. However
these changes had low statistical significance. The rate of improvement in the beep test was not consistent,
the males increased at a greater rate from week 14 to week 19 than they did from week 1 to week 14;
whereas the females had a linear increase (similar per-week improvements in both periods).
Body fatness showed a considerable and significant decrease from week 1 to week 14 but little or no
decrease from week 14 to week 19. Both sum of eight skinfolds and percent body fat displayed this trend.
This suggests that the either the extra five weeks of BODYPUMP™ did not create a daily caloric deficit
sufficient to decrease body fatness or that the effects of the extra five weeks have not yet materialized.
The values for 6RM bench press increased from week 1 to week 14 and continued to increase from week
14 to week 19. All groups displayed this result (total subjects, males only, females only). The improvements
were relatively linear in that the increases attributable to the extra five weeks were approximately half the
increases attributable the first 13 weeks (similar per-week increase as shown in Figure 2). The results for
upper body muscular endurance decreased. A similar effect was seen for subjects performing the other
classes over the 13 weeks. This may be due to the fact that motivation was not as great as it was during
the first tests and that a small sample size did not accurately reflect the effects of the class.
Leg strength improved from week 1 to week 14 and continued to increase from week 14 to week 19.
Females showed a decreased rate of improvement in the second block of five weeks as compared to the
first block of 13 weeks while the males improved at a greater rate during second block of five weeks. The
increases from week 14 to week 19 were not statistically significant. Lower body muscular endurance
increased from week 1 to week 14 but decreased for all groups from week 14 to week 19. This result is
similar to upper body muscular endurance and may reflect a lower level of motivation and a higher absolute
load being used for the muscular endurance test.
Psychological score increased from week 1 to week 14 but remained relatively constant between weeks 14
and 19. This indicates that the improvements in psychological and emotional wellbeing had been achieved
in the first 13 weeks of exercise and that this improved state of mental health was maintained through
continued participation.
CONCLUSIONS
The purpose of extending the 13-week study for an extra five weeks was to identify the relative changes
occurring in physical and psychological parameters in the first block of exercise (13 weeks) vs the second
block of exercise (five weeks). The results indicate that 6RM strength continued to improve in both the
bench press and the leg press exercise. Beep test scores also continued to improve. All other test
© 2007 Les Mills International Limited 59
parameters (body fatness, upper body muscular endurance, lower-body muscular endurance, and
psychological state) either remained the same or decreased.
As the sample size was relatively small for the final five weeks of the study there was moderate to low
statistical significance for the changes that occurred between week 14 and week 19. Future research would
benefit from a greater sample size.
© 2007 Les Mills International Limited 60
EXCESS POST-EXERCISE OXYGEN CONSUMPTION FOLLOWING
BODYPUMPTM
LYTHE J
UNISPORTS CENTER FOR SPORT PERFORMANCE, UNIVERSITY OF AUCKLAND (2001)
INTRODUCTION
Maintaining the appropriate balance between caloric intake and caloric expenditure for the purposes of
weight maintenance or weight loss requires accurate information regarding caloric composition of food that
is eaten and the caloric cost of daily activities. Exercise sessions are used as an effective means of
increasing caloric expenditure. The caloric cost of exercise can be determined by directly measuring (or
estimating) energy expenditure during the exercise session. In addition to the calories that are expended
during the session, there are additional calories expended during the post-exercise period that are directly
attributable to the exercise. These additional calories used to be referred to as the oxygen debt but are now
known as the excess post-exercise oxygen consumption (EPOC) and are consumed by the body to assist
with the various processes involved with recovery. Excess post exercise oxygen consumption (EPOC) is
© 2007 Les Mills International Limited 61
defined as the energy expended in addition to the normal resting metabolic rate as a result of performing
an exercise session.[24]
EPOC
Although the physiological processes that contribute to EPOC have not been clearly defined, potential
factors affecting post-exercise recovery include elevated body temperature, phosphogen resynthesis, re-
synthesis of glycogen from lactate, re-saturation of tissue water, re-saturation of venous blood, re-
saturation of blood in skeletal muscle, re-saturation of myoglobin, redistribution of ions within tissue
compartments, tissue repair, residual effects of hormones and substrate recycling[5,6]
.
To quantify EPOC it is first necessary to determine a person’s resting metabolic rate (RMR). This is defined
as the amount of calories consumed and oxygen used by an individual per minute when at rest. It can only
be measured after an overnight fast of approximately 12 hours (to avoid the thermic effect of a meal) and
when the subject has refrained from strenuous exercise for approximately 24 hours. RMR is the energy
required to sustain essential body processes such as respiration, brain function and cardiac function.
A typical bout of aerobic exercise results in a metabolic elevation that lasts approximately 30 minutes.
Although more prolonged (three hours) or high-intensity (above the anaerobic threshold) activities may
cause a greater increase in caloric expenditure, previous studies suggest that intensity of training may have
a somewhat greater effect upon recovery energy expenditure than duration[5,6]
. Weight training is a
commonly used form of high-intensity anaerobic training among athletes and the general public. Studies of
weight training indicate that hormonal perturbations, particularly for catecholamin, cortisol and growth
hormone, can be substantial. This is especially the case if repetitions per set are high (10-12) and the rest
periods between sets are short (30-60 seconds)[5]
.
Previous research has measured EPOC following a number of different exercise sessions. A review of
these studies is presented below (Table 1).
Table 1: Summary of EPOC studies
Reference Activity EPOC
Almuzaini (1998) 30 minutes of continuous cycling vs 2 x 15 minutes of cycling with 6 hours in between sessions
2 x 15 minutes = 37.5 kcal
1 x 30 minutes = 26.7 kcal
Burleson (1998) 27 minutes of treadmill running vs 16 sets of weight-training exercises performed in a circuit fashion
Running = 64 kcal
Weight training = 95kcal
Gore (1990)
Treadmill running for 20, 50 and 80 minutes at 50% and 70% of VO2 max
50% VO2 max/20 mins = 16 kcal
50% VO2 max/50 mins = 27kcal
50% VO2 max/80 mins = 31 kcal
70% VO2 max/20 mins = 28 kcal
70% VO2 max/50 mins = 50kcal
© 2007 Les Mills International Limited 62
70% VO2 max/80 mins = 72 kcal
Elliot (1992)
40 minutes of cycling at 70% maximum heart rate vs circuit training (8 exercises, 4 sets of 15 reps at 50% 1RM with 30 seconds, rest between sets) and resistance training (8 exercises for 3 sets of 3-8 reps at 90% of 1RM with 90 seconds, rest between sets)
Cycling = 32 ± 16
Circuit = 48 ± 20
Heavy lifting = 51 ± 31
Haltom(1999)
Circuit training using 2 sets of 8 exercises. 20 reps at 75% of 20RM load. Rest intervals were either 20 seconds or 60 seconds
20seconds = 51.5kcal
60seconds = 37kcal
Imamura (1999) 70 minutes of standard Karate training 9.3± 7.7kcal
Melby, C L (1992) 42 minutes of weight training. 14 sets at 12 RM with 60-90 seconds, rest between sets
19 kcal
Murphy (1992) Set-rest and circuit-style resistance training using the same 6 large muscle group exercises
Circuit training = 24.9 kcal
Set-Rest = 13.5 kcal
Quinn (1994) Treadmill walking of 20, 40 and 60 minutes at 70% of VO2 max
20 minutes = 46.3 kcal
40 minutes = 59.6 kcal
60 minutes = 89.2 kcal
Sedlock (1991) 20 minutes of exercise on cycle vs arm crank ergometer at 60% of mode-specific VO2 max
Arm = 9.2 kcal
Cycle = 10.4 kcal
Sedlock (1992) 30 minutes of treadmill or cycle at 60-65% of mode-specific VO2 max
Cycling = 15 kcal
Treadmill = 17 kcal
Sedlock (1993) 30 minutes of cycling at 60% of VO2 peak
Women = 9.4 ± 4.7 kcal
Men = 13 ± 4.6 kcal
Short (1996) Arm ergometry at high (70% VO2 peak for 15 minutes) and low intensity (35% VO2 peak for 30 minutes)
High intensity = 7.8 kcal
Low intensity = 3.0 kcal
Ziegenfuss (1992) Intermittent cycling (2 minutes at 45% VO2 max: 2 minutes at 90% VO2 max) and continuous cycling (47 minutes)
38 ± 7 kcal for intermittent activity
27 ± 10 for continuous activity
© 2007 Les Mills International Limited 63
BODYPUMP
BODYPUMP™ is a group-exercise aerobics program that is part of the LES MILLS™ Body Training
Systems package. BODYPUMP™ is designed to provide a full-body workout to improve body composition
and increase muscular endurance. The class consists of 10 tracks (including a designated warmup and
cool down) of four to six minutes each, targeting specific body parts. Each track consists of a variety of
exercises and variations that overload a specific muscle or muscle group. Various published and
unpublished research has previously been conducted on BODYPUMP™. Pfitzinger et al (1999) measured
aerobic intensity and caloric consumption during BODYPUMP™ in 12 experienced (6 male and 6 female)
subjects. A similar study was conducted by Stanforth et al. (2000). This study used 30 inexperienced (15
male and 15 female) subjects. A comparison between the two studies is presented in Table 2below
Table 2: The aerobic demand of BODYPUMP™
Variable Stanforth Pfitzinger et al (1999)
Average VO2 (ml/kg/min) 14.8 ± 1.3 20.2 ± 3.6
Average % of VO2 max/peak 29.1 ± 3.4 40.7 ± 5.3
Average Heart Rate (bpm) 123.6 ± 18.7 135.4 ± 12.8
Average % of HR max 63.0 ± 8.7 74.2 ± 4.7
Total Calorie Consumption (kcal) 265 ± 60 411.0 ± 99.3
The differences in caloric consumption and aerobic demand between the two studies may be explained by
the fact that subjects used by Stanforth had higher levels of aerobic fitness and used significantly lower
loads during the BODYPUMP™ class.
Lythe et al. (2000) measured the change in physical and psychological fitness in 40 previously sedentary
adults over 13 weeks of BODYPUMP™ at a frequency of three sessions per week. A summary of results is
presented in Table 2 below.
As yet, no study has investigated the EPOC associated with BODYPUMP™. The purpose of this study was
to measure the excess post-exercise oxygen consumption in 12 male subjects following a BODYPUMP™
session. Additional information would be gained about heart rates and typical loading used by experienced
participants during BODYPUMP™
© 2007 Les Mills International Limited 64
Table 3: Response to 13 weeks of BODYPUMP™ in untrained individuals
Variable Increase/Decrease Change
Sum of 8 skinfolds (mm) Decrease 29.9 (22.9)*
Body Fat (%) Decrease 2.7 (2.0)*
Multi stage Fitness Test Level Increase 5.1 (6.8)*
6RM Bench Press Increase 5.2 (5.4)*
Upper Body Muscular Endurance (repetitions of a bench press at 70% 6RM)
Increase 5.1 (6.2)*
6RM Leg Press Increase 15.9 (24.2)*
Lower Body Muscular Endurance (repetitions of a bench press at 70% 6RM)
Increase 4.3 (9.0)*
Psychological Wellness Increase 10.7 (8.8)*
* Indicates statistical significance at 0.05 level
METHODS
Subjects
Twelve male subjects volunteered to participate in the study. Their physical characteristics are presented
below (In Table 4). Five subjects were very experienced with BODYPUMP™, being either instructors or
regular participants, while seven subjects, although physically fit and active, were not regular participants of
BODYPUMP™. All subjects provided written consent to participate in the study.
Table 4: Subject characteristics
Variable Mean (SD)
Age (years) 31.9 (4.9)
Weight (kg) 80.8 (5.6)
Height (cm) 176.7 (4.8)
Subjects were required to attend two testing sessions, one for determination of body composition and
maximal oxygen consumption and the second for performance of BODYPUMP™ and measurement of
RMR and EPOC.
Body Composition
A body composition assessment was conducted because previous research had identified that resting
metabolic rate correlates most closely with fat-free body mass.6] The subject was weighed wearing minimal
clothing to the nearest 0.1 kg using Seca Alpha digital scales. Height was measured to the nearest 0.1 cm
using a stadiometer. Skinfold measurements were taken in accordance with ISAK (International Society for
the Advancement of Kinanthropometry) procedures. Surface markings were made from anatomical
landmarks and skinfold thicknesses were taken in duplicate using Harpenden calipers from the following
© 2007 Les Mills International Limited 65
sites, triceps, subscapular, biceps, iliac crest, supraspinale, abdominal, front thigh and medial calf. The two
measurements taken at each site were averaged to give a value for that site. If the two values differed by
more than 2mm, a third measurement was taken and the median of the three measures was used as the
value for that site.
Percent Body Fat Calculation
A number of formulae exist to estimate percent body fat from skinfold and other anthropometric
measurements. Some of these formulae are age, gender and population specific while others are very
general. The formula used to generate body density for this study was that of Withers et al (1987). This
equation uses seven sites and was developed on a specific population (athletic males aged 18-37) and
was considered appropriate for this group of subjects. Percent body fat was then calculated using the
average of formulae of Siri and Brozek (1961).
Body Density = 1.0988 – 0.0004 (sum of triceps, sub-scapular, biceps, supraspinale, abdominal,
thigh and calf).
Percent Body Fat = average of:
((4.95/Body Density)-4.50)*100; and
((4.57/Body Density)-4.142)*100
VO2 max
Maximal oxygen consumption was measured during a graded exercise test on a treadmill. Subjects were
familiarized to the Powerjog treadmill during a 5-10 minute warmup period. During this time the speed of
the treadmill was varied in an effort to find a speed at which the subject was comfortable running. For all
subjects this fell between 10 km/h and 13 km/h. After this warmup period the subject was allowed to leave
the treadmill and perform self-selected stretching exercises. When ready, the subject returned to the
treadmill. They were fitted with a Polar Accurex heart rate monitor (chest strap and receiver) with the
receiver set to record heart rate every five seconds. Subjects were also fitted with a mask system to allow
for the collection of expired gasses. The subjects breathed through a Hans Rudolph mouthpiece connected
to a Hans Rudolph, two-way, non-rebreathing valve (Kansas City, MO), and wore a nose clip. Inspired air
was measured using a K520 flow transducer (KL Engineering, Sylmar, CA). Expired gases were
continuously sampled and averaged every 30 seconds from a 5-liter mixing chamber and analyzed using
Ametek S-3 A1 oxygen and CD-3A carbon dioxide analysers. Prior to each test, the oxygen and CO2
analyzers were calibrated using a gas mixture of known concentration. The analyzers and flow transducer
were interfaced through an 8-bit A/D converter to an IBM-compatible computer. Ventilation, oxygen
consumption, CO2 production, and respiratory exchange ratio were calculated and displayed using Ametek
OCM-2 Oxygen Uptake System software.
© 2007 Les Mills International Limited 66
The VO2 max test was a continuous, step protocol. The speed of the treadmill was held constant with the
gradient of the treadmill increasing 1% per minute. Subjects continued until volitional exhaustion. To
represent VO2 max, all subjects achieved the following criteria: 1) attainment of a heart rate within 10 beats
per minute of age-predicted maximum (using the equation 220 minus age in years); 2) a plateau in oxygen
uptake despite an increase in work-rate, and 3) a respiratory exchange ratio of 1.10 or greater. If two of the
three criteria were met then the highest (30-second average) VO2 recorded was taken as the subjects VO2
max. Subjects who failed to meet two of these criteria were re-tested within three to five days. Maximal
heart rate was downloaded from the Polar receiver. Within two minutes of completion of the test a blood
sample was taken from the fingertip and analyzed for levels of blood lactate using a YSI 1500 sport lactate
analyzer.
EPOC Session
Resting Metabolic Rate
Subjects arrived at the laboratory at 6:30am after a 12-hour fast and having refrained from strenuous
exercise for at least 24 hours. Subjects underwent 45 minutes of seated rest in a comfortable environment.
Gas analysis was used (with the same procedures as during the VO2 max test) during the last 15 minutes
of this period for determination of resting metabolic rate. Heart rates were also collected every 60 seconds
during this period and a blood lactate sample was taken from the fingertip at the conclusion of the 45
minutes. Oxygen consumption values were converted to energy equivalents ranging from 4.851-5.189 kcal
per liter of oxygen using the updated non-protein calculations of Peronnet and Massicotte (1991).
BODYPUMP™
Subjects then performed a BODYPUMP™ aerobics class by following the instruction from a video
recording (BODYPUMP™ Release 37). In addition to the video recording a BODYPUMP™ instructor was
present to monitor the subject and provide assistance. The class was performed in a well-ventilated space
and subjects were allowed to drink water during breaks in the class. Heart rate was monitored
continuously.
Determination of EPOC
At the conclusion of the class a blood lactate sample was taken and the subject was reconnected to the
gas analysis equipment for an initial period of 15 minutes and then 5 minutes every 15 minutes thereafter,
until 60 minutes had passed since the conclusion of the class. Further blood lactate samples were taken at
15, 30 and 60 minutes post-class. Oxygen consumption in excess of RMR was calculated and plotted as a
function of time. Total EPOC was taken as the area under the curve.
© 2007 Les Mills International Limited 67
Figure 1: Measurement of Resting Metabolic Rate (RMR)
Table 5: Schedule of EPOC session
Duration Activity
6:30am-7:00am Seated Rest
7:00am-7:15am Determination of RMR
7:15am-8:15am BODYPUMP™ class
8:15am-8:30am EPOC collection 1
8:30am-8:40am Seated Rest
8:40am-8:45am EPOC collection 2
8:45am-8:55am Seated Rest
8:55am-9:00am EPOC collection 3
9:00am-9:10am Seated Rest
9:10am-9:15am EPOC collection 4
RESULTS
This study sought to quantify the excess post-exercise oxygen consumption (EPOC) that occurs as a result
of performing a BODYPUMP™ class. Twelve male subjects performed two sessions; the first consisting of
body composition assessment and a VO2 max test and the second an EPOC session which consisted of a
BODYPUMP™ class and pre-and post-measurement of metabolic rate. Results are presented in Tables 6-
12.
© 2007 Les Mills International Limited 68
Table 6: Body composition and VO2 max of subjects
Variable Mean (SD)
ISAK Sum of 8 Skinfolds (mm) 79.3 (25.7)
Percent Body Fat 13.2 (3.2)
Lean Body Mass (kg) 70.0 (4.1)
VO2 max (L/min) 4.37 (0.60)
VO2 max (ml/kg/min) 54.7 (7.2)
Maximum Heart Rate 183.3
The subjects were generally of moderate-high aerobic fitness and had on average, 70 kg of lean body
mass. During the BODYPUMP™ class the average (SD) heart rate was 118 (19) which was 64 (9)% of
each individual’s maximum heart rate. Subjects spent an average of 20 minutes above 70% of maximum
heart rate.
Table 7: Subjects heart rate during BODYPUMP™ class
Variable Mean (SD)
Average Heart Rate During Class 118 (19.0)
Average Heart Rate during class as a % of Maximum Heart Rate 64 (9.0)
Maximum Heart Rate During Class 150 (21.0)
Maximum Heart Rate during class as a % of Maximum Heart Rate 82 (11.0)
Minutes Above 50% Maximum Heart Rate 53 (3.0)
Minutes Above 60% Maximum Heart Rate 35 (17.0)
Minutes Above 70% Maximum Heart Rate 20 (16.0)
Minutes Above 80% Maximum Heart Rate 7 (7.0)
Minutes Above 90% Maximum Heart Rate 0.3 (0.7)
Table 8: Subject loads during BODYPUMP™ class
Track / Muscle Group Load (kg) Mean (SD)
Warmup 15.4 (1.4)
Legs (Squats) 37.9 (8.6)
Chest 28.3 (5.5)
Back 26.7 (6.9)
Triceps 15.8 (3.3)
Biceps 15.6 (2.6)
Legs (Split Squats/Lunges) 19.8 (8.6)
Shoulders 14.2 (3.4)
Total Class Load 173.8 (33.5)
© 2007 Les Mills International Limited 69
The loads used during the current study provide an indication of what male subjects with moderate to high
experience use during a BODYPUMP™ class. These numbers are in stark contrast to loads used by
Stanforth et al (2000) in their assessment of aerobic demand of BODYPUMP™.
Table 9: Blood Lactate Concentration following BODYPUMP™
Table 10: Resting Metabolic Rate and EPOC of subjects
Variable Mean (SD)
Resting Metabolic Rate (kcal/min) 1.26 (0.31)
Resting Metabolic Rate (LO2/min) 0.254 (0.064)
EPOC (kcal) 38.95 (10.2)
EPOC (LO2) 7.63 (2.1)
EPOC (kcal per 80 kg body mass) 39.62 (12.1)
EPOC (LO2 per 80 kg body mass) 7.8 (2.4)
EPOC (kcal per 70 kg of lean body mass) 39.05 (10.5)
EPOC (LO2 per 70 kg of lean body mass) 7.7 (2.1)
EPOC following BODYPUMP™ was 38.95 kcal with a range of 27.4 kcal to 61.7 kcal. An average of 7.63
liters of oxygen was consumed in addition to resting levels in the 60 minutes following the class.
Table 11: EPOC of experienced and inexperienced BODYPUMP™ subject
Group Mean (SD) EPOC
Experienced (n=5) 32.3 (4.9)
Inexperienced (n=7) 43.7 (10.6)
Experienced subjects produced an average EPOC of 32.3, while the inexperienced subjects produced an
average of 43.7 kcal.
Time of Sample Lactate Concentration (mmol/L)
Resting 1.83 (0.4)
During Cooldown Track 6.41 (2.0)
15 Minutes Post-Class 3.65 (1.3)
30 Minutes Post-Class 2.54 (0.5)
60 Minutes Post-Class 2.03 (0.5)
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Table 12: Relationship between load, intensity and EPOC
Load Average HR during class as a
% of Maximum HR VO2 max
EPOC -0.6916 0.123 -0.525
Load 0.388 0.712
Average HR during class as a % of Maximum HR
-0.4152
DISCUSSION
Excess post-exercise oxygen consumption may be an important consideration for many reasons, including
its possible effect on body mass and body composition. The EPOC values reported in previous research
investigating traditional resistance or aerobic exercise range from 9.3 to 95 kcal. The average EPOC found
in the current study was 38.95 kcal. When scaled to a body mass of 80 kg, this value was 39.62 kcal and
when scaled to 70 kg of lean body mass, this value was 39.0 kcal. These values are similar to values
reported by other authors.
The finding of previous research[14,23]
, differed with regard to calorie consumption during a BODYPUMP™
session. Pfitzinger et al (1999) reported 486 (81.9) kcal, while Stanforth et al. (2000) reported 308 (42) kcal
for an 80 kg male. The methodological differences between these two studies that explain the variation in
findings are in the selection of subjects (experienced vs novice) and the exercise intensity (high vs low).
Using the average of these studies we can estimate that a typical 80 kg male (neither experienced nor
inexperienced) performing a BODYPUMP™ class will consume approximately 397 kcal. In addition to this,
they will consume approximately 40 calories in the post-exercise period. As shown in Table 13 (below) this
represents a total caloric expenditure of 437.
Table 13: Total calorie consumption associated with a BODYPUMP™ session
BODYPUMP™ + EPOC = TOTAL ENERGY EXPENDITURE
397 + 40 = 437
The EPOC measured in this study equates to approximately 10% of the previously measured calorie
consumption during the class. This relationship is very general, however, as illustrated by the fact that
heavier subjects tended to consume more calories during a BODYPUMP™ class while some of the highest
individual EPOC levels in the current study were recorded by some of the lightest subjects.
Previous research has suggested that subject fitness level and experience with the particular exercise
session has a major role in the size of EPOC. Fitness level as represented by VO2 max was moderately
negatively correlated (r = -0.525), with EPOC lending some support to the notion that a higher VO2 max will
© 2007 Les Mills International Limited 71
result in a lower EPOC. Unfortunately, defining fitness level using VO2 max does not identify those subjects
who were experienced with BODYPUMP™. There were five subjects who were regular participants
(experienced) of BODYPUMP™ and there were seven subjects who were not regular participants
(inexperienced). The EPOC of the experienced subjects was 32.3 (4.9) kcal as compared to 43.7 (10.6)
kcal for the inexperienced subjects. This difference was statistically significant at the 0.05 level. The
relationship between load and EPOC was unexpected. There was a correlation of –0.69 between total load
used by the subjects (the sum of the load used for all the tracks) and EPOC. This suggests that the lower
the load, the higher the EPOC. Upon consideration of the individual data it was clear that this represented
the difference between experienced and inexperienced subjects. Experienced subjects used greater loads
but produced lesser amounts of EPOC compared to the inexperienced subjects. This suggests that the
stimulus that BODYPUMP™ was providing was having a lesser effect on the experienced subjects despite
the increased loads. There was a moderate-strong correlation (r=0.712) between aerobic fitness and load
used during BODYPUMP™. This suggests that a moderate to high level of aerobic fitness improves the
ability to work hard and use high loads during BODYPUMP™.
Measuring EPOC in such a controlled manner is necessary to determine the exact amount of calories
consumed in excess of resting metabolic rate. However, in reality, a person finishes a class and continues
to be active as they shower, eat and perform daily activities. This may prolong and enhance the EPOC
associated with exercise. EPOC in excess of 24 hours has been reported; however, daily activities were
performed and three meals were eaten in this time. More research needs to be performed on how meals
and daily activities prolong EPOC.
The EPOC response has two components; a fast component and a slow component. The fast component
of EPOC is the first few minutes after exercise finishes where metabolic rate is considerably elevated. This
large elevation rapidly decreases and is followed by a slow component where metabolic rate is only slightly
elevated and gradually returns to resting levels. Blood lactate concentrations provide some insight to the
recovery of the body following exercise. Table 9 shows that lactate average levels were 6.41 at the
immediate conclusion of the class but had decreased to 3.65 within 15 minutes and 2.54 within 30 minutes.
As the subjects were required to sit quietly following the class the lactate removal processes were not given
much assistance. Had normal post-class activities been performed this removal would have been much
more rapid. If metabolic rate had been measured from the end of the final workout track (the start of the
cooldown track) then EPOC would likely have been much higher as there would have been an extra five
minutes of data during the fast component of EPOC.
SUMMARY
The EPOC following BODYPUMP™ is similar to that measured following other activities such as treadmill
running, cycling, resistance training and circuit training. This EPOC was equivalent to approximately 10% of
the previously measured exercise sessions’ calories. EPOC was affected by level of experience with the
© 2007 Les Mills International Limited 72
class but no significant relationships were found between load, VO2 max or exercising heart rate and
EPOC. The main points of the study are:
a) The average (SD) EPOC following BODYPUMP™ was 38.95 (10.2) kcal.
b) Subjects who were inexperienced with BODYPUMP™ and not regular class participants had
higher EPOC levels than those who were experienced and regular participants
c) Average heart rates during BODYPUMP™ were 64% of maximum heart rate
The notion that regular performance of BODYPUMP™ reduces body fat has experimental and anecdotal
support. The role that EPOC plays in this reduction in body fat was previously unclear. EPOC contributes
approximately 40 kcal to daily energy expenditure if a BODYPUMP™ session is performed. These
additional calories may contribute to an accelerated improvement in body composition.
To date, BODYPUMP™ is a relatively unresearched type of exercise. Areas of future research should
include the further documentation of exercise intensities (as indicated by heart rate) in a large and diverse
population and a replication of the study investigating the longitudinal effects of BODYPUMP™ on body
composition.
© 2007 Les Mills International Limited 73
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