the physiological effects of competition …jass.neuro.wisc.edu/2011/01/the physiological effects...
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Borchert, Brown, Ritchie, Vaughn 1
THE PHYSIOLOGICAL EFFECTS OF COMPETITION ON EXERCISE
PERFORMANCE
Megan Borchert, Samantha Brown, Mark Ritchie, Deidre Vaughn
Physiology 435, Lab 602, Group 12
April 7, 2011
Abstract
Previous research on exercise performance has focused on the psychological effects. Our
goal was to quantify the effects of competition on exercise through physiological responses
measured in a group of healthy college students. To induce a physiological, competitive
reaction, participants in the experimental group cycled alongside another student after an
initial solo trial. In the control group, participants rode two solo trials to provide a baseline
against which the experimental group could be compared. Mean arterial pressure, tidal
volume, and heart rate were measured both before and after the trials to determine exertion
level. The results of this study show that there is a strong correlation between riding
alongside someone else and an increased exertion level. In these cases, an increase in
average heart rate, mean arterial pressure, and tidal volume were observed. Specifically,
females showed an increase in average heart rate of 24.2 beats per minute (p-value 0.203)
and a decrease in time of 34 seconds (p-value 0.082). Based on this assessment, further
investigation regarding female and male interactions in competition could be an especially
interesting area of research. Utilizing such research could lead to more effective and
intense exercise sessions, higher athletic performance, and as a result, healthier lifestyles.
Introduction
Competition is considered to be a strong motivator for increased performance in
many settings, whether it is academics, athletics, or job performance (Cooke 2011). Given
this, the goal of this experiment is to further investigate the implications of competition
during athletic training, specifically when no explicit competition is defined. The
performance of an individual varies due to both personal motivation and the desire to out-
Borchert, Brown, Ritchie, Vaughn 2
perform another individual. While previous studies have used tangible rewards, this study
focuses on the internal motivation determined by the characteristics of an individual’s
personality (Cooke 2011, Viru 2010).
We have chosen to focus on gathering physiological data to assess the competitive
response of an individual, while still acknowledging the effects of one’s personality. To
monitor this, heart rate, mean arterial blood pressure, and respiration will be measured both
before and after each trial. The predicted result is that an increase in all three of these
variables will occur to a greater extent due to the presence of a competitor as compared to
the subject’s solo trial.
Researching this particular subject area could provide insight into the most effective
exercise strategies in both non-athletic and athletic situations. In non-athletic situations,
this may have implications as simple as going to the gym with a friend to increase the
effectiveness of a work out. In an athletic setting, cardiovascular training could be
modified to include more group or paired exercise to simulate the effect of spectators and
competitors in an actual competition.
Materials and Methods
Twelve participants were selected from a pool of willing college students ranging
from 19-24 years of age, including six women and six men. One male and one female
served as negative controls and the remaining ten composed our experimental group. At
the beginning of each trial, participants were read a standard script explaining that they
would be completing two runs of one mile each on a stationary bike (See Appendix B). It
Borchert, Brown, Ritchie, Vaughn 3
was explained that the participant would be given time to rest between the trials and that
several physiological measurements would be taken at given points in the trial. They also
signed a consent form stating they had no preexisting medical conditions and that they
would not share the experimental design with other potential participants (see Appendix A).
Physiological measurements were taken before the first trial, after the first trial, and
after the second trial (See Appendix C). Baseline and experimental respiration was
measured using the spirometer. Each participant was asked to breath into the spirometer
until a consistent reading was captured. The spirometer was allowed to run at 160 mm/min
while recording. From the spirometer reading, tidal volume of each participant was
observed and recorded. Baseline and experimental heart rate were observed with the
electrocardiogram (ECG) and measured manually from the carotid artery. Electrodes were
placed on the meaty part of the participants’ ventral forearms and lower calves, and a single
lead reading was recorded. Lastly, blood pressure was taken manually, by two team
members, using a double headed stethoscope and a blood pressure cuff (see Appendix C).
During their trial, participants were instructed to complete one mile on the
stationary bike with the instructions “Bike at your own pace, keeping mind you will have to
complete two one-mile trials. Ready? On your mark, get set, go.” The participants rode the
trial alongside a second unoccupied stationary bike. They were allowed to see the distance
they had biked and the RPM at which they were biking but not the time elapsed.
Upon completion of the first run, participants were instructed to move quickly off
the bike and into position so all the physiological measurements could be recorded. After
the data collection, participants were instructed to return after 15 minutes so that their heart
Borchert, Brown, Ritchie, Vaughn 4
rate could be measured manually to determine if they had returned to baseline. Baseline
was defined as a range of +/- 15 beats per minute of their resting heart rate, as measured
before the first trial.
Experimental participants were then instructed to ride the stationary bike for the
second trial with no instructions regarding pace stating simply, “Ready? On your mark, get
set, go.” Shortly before the participants began, they were joined by the male standardized
competitor that rode on the stationary bike alongside their own. This competitor was used
in every trial, and he maintained a high, consistent level of exertion during each
participant’s second trial. Each participant was accompanied by the standardized
competitor for the time it took the participant to complete 0.9 miles. When the
standardized competitor appeared, some participants caught on to the competitive aspect of
the experiment. One male participant’s data was excluded from the results due to his open
admission of purposely trying to defy his perceived expectations of the study. Due to the
low number of participants in this study, this greatly skewed the male experimental group’s
data.
Control group participants still completed the second trial but without the
standardized competitor riding alongside them. The data from these trials were included as
a negative control. Upon completion of the second run, the participant was again instructed
to move quickly off the bike and into position so all the physiological measurements could
be recorded. At the completion of the trial, participants were allowed to ask any questions
they had about the experimental design.
Borchert, Brown, Ritchie, Vaughn 5
Results
To assess the participants’ level of exertion, physiological measurements of heart rate,
mean arterial blood pressure and tidal volume were recorded (See Appendix D). The
average change in physiological measurements, calculated by the difference in average
measurements between post trial two and post trial one, are presented in Table 1. Data is
organized in groups based on gender and experimental group. Each of the three
physiological measures shows an increase in the average value with the second
(competitive) trial compared to the first trial for the experimental group, whereas the
controls show less variation between the two trials. Table 1 illustrates that none of the
physiological measures show statistical significance, with a p-value ≤ 0.05, but that the
females’ p-value is lower, and thus more significant, than the males’ in each physiological
measure.
Table 1
*Experimental Males excludes single experimental outlier.
Average Change in Physiological Measures (Post 2-Post 1)
MAP (mm Hg)
p-value HR
(beats/min)
p-value Tidal Volume
(mL)
p-value
Experimental Females 1.8 0.624412204 24.2 0.203312599 300 0.39453812
Control Female 1 21 -299
Experimental Males* 3.75 0.756076377 1.5 0.916655386 252.75 0.66788116
Control Male -2 -2 -1
Borchert, Brown, Ritchie, Vaughn 6
Figures 1, 2 and 3 show the average change in each of the three physiological measures,
calculated by the difference of post trial two minus post trial one. An average increase is
seen for each of the three physiological measures in the experimental group, whereas the
controls do not show the same trend for each measurement, some even showing a slight
decrease in measurements from post trial one to post trial two. Females show a greater
average increase in heart rate between trial one and trial two compared to males (24.2 beats
per minute and 1.5 beats per minute, respectively), whereas males show a greater average
increase in mean arterial pressure between the two trials (3.75 mm Hg and 1.8 mm Hg,
respectively). Females also show a greater average increase in average tidal volume
compared to males (300 mL and 252.75 mL, respectively), although this difference is not as
pronounced.
Figure 1
Average change in heart rate between trial one and trial two for experimental and control groups. Difference
calculated as the average heart rate of trial two minus the average heart rate of trial one.
*Experimental Males excludes single experimental outlier.
-5
0
5
10
15
20
25
30
Experimental
Females
Control Female Experimental
Males*
Control Male
bea
ts/m
inu
te
Average Change in Heart Rate
Borchert, Brown, Ritchie, Vaughn 7
Figure 2
Average change in mean arterial pressure between trial one and trial two for experimental and control groups.
Difference calculated as the average mean arterial pressure of trial two minus the average mean arterial
pressure of trial one.
*Experimental Males excludes single experimental outlier.
Figure 3
Average change in tidal volume between trial one and trial two for experimental and control groups.
Difference calculated as the average tidal volume of trial two minus the average tidal volume of trial one.
*Experimental Males excludes single experimental outlier.
-3
-2
-1
0
1
2
3
4
5
Experimental
Females
Control Female Experimental
Males*
Control Male
mm
Hg
Average Change in Mean Arterial
Pressure
-400
-300
-200
-100
0
100
200
300
400
Experimental
Females
Control Female Experimental
Males*
Control Male
mL
Average Change in Tidal Volume
Borchert, Brown, Ritchie, Vaughn 8
Difference in time to complete each trial for both males and females decreased in experimental
subjects. Females show an average decrease in time to complete trial two of 34 seconds with a p-
value of 0.0819, whereas males show an average decrease of four seconds with a p-value of 0.6647.
In comparison, the female control has no change in time to completion between trial one and trial
two and the male control decreases by 13 seconds with trial two. This demonstrates an increase in
exertion with competition in the second trial.
Figure 2
Difference in time to complete trial one versus trial two for each female participant, calculated as trial one
time minus trial two time. Average increase of 34 seconds for females and p-value of 0.0819 calculated for
change in time to complete trial. The control female saw no change in time between the two trials.
0
10
20
30
40
50
60
1 2 3 4 5
Ch
an
ge
in T
ime
(sec
on
ds)
Participant
Female Time: Trial 1-Trial 2
Female
control
change in
time
Borchert, Brown, Ritchie, Vaughn 9
Figure 5
Difference in time to complete trial one versus trial two for each male participant*, calculated as trial one time
minus trial two time. Average increase of four seconds and p-value of 0.6647 calculated for change in time to
complete trial.
*Experimental Males excludes single experimental outlier.
Discussion
The average increase in physiological measures seen with the experimental group
between trial one and trial two inferred an increased level of exertion in a competitive
setting. This increased exertion was evident in both sexes. This finding is consistent with
previous research regarding increases in heart rate, blood pressure, and other physiological
measures in competitive versus non-competitive settings (Cooke 2011, Harrison 2001).
Results from this study showed that females had a much greater average increase in
heart rate as compared to males (24.2 beats per minute compared to 1.5 beats per minute,
respectively). While previous research has illuminated very little in competitive trends
between females and males in settings comparable to this study, many studies have
investigated personality and used other psychological assessments of the individual as it
-7
-2
3
8
13
18
1 2 3 4Ch
an
ge
in T
ime
(sec
on
ds)
Participant
Male Time: Trial 1-Trial 2
Male
control
change in
time
Borchert, Brown, Ritchie, Vaughn 10
relates to competitiveness (Gill 1988). In contrast, this experiment focused solely on
physiological measures in assessing exertion with competition. Previous research has also
used asocial settings to analyze competitiveness, whereas this experiment included a live
standardized competitor, complicating the results with emotional interaction,
communication, and variability between sexes.
The differences seen between sexes for each physiological measure may be
indicative of other factors affecting competition, specifically emotions such as anxiety,
attraction, or joy (Cooke 2011). Female participants may have reacted differently to the
male standardized competitor than males. They may have been more conscientious, had a
desire to impress, or have been attracted to the male competitor, thus increasing heart rate
in the competitive setting (Cooke 2011). A future experiment that deserves attention would
be running more trials with a standardized competitor of the opposite sex. These
intrasexual and intersexual competitions may invoke different responses than running all
participants against a male competitor. These experiments could use four experimental
groups: male standardized competitor with male and female participants and a female
standardized competitor with both male and female participants. The control groups would
remain the same with participants riding two solo trials. Unfortunately, the comparisons
found in this study were based on a small pool of experimental participants and only two
controls, limiting the ability to generalize results. A larger experimental and control group
may have provided greater significance and applicability of the results.
A measurement that was taken, although not fully utilized in analyzing the results of
this study, was the time elapsed to complete each trial. While this measurement is not
purely physiological, it implies an increased performance level in the participants, with trial
Borchert, Brown, Ritchie, Vaughn 11
run times decreasing as much as 50 seconds with an average of a 34 second decrease in
females and a 4 second decrease in males. In conjunction with the other physiological
variables, this measurement further supports the hypothesis that competition enhances
performance level.
An additional complication of this study was that a three-minute mile appeared to be
at the upper limits of exertion. People who rode at under three minutes the first time had a
hard time going any faster than that during the second trial. This effect could be reduced by
extending the length of the trials to deter participants from operating with a sprint
mentality. A further benefit of this increase in distance would be ensuring a more complete
transition from a resting state to a performance level.
With this change, fatigue will be an increased issue. To remedy this, the
participants could be given longer breaks between trials or asked to perform an analogous
trial on a separate day. If the second trial were performed on a different day, taking all of
the participant’s vitals again – instead of just the heart rate – would be necessary to account
for any day-to-day variation.
An ideal, albeit implausible, alteration to the experimental procedure that would
improve the solo trial would be to remove all the spectators, including group data takers,
from the room. This would provide a situation where the person’s motivation in exercising
is entirely internal. As the experiment was set up, there were at least four spectators in the
room at any given time during the first, solo trial. This change would require machinery
that was unavailable. Also, covering up the display completely could help to discourage
the participant’s urge to out-compete their initial trial, providing a more natural pace.
Borchert, Brown, Ritchie, Vaughn 12
During the second trial, when the standardized competitor appeared, many
participants developed an inkling of the experimental design. Some participants conformed
to what they perceived as expected results while others consciously and openly admitted to
tampering with their trial time. One male participant’s data was excluded from the results
due to his open admission of purposely trying to defy his perceived expectations of the
study. Due to the low number of participants in this study, this greatly skewed the male
experimental group’s data. This type of influence could be reduced by having random
participants with no former relationships to any group members. To account for this, with
limited availability of participants, it was made sure that experimental participants had no
former relationship with the standardized competitor.
For future experimental designs, swapping the two trials so that the competitive run
is first could help to reduce the bias created by people figuring out the goal of the research.
This way, the participant may be less likely to understand the objective until the second
trial and the results will not be affected as greatly. Also, instead of direct competition, a
virtual competitor could be used to remove the bias of gender, physical ability, and verbal
interaction. By applying these approaches, the underlying question of the experiment may
be veiled to a greater extent.
Borchert, Brown, Ritchie, Vaughn 13
Works Cited
Cooke, Andrew, Maria Kavussanu, David McIntyre, and Christopher Ring. "Effects of
Competition on Endurance Performance and the Underlying Psychological and
Physiological Mechanisms." Biological Psychology 86 (2011): 370-78. Web. 22 Mar. 2011.
Gill, Diane L., and David A. Dzewaltowski. "Competitive Orientations Among Intercollegiate
Athletes: Is Winning the Only Thing?" The Sport Psychologist 2 (1988): 212-21. Web. 22
Mar. 2011.
Harrison, Lesley K., Samantha Denning, Helen L. Easton, Jennifer C. Hall, Victoria E. Burns,
Christopher Ring, and Douglas Carroll. "The Effects of Competition and Competitiveness
on Cardiovascular Activity." Psychophysiology 38 (2001): 601-06. Web. 22 Mar. 2011.
Viru, M., A. C. Hackney, K. Karelson, T. Janson, M. Kuus, and A. Viru. "Competition Effects on
Physiological Responses to Exercise: Performance, Cardiorespiratory, and Hormonal
Factors." Acta Physiologica Hungarica 97 (2010): 22-30. Web. 22 Mar. 2011.
Borchert, Brown, Ritchie, Vaughn 14
Appendix
A) Consent Form
Liability Waiver/Consent Form
I agree to voluntarily take part in this experimental study performed by Group 12 of Lab Section
602 of Physiology 435. I understand that the activity required by this experiment will stress the
cardio-respiratory system and I affirm that I am of reasonable physical condition and will be able
to withstand the testing.
It is not the responsibility of Group 12 or the Physiology department if something should happen
during or after the process including, but not limited to, accidental injury or death. Any pre-
existing conditions that could affect my ability to take part in this exercise should be disclosed
prior to the experiment. I understand that I am able to decline my participation in this activity at
any time due to any circumstance.
Confidentiality Agreement
I agree to not disclose any of the information that I was told in the process of the experiment,
including, but not limited to, procedure and experimental purpose.
In return, Group 12 agrees any information disclosure will be totally anonymous, and your
personal results will not be shared with others.
I have read both of these waivers and agree to the terms set forth.
Signature:________________________________________________________
Date:_______________
Print Name:______________________________________________________
Borchert, Brown, Ritchie, Vaughn 15
B) Script
First trial: Thank you for coming in and participating in our experiment today. We will be
starting by measuring your blood pressure with the arm cuff and rate of breathing and tidal
volume using the spirometer, as well as performing an ECG. You will then be riding the
stationary bike for one mile. After you have completed one mile, we will be retaking the
measurements at which point you will be given half an hour to rest before returning to
repeat the experiment.
After measurements have been taken – Remember, this is your first of two one-mile trials.
Please, go at your own pace keeping in mind that you will be repeating another trial in 15
minutes.
On your mark, get set, go.
Second trial: Before your ride this time we will just be taking your blood pressure. After
your last one-mile ride, we will need you to come back and sit on the chair as we will be
measuring ALL stats again: blood pressure, breathing, and ECG.
Borchert, Brown, Ritchie, Vaughn 16
C) Data Collection
a)
b)
c)
Figure 6
Images of electrocardiogram (ECG) read out for participant 1 for pre-trial 1 (a), post-trial 1 (b) and post-trial 2
(c). ECG was used to calculate heart rate.
(a) (b) (c)
Figure 7
Images of spirometer read out for participant 8 for post-trial 2 (a), post-trial 1 (b) and pre-trial 1 (c). The
spirometer was used to tidal volume.
Borchert, Brown, Ritchie, Vaughn 17
Figure 8
Photo of experimental set up illustrating ECG station (a), blood pressure station (b) with cuff (*), and
spirometer (c).
Figure 9
Photo of experimental set up for trial 2, illustrating an experimental female with standardized male
competitor.
(b)
(a)
(c)
*
Borchert, Brown, Ritchie, Vaughn 18
D) Data
BLOOD PRESSURE
(Bold text is the average)
MAP HEART RATE (MANUAL) HEART RATE (ECG) TIDAL VOLUME TIME
PARTICIPANT SEX AGE Pre 1 Post 1 Post 2 Pre 1 Post 1 Post 2 Pre 1 Post 1 Pre 2 Post 2 Pre 1 Post 1 Post 2 Pre
1
Post
1
Post
2
1 2
(1) Katie F 21 130/68
120/72
125/70
135/75
140/78
137/77
150/70
162/70
156/70
88 97 99 84 132 88 160 115 143 167 481 978 1328 4:36 3:46
(2) Nick (control) M 22 160/60
162/82
161/71
200/75
220/70
210/73
210/65
218/70
214/68
101 119 117 84 104 76 116 80 107 105 1370 2024 2023 3:10 2:57
(3) Krisa (control) F 19 120/65
117/68
119/67
130/62
138/66
134/64
145/65
125/66
135/66
84 88 89 64 112 68 116 74 76 97 1488 2150 1851 3:31 3:31
(4) Andy * M 22 135/70
138/82
137/76
165/72
170/68
168/70
145/70
142/75
144/73
96 103 97 64 84 68 76 64 74 62 1138 2878 1345 4:00 4:18
(5) Adam M 21 110/55
102/58
106/57
135/55
142/62
139/59
140/55
138/62
139/59
73 86 86 64 144 80 160 76 158 162 3148 2918 2965 3:01 2:56
(6) Han M 24 100/65
102/76
101/71
110/60
117/72
114/66
105/60
122/79
135/70
81 82 92 64 112 72 124 64 111 115 828 1599 1706 3:31 3:23
(7) Katie F 21 120/65
115/62
118/64
150/55
142/63
146/59
170/55
165/62
168/59
82 88 95 84 132 88 156 92 125 167 3055 2267 2135 3:32 2:54
(8) Tiffany F 23 118/58
114/62
116/60
150/62
152/62
151/62
170/60
178/58
174/59
79 92 97 60 116 72 160 57 107 162 740 1461 2174 3:39 2:57
(9) Maria F 22 95/60
98/62
97/61
117/68
118/70
118/69
130/60
130/62
130/61
73 85 84 72 96 76 116 80 103 91 600 1000 1115 4:14 3:48
(10) Alex M 21 165/85
160/90
163/88
205/65
209/70
207/68
200/70
190/72
195/71
113 114 112 80 140 100 156 107 140 140 1380 1903 1942 3:14 3:06
(11) Willie M 22 165/75
162/80
164/78
195/70
190/72
193/71
205/75
208/75
207/75
107 112 119 72 128 80 140 80 143 141 1520 2830 3648 2:56 2:59
(12) Alyssa F 21 110/65
112/70
111/68
155/65
156/70
156/68
162/50
162/67
162/59
82 97 93 64 168 72 192 81 150 162 871 956 1410 3:36 3:22
Borchert, Brown, Ritchie, Vaughn 19