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International Journal o f Sport Nutrition, 1996, 6, 24-40 0 1996 Human Kinetics Publishers. Inc.

Treatment of Athletic Amenorrhea With a Diet and Training Intervention Program

Christine A. Dueck, Kathleen S. Matt, Melinda M. Manore, and James S. Skinner

The purpose of this study was to determine the effect of a 15-week diet and exercise intervention program on energy balance, hormonal profiles, body composition, and menstrual function of an amenorrheic endurance athlete. The intervention program reduced training 1 daylweek and included the use of a sport nutrition beverage providing 360 kcallday. Three eumenorrheic athletes served as a comparison group and were monitored over the same 15-week period. The amenorrheic athlete experienced a transition from negative to positive energy balance, increased body fat from 8.2 to 14.4%, increased fasting luteinizing hormone (LH) from 3.9 to 7.3 mIU/ml, and decreased fasting cortisol from 41.2 to 33.2 ~g ld l . The eumenorrheic subjects showed a 0.4% reduction in body fat, a decrease in follicular phase levels of LH from 7.9 to 6.5 mIU/ml, and no change in cortisol. These results suggest that nonpharmacological treatment can contribute to reestablishing normal hormonal profiles and menstrual cyclicity in amenorrheic athletes.

Key Words: energy balance, menstrual dysfunction, reproductive inhibition, female athlete

The passage of Title IX in the 1970s made it possible for female athletes to join their male counterparts in collegiate athletics. It also brought with it the demanding training and performance expectations associated with competitive sports. Although most female athletes meet these training demands without harm or incidence, some investigators report that female endurance athletes experience negative consequences, such as irregular menses or the complete cessation of menstrual function (6). As the amount of research data on competitive female athletes increases, it is apparent that strenuous exercise can have a significant negative impact on the endocrine, reproductive, and musculoskeletal systems (13, 15, 17).

The specific circumstances that initiate the onset and reversal of athletic menstrual dysfunction remain unclear. The underlying mechanisms are not

C.A. Dueck, K.S. Matt, and J.S. Skinner are with the Department of Exercise Science & Physical Education, Arizona State University, Tempe, AZ 85287-0404. M.M. Manore is with the Department of Human Development & Family Resources, Arizona State University.

Athletic Amenorrhea / 25

known, and it has not been determined whether amenorrhea is a single entity or a combination of several metabolic and hormonal abnormalities producing a common syndrome. It is clear, however, that the intensively training female athlete is at a much greater risk for developing menstrual dysfunction than her sedentary counterpart (3). The evidence for damaging side effects is substantial, and it has been well documented that amenorrheic athletes have a greater incidence of musculoskeletal distress and neuroendocrine aberrations (7, 15).

The high volume of intense physical training associated with competition may inhibit the neuroendocrine system, particularly the hypothalamic-pituitary- ovarian axis (15). Amenorrheic athletes typically display reduced levels of estradiol and progesterone and have hormonal profiles more similar to those of postmenopausal women than to those of their age-matched counterparts (13, 14). The reduced levels of endogenous estrogen associated with amenorrhea may prevent the formation of adequate bone density and the development of an appropriate "bone bank" (6, 13). In order to treat the hypoestrogenemia associated with amenorrhea and reduce the risk of developing poor bone density, many physicians prescribe hormonal therapy or place amenorrheic athletes on oral contraceptives (10). Unfortunately, many female athletes associate oral contraceptive use with performance-hindering side effects such as nausea, fatigue, and weight gain. Thus, these fears cause many female athletes to avoid seeking appropriate medical attention for their menstrual dysfunction. Prolonged periods of low estrogen increase the risk for stress fractures and the development of osteoporosis later in life.

The use of nonpharmacological modes for treating athletic amenorrhea has not been extensively investigated. Changes in lifestyle factors, such as dietary and training habits, may be an altemative treatment for amenorrheic athletes who are unwilling to adhere to hormonal therapy. This altemative treatment may be particularly beneficial in those athletes who do not have major body weight concerns or a distorted body image. The effectiveness of a dietary intervention, however, may be limited in athletes who have a history of disordered eating and express negative or unhealthy attitudes regarding food.

It is not unusual for female athletes to participate in two exercise training sessions per day, easily expending over 1,000 kcal per day in exercise alone. If energy intake does not meet these increased needs, a significant negative energy deficit will result. Thus, it has been suggested that the cessation of menstruation is an adaptation by the body to large metabolic demands that are not met by inadequate energy intakes, especially when energy demands are high (24).

The purpose of this study was to examine the effects of positive energy balance, produced by modifying both diet and exercise, on body composition, hormonal profile, and menstrual function of an amenorrheic athlete.

Methods

Subjects

A 19-year-old amenorrheic runner was placed on a diet and training intervention program for 15 weeks during the competitive portion of her sophomore collegiate track season. Menstrual function was lost during her freshman year when she switched from sprinting to distance events and consequently lost 9 kg over 3

26 / Dueck, Matt, Manore, and Skinner

months. She remained amenorrheic for 14 consecutive months prior to participat- ing in this study. Before the intervention program, her training regimen consisted of double workouts 7 days/week. Her running schedule included daily morning runs as well as afternoon runs on 4 days/week. She also lifted weights 3 days/ week. Her body weight at the start of the competitive season was 48 kg. She reported difficulty maintaining body weight during the previous track season and stated she had lost 3 kg by the end of the season. During the 6 months prior to this study, the subject complained of chronic fatigue, poor performance, and a high frequency of illness and injury.

Three ovulatory, eumenorrheic distance runners from the same track team served as a comparison group and were monitored over the same 15-week period. Subject characteristics are reported in Table 1. No subject reported a history of disordered eating, anorexia nervosa, bulimia nervosa, hormonal therapy, or oral contraceptive use. Experimental procedures were approved by the University Human Subjects Internal Review Board. All subjects were fully informed of the study's purpose, its possible risks, and the benefits of their participation prior to giving their informed consent.

Experimental Design

Data were collected on 1 amenorrheic athlete and 3 ovulatory eumenorrheic athletes over a 15-week period during the intercollegiate track season. Only the amenorrheic athlete was placed on the diet and training intervention program. One month prior to the start of the season and before the amenorrheic athlete was placed on the intervention program, a series of tests were conducted to establish baseline data for all subjects; tests included body composition, body fat distribution, bone mineral density (BMD), and fasting hormonal profiles.

Table 1 Characteristics of 1 Amenorrheic and 3 Eumenorrheic Athletes Before and After a 15-Week Track Season

Parameter

Amenorrheic athlete Eumenorrheic athletesb

Baseline Week 15 Baseline Week 15

Age (years) 19 Height (cm) 159 Weight (kg) 48.2 BMI (kg/m2) 19.1 Body fat (%)" 8.2 Fat-free mass (kg)" 41.7 Fat mass (kg)" 3.9 Age at menarche (years) 12.0 V02max (ml/kg/min) 54.0

"Based on dual-energy X-ray absorptiometry. bValues represent means + standard deviations.


These same parameters were measured at the end of the 15-week period. Due to the pulsatile nature of hormone release, a 4-hr serial blood draw was also performed on the amenorrheic athlete and 1 eumenorrheic subject at baseline and Week 15.

The dietary component of the intervention consisted of supplementing the daily diet of the amenorrheic athlete with one 11-oz serving of GatorProB sport nutrition beverage, a liquid formula containing 360 kcal/serving (59 g of carbohydrate, 17 g of protein, and 7 g of fat). The training component of the intervention consisted of adding 1 complete rest day to her weekly training regimen, thus reducing her training load from 7 days/week to 6 days/week. Weighed 7-day diet records and activity logs were completed by the amenorrheic athlete at baseline and at Week 4 of the intervention program. The baseline diet and activity records were collected to determine this athlete's typical diet and training behavior, while the second assessment (Week 4) was conducted to monitor compliance with the study protocol (i.e., we did not want the athlete to compensate for the intervention program by eating less or increasing her exercise). Thus, our goal was to adjust both diet and training to ensure that the athlete was in positive energy balance.

Body Composition and Bone Density

At baseline and after the 15-week period, percent body fat and body fat distribution were determined by hydrodensitometry and dual-energy X-ray absorptiometry (DEXA) (Lunar DPX, Madison, WI; software version 3.4). When using hydrodensitometry, we measured residual lung volume using the oxygen-dilution method (25). Percent body fat was derived using the Lohman equation adjusted for age and gender (12). When using DEXA, we determined values for total and regional percent body fat from the total body scan.

To determine regional body fat distribution, sections of the total body scan were defined by manual bisection. The region for determining percent arm fat was defined as the fingertips to the proximal end of the arm where it bisects the shoulder joint. The leg region was defined as the toes to the proximal end of the leg where the femoral neck bisects the pelvis line cut. The truncal region was defined as the area from the neck to just below the pelvis with distal cuts at the arm sockets and femoral necks. Bone density measurements were also performed on all subjects at baseline and Week 15 after the competitive season.

Bone density (measured in grams per square centimeter and percentage of age-matched norms) of the lumbar spine (L2-L4), the right proximal femur (femoral neck, trochanter, and Ward's triangle), and total body was determined by DEXA. Bone density data (Table 2) are provided solely as additional information regarding subject characteristics. Because the typical bone remodeling cycle exceeds the length of the 15-week intervention period, no interpretations should be inferred from this data. The coefficient of variation for the determination of soft tissue and bone density measurements by DEXA was calculated in our laboratory by repositioning subjects between scans and was determined to be 2%. More complete information regarding DEXA measurements has been published elsewhere (18).


Table 2 Bone Mineral Status of 1 Amenorrheic and 3 Eumenorrheic Athletes Before a 15-Week Track Season

Femoral neck Lumbar spine (L2-L4)

Density % age-matched Density % age-matched Subject (g/cm2) norms (g/cm2) norms

Amenorrheic athlete Baseline 1.088 115 1.266 11 1

Eumenorrheic athletesa Baseline 1.071 k 0.136 112 + 15 1.152 + 0,108 100 + 9

Note. Bone density data are provided solely as additional information regarding subject characteristics. Because the typical bone remodeling cycle exceeds the length of the 15- week intervention period, no interpretations should be inferred from these data. "slues represent means f. standard deviations.

Hormonal Assessment

Fasting venous blood samples were collected at baseline and Week 15 and analyzed for estradiol, progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and cortisol using radioimmunoassay kits (ICN Biomedical, Costa Mesa, CA). In the eumenon-heic subjects, a fasting blood sample was collected at three different times during the menstrual cycle: early follicular phase (Days 3-3, late follicular phase (Days 10-1 I), and midluteal phase (7-10 days postovulation). ~etermination of ovulation was based on detection of an increase in urinary LH with an OvukitB (Quidel, San Diego, CA).

To distinguish between differences in the pulsatile patterns of LH and cortisol, serial blood draws were conducted on the amenon-heic subject and 1 eumenon-heic subject at baseline and Week 15. An indwelling cannula was inserted into the forearm vein at 6:00 a.m. Serial blood sampling (5 ml/sample) was initiated at 6:30 a.m. and continued at 10-min intervals for 4 hr. All blood samples were drawn between 6:30 a.m. and 10:30 a.m. after an overnight fast and at least 12 hr after the last exercise session. The samples were placed on ice and immediately centrifuged, aliquoted, and then frozen in multiple aliquots at -70 "C until assayed. All samples were saved until the conclusion of the study and were assayed in batch. Samples were randomized both within and between assays to ensure that any differences either within or between subjects were not due to inter- and/or intraassay variation. Intraassay and interassay variances for all hormones measured were +6.2% and f 5.1 %, respectively.

Energy Balance

In the amenon-heic subject, consecutive 7-day weighed food records were used to determine energy and nutrient intake at baseline and Week 4 of the intervention program. Diet records were carefully reviewed with the subject at the time of


completion to verify accuracy. The amenorrheic subject was instructed to maintain her normal eating pattern and to not modify her daily caloric intake in order to compensate for the additional calories of the supplement. Diets were analyzed using Food Processor Plus (ESHA Research, Salem, OR) for energy and nutrient intakes.

A detailed 7-day training log and activity records were recorded concur- rently with the 7-day diet records at baseline and Week 4 of the 15-week period. This was done in order to estimate the amount of energy expended during each day of the amenorrheic subject's weekly training regimen. The amenorrheic subject was instructed to record specific daily activities every 15 min over seven consecutive 24-hr periods, as well as the intensity, heart rate, time to completion, pace, and total distance covered during each training session. The training log and activity records were reviewed with the athlete upon completion in order to check for completeness and accuracy.

The training and activity log data were analyzed using the exercise portion of Food Processor Plus (ESHA Research, Salem, OR; software version 5.0). This program calculates energy expenditure using the estimated basal metabolic rate, the caloric cost of each activity, and the thermic effect of food. Basal metabolic rate was calculated using the World Health Organization equation (8). Thermic effect of food was calculated at 6%. Energy balance was calculated as the difference between energy intake and energy expenditure.

To help verify subject compliance, the amenorrheic subject met with an investigator (C.A.D.) once each week, at which time her used cans of supplement were exchanged for the upcoming week's supply. The subject was also asked whether she had made any changes in her training regimen or daily energy intake that might have altered her energy status. In addition, the amenorrheic subject was contacted 3-4 times per week by telephone in order to "check in."

The investigator worked in collaboration with the track coach to ensure that the seasonal training schedule complied with the addition of 1 rest day to the amenorrheic athlete's training schedule. Thus, all modifications made to- the amenorrheic athlete's training regimen were done with permission of the coach and the athlete. Diet records and training logs were not collected from the eumenorrheic subjects.

Results

Body Composition

Hydrodensitometry and DEXA indicated that the amenorrheic athlete's body fat increased by approximately 6% during the 15-week intervention period from 8.2 to 14.4% (Table 3). Body weight increased by 2.7 kg in the amenorrheic subject from baseline (48.2 kg) to Week 15 (50.9 kg). In terms of body fat distribution, the largest regional gains were observed in the trunk, which showed a 7.1% increase from 4.0 to 11.1%, as compared to 4.6 and 1.5% increases in her arms and legs, respectively.

Conversely, the eumenorrheic athletes showed minimal losses in total body fat, ranging from -0.4 to - 1.6%, as determined by DEXA and hydrodensitometry. Mean total body weight also decreased slightly (-0.5 kg) in the eumenoqheic group. DEXA indicated that the largest regional losses occurred in the trunk


Table 3 Body Composition and Fat Distribution of 1 Amenorrheic and 3 Eumenorrheic Athletes Determined by DEXA and Hydrodensitometry Before and After a 15-Week Track Season

Subject % Total % Truncal % Arm % Leg body fat fat fat fat

Amenorrheic athlete Baseline 8.2 ( 8.6)" 4.0 7.0 16.0 Week 15 14.4 (14.0)" 11.1 8.5 20.6

Eumenorrheic athletesh Baseline 21.1 + 2.5 (20.1 f 2.3)a 22.2 f 2.2 17.2 f 4.4 28.7 + 4.5 Week 15 20.7 f 3.5 (18.5 + 2.7)" 17.9 + 0.8 14.3 + 3.2 27.5 f 4.4

'Based on hydrodensitometry. bValues represent means f standard deviations.

(-4.3%) followed by the arms and legs (-2.9 and -1.2%, respectively). However, these reported changes in body composition are very small and easily fall within the coefficient of variation for either method.

Hormonal Analysis

The intervention program appears to have had its greatest effect on the gonado- tropin hormone LH (Table 4). After the intervention program, the amenorrheic athlete showed an increase in serum levels of LH from 3.9 to 7.3 mIU/ml. Conversely, the eumenorrheic athletes displayed a reduction in early follicular- phase LH from the beginning to the end of the season (7.9 f 6.5 to 5.7 + 1.3 mIU/ml, respectively). A comparison of the pulsatile patterns of LH in the amenorrheic subject with 1 eumenorrheic subject further documents the large increase in LH that occurred after the intervention program (Figure 1, a and b). When expressed as the area under the curve, serum levels of LH increased by 148% in the amenorrheic athlete from baseline (1,280) to Week 15 (3,170). These results suggest that the intervention program was effective in increasing the amenorrheic subject's baseline LH to a level comparable with that of the eumenorrheic control subject during the early follicular phase of the menstrual cycle.

The amenorrheic subject also showed a reduction in serum cortisol over the intervention period, from 41.2 to 33.2 pg/dl (Table 4). At baseline, the amenorrheic subject had cortisol levels that on average were 55% greater than the mean eumenorrheic values during all phases of the menstrual cycle. The amenorrheic athlete's baseline cortisol values were 70% above the expected physiological range (7 to 24 pg/dl). By Week 15, cortisol for the amenorrheic subject was reduced but still averaged 21% greater than the eumenorrheic values and 37% above the expected physiological range. The eumenorrheic subjects showed no change in serum cortisol levels during the three phases of the menstrual cycle or during the 15-week track season.

Table 4 Fasting Hormonal Status of 1 Amenorrheic and 3 Eumenorrheic Athletes Before and After a 15-Week Track Season

LH FSH Estradiol Progesterone Cortisol Subject Timelphase (mIUIml) (mIU/mI) (~g/ml) (ng/ml) (~g ld l )

Amenorrheic athlete Baseline Week 15

Eumenorrheic athletesa Baseline A

B C

Week 15 A B C

2 3

Note. LH = luteinizing hormone; FSH = follicle-stimulating hormone; A = early follicular phase (Days 3-5); B = late follicular phase (Days 10- $, 11); C = midluteal phase (7-10 days postovulation). n

> "Values represent means f standard deviations. 2

Z?


LH (mlUlml) LH (mlUlml) Week 0

o Amen Week 15

~rr Amen - Eumen

Time (AM) Time (AM)

Figure 1 - Pulsatile pattern of luteinizing hormone (LH) over a 4-hr period at Week 0 and Week 15 in an amenorrheic athlete (AMEN) and a eumenorrheic control (EUMEN).

The pulsatile data (Figure 2, a and b) further document the reduction in serum cortisol levels in the amenorrheic subject. Cortisol values in both the amenorrheic and eumenorrheic subject decreased over time during the 4-hr serial draw. This pattern fits with the diurnal rhythm of cortisol, which reaches its peak in the early morning and then declines throughout midmorning until reaching its nadir in the late afternoon. At baseline, the pattern of decline in cortisol values was relatively slow in the amenorrheic subject. At Week 15, the pattern of decline was more rapid, resembling that of the eumenorrheic athlete during the first 2 hr of the 4-hr sampling period.

The gonadal steroid hormones estradiol and progesterone did not appear to be altered by the intervention program. Serum levels of estradiol decreased from 87.9 to 77.5 pg/nl in the amenorrheic athlete during the 15-week season and were dramatically lower than those of the eumenorrheic athletes during the luteal phase at baseline and Week 15 (144.9 + 41.2 and 125.1 + 36.7 pg/nl, respectively). A similar pattern was seen with progesterone, as these levels decreased in the amenorrheic athlete from Week 0 to Week 15, even though both values were within the normal range for the follicular phase of the menstrual cycle (0.2-0.9 ng/ml). The amenorrheic athlete's progesterone levels, however, were well below the expected luteal phase range (3.&35.0 ng/ml). In contrast, the eumenorrheic subjects had follicular phase progesterone values comparable to those in the normal range. The eumenorrheic subjects also displayed an eleva- tion in progesterone levels during the luteal phase, which is associated with a normal menstrual cycle.


Cortisol (ugldl) Week 0

,, Amen - Eumen

30 35 1 Cortisol (ugldl) Week 15

+ Amen

-0- Eurnen

7 8 9 10

Time (AM)

7 8 9 10 Time (AM)

Figure 2 -Pulsatile pattern of cortisol over a 4-hr period at Week 0 and Week 15 in an amenorrheic athlete (AMEN) and a eumenorrheic control (EUMEN).

Energy Balance

Prior to the intervention program, the amenorrheic athlete appeared to be in a state of negative energy balance (Table 5 ) and reported difficulty maintaining body weight. The 7-day training and activity logs and 7-day weighed diet records indicated that this athlete's self-reported energy intake was 3,045 kcallday, while estimated energy expenditure was 3,200 kcallday. The intervention program produced a positive energy balance. This was accomplished by adding one serving of GatorProB per day (360 kcallday), maintaining or slightly increasing her usual food intake, and reducing exercise energy expenditure by 12-16 mileslweek (approximately 1,400 kcallweek or 200 kcallday), accomplished in part by the incorporation of 1 complete rest day in the athlete's weekly training schedule.

Table 5 also gives the mean energy and nutrient intakes at baseline and at Week 4. In general, energy and macronutrient intake (grams per day) increased, but percentage of energy from these nutrients did not change. There was also a 21% increase in daily energy intake and 24%, 17%, and 15% increases in absolute intakes (grams per day) of carbohydrate, fat, and protein, respectively. At baseline, micronutrient intakes exceeded the Recommended Daily Allowance (RDA) (8) for all vitamins and minerals examined, except Vitamin D. At Week 4, all vitamin and mineral intakes increased due in part to the micronutrient supplementation of the GatorProB. The amenon-heic athlete was taking no other food or nutrient supplements.

Performance Outcomes and Posttraining Follow-Up It is important to note that the amenorrheic subject was highly motivated to participate in this project for personal health benefits. She had no history of disordered eating and no negative or unhealthy attitudes regarding food. During


Table 5 Estimated Mean Energy Balance and Nutrient Intakes of 1 Amenorrheic Athlete at Baseline and Week 4 of the Diet and Training Intervention Program

Nutrient Baseline Week 4"

Energy intake (kcallday) Energy expenditure (kcallday) Energy balance (intake - expenditure) Fat (glday)

% diet Carbohydrate (glday)

% diet Protein (glday)

% diet Cholesterol (mglday) Dietary fiber (glday) Vitamin A (IUJday) Thiamin (mglday) Riboflavin (mglday) Niacin (mglday) Vitamin B6 (mglday) Vitamin B 12 (pglday) Folate (yglday) Pantothenic acid (mglday) Vitamin C (mglday) Vitamin D (pglday) Calcium (mglday) Iron (mglday) Magnesium (mglday) Potassium (mglday) Zinc (mglday)

Note. All values represent 7-day means from weighed food records with percentage of RDA in parentheses. "Dietary data include one can of GatorProBJday, which contains 360 kcal, 59 g carbohydrate, 17 g protein, 7 g fat, and the following micronutrients as % of U.S. RDA: vitamin A, 25; vitamin C, 90; thiamin, 50; riboflavin, 50; niacin, 50; calcium, 30; iron, 30; vitamin D, 25; vitamin E, 35; vitamin B6, 50; folic acid, 50; vitamin B12, 50; phosphorus, 30; iodine, 30; magnesium, 30; zinc, 40; copper, 30; biotin, 50; pantothenic acid, 50.

the previous track season, she had difficulty maintaining a body weight of 48 kg and ended the season below 45 kg. She felt her low body weight had a negative effect on performance and contributed to her chronic fatigue and high frequency of injury. After using the dietary supplement (GatorProB) and reducing her training schedule from 7 to 6 dayslweek, she set more personal records than during any prior season, broke two school records, and qualified for the National Junior Collegiate Athletic Association National Track and Field Meet in several


events ranging from 800 m to 10,000 m. Thus, the body weight and fat gains were not viewed in a negative manner, especially considering the concurrent performance improvements.

Despite the transition toward a more normal hormonal profile, the amenorrheic subject did not resume menstruation within the 15-week intervention period. Although we would have liked to employ the intervention for 6-9 months, the subject was recruited to a university in the southeast. Consequently, it was possible to maintain a strong sense of control and close subject contact for only 15 weeks. However, we did correspond with her and encouraged her to supplement her daily diet with an additional 300-400 kcal. The subject reported that she did comply with our recommendation by adding either one serving of GatorProB (360 kcallday) or two Power Bars@ (460 kcallday) to her daily diet. Three months after her relocation, she resumed menstruation and has displayed normal menstrual function for two consecutive months.

Discussion

The 15-week diet and training intervention program brought the amenorrheic subject into positive energy balance, as evidenced by the gain in body weight. The increase in serum LH suggests that the intervention program removed inhibition on the reproductive axis and initiated some of the hormonal changes required for the resumption of menstrual cycles.

Energy Balance

It has been suggested that the cessation of reproductive function is an energy- conserving adaptation to an energy-deficient diet (l9,24). Numerous experiments have been designed to document the reduction in energy intake in amenorrheic athletes. These findings suggest that amenorrheic women consume diets similar in composition to those of eumenorrheic athletes but with smaller energy content (1 1, 17, 20). Five studies from the past 10 years report that the average daily energy intake for eumenorrheic runners is between 1,900 and 2,250 kcallday, whereas the average energy intake in amenorrheic runners is between 1,550 and 1,750 kcallday (6, 11, 17, 19, 20).

It should be noted, however, that these energy intakes were based on self- reports by athletes. Thus, some of the lower energy intakes may be due to underreporting. Research comparing 24-hr recall with the doubly labeled water method has indicated major differences in the results of these two techniques. The greatest discrepancies were found in those athletes most concerned about body weight (22). Regardless of these discrepancies, it remains plausible that anovulation and cessation of menstruation are adaptations by the body to metabolic demands that are not met by an inadequate energy intake. Evidence suggests that energy expenditure during high-performance training produces an energy drain resembling undernutrition (24). This energy drain may be especially detri- mental to lean individuals.

Prior to the intervention program, the amenorrheic subject's estimated energy intake was 3,045 kcallday with an estimated energy expenditure of 3,200 kcallday, which resulted in an energy deficit of approximately 155 kcallday. Through dietary supplementation and the addition of 1 day of complete rest to


her training regimen, the amenorrheic subject increased her energy intake to approximately 3,683 kcallday and reduced her mean daily energy expenditure to approximately 3,000 kcallday, resulting in an estimated positive energy balance of 683 kcallday. Consequently, she maintained a state of positive energy balance for the 15-week intervention period and gained 2.7 kg in body weight and 6% in total body fat. Typical of many well-trained athletes, the amenorrheic subject had a very structured daily routine that was seldom modified by extracurricular activities. Furthermore, she was extremely regimented with regard to her diet; thus, few changes in food type occurred during the 15-week intervention period.

The high energy cost associated with large volumes of intense aerobic training also contributes to the development of energy imbalance in athletes. Regardless of the sport, amenorrheic athletes consistently train more days per week and more months per year than their eumenorrheic counterparts. A survey by Lutter and Cushman (16) of 10-km and marathon race participants found that 62% of the amenorrheic runners trained 7 dayslweek compared to 9% of the eumenorrheic runners. Similar training habits were noted in the athletes who participated in the present study. Before the intervention program, the amenorrheic subject participated in 14 workouts and more than 20 hr of intense physical activity per week, while the eumenorrheic subjects trained 6 dayslweek and added a second workout only 3 dayslweek.

Endocrine and Menstrual Function

It is unclear whether the hormonal adaptations associated with exercise training are directly linked to the development of menstrual abnormalities. The normal rhythm of the menstrual cycle requires the precise stimulation of ovarian hormone secretion by the pulsatile release of the pituitary gonadotrophic hormones LH and FSH (15). The levels of estrogen, progesterone, LH, and to a lesser extent FSH are characteristically reduced in the intensively training amenorrheic athlete (1, 13). During the amenorrheic state, these athletes have estrogen levels similar to those found in postmenopausal women (13), suggesting decreased steroid synthesis at the ovary. Amenorrheic subjects also exhibit a decrease in LH pulse frequency, suggesting that the highest volume of endurance training will have a more advanced inhibitory effect on the hypothalamus (15).

Prior to the intervention, the amenorrheic subject displayed a hormonal profile typical of a well-trained endurance athlete with menstrual dysfunction. In comparison to her eumenorrheic counterparts, the amenorrheic subject had baseline serum levels of LH, estrogen, and progesterone that were dramatically reduced, while cortisol levels remained elevated. This hormonal profile suggests that the hypothalamic-pituitary+varian (HPO) axis was inhibited at both the hypothalamic and ovarian levels, as evidenced by the reduced levels of serum LH, estrogen, and progesterone. The elevated level of cortisol suggests that the hypothalamic-pituitary-adrenal (HPA) axis was being stimulated and possibly was contributing to the downregulation of the reproductive axis.

Increased basal serum cortisol levels have been previously reported in amenorrheic athletes compared with eumenorrheic athletes and normal-cyclic, nonathletic women (15,23). These findings suggest that increased glucocorticoid levels are important in the development of athletic menstrual dysfunction and may serve as a marker for altered interactions between the HPA and HPO axes


(15). Furthermore, it has been suggested that hypercortisolemia may inhibit the transition from amenorrhea to normal menstrual function, consequently increasing the risk of a prolonged acyclic state (5). Amenorrheic athletes who reduce their cortisol levels to normal range (7-24 pgldl) have been shown to spontaneously regain menstrual function within 6 months, while those with chronically elevated cortisol levels remain amenorrheic (5).

The 15-week intervention program appears to have had a stimulatory effect on the HPO axis as evidenced by the increase in serum levels of fasting LH. These LH changes may reflect the early stages of hypothalamic recovery, preceding the resumption of normal menstrual function. Furthermore, the reduction in serum cortisol suggests that the intervention was effective in downregulating the HPA axis and its possible inhibitory effects at the hypothalamus, anterior pituitary, and ovaries. However, many factors may contribute to the reduction in serum cortisol. Cortisol is typically classified as a "stress hormone" and may become elevated during times of metabolic, physiological, or psychological stress. Al- though the intervention reduced the metabolic stress associated with a negative energy state, the reduced psychological stress associated with improved performance must also be considered as a contributing factor.

These hormonal changes contrast with those seen in the eumenorrheic athletes, who displayed a reduction in early follicular phase LH from baseline to Week 15 (7.9 + 6.5 to 5.7 + 1.3 mIU/ml) and little change in serum cortisol levels. Furthermore, it appears that 1 eumenorrheic athlete had become anovula- tory by the end of the 15-week competitive season. She did not display an increase in urinary levels of LH, as determined through the use of an ovulation detection kit on Days 10-19 of her menstrual cycle. This suggests that while the amenorrheic subject was moving toward better energy balance and reduced reproductive axis inhibition, the eumenorrheic subjects were becoming overtrained and were entering the preliminary stages of menstrual dysfunction. In particular, the reduction in LH may suggest that the eurnenorrheic subjects were-beginning to exhibit hypothalamic dysfunction and inhibition of the reproductive axis.

Body Composition

Although hydrodensitometry is often regarded as the "gold standard" for determining body composition, it does not take into account the effect that reduced BMD may have on the density of lean body mass (4). Consequently, hydrodensitometry may not always be the appropriate technique for assessing body composition in the female athlete population, especially in individuals who are amenorrheic or at risk for osteoporosis. For these reasons, body composition was measured in the amenorrheic athlete by both hydrodensitometry and DEXA to provide a better assessment of percent body fat.

In the amenorrheic subject, no differences in percent body fat were found between the two techniques. A possible explanation as to why hydrodensitometry did not overpredict our amenorrheic athlete's percent body fat is her relatively high BMD. As a possible result of her active lifestyle, which included several years of gymnastics and a reported history of high dietary calcium intake, her bone density remains above the age-expected norm despite her 14-month amenorrheic history. It is important to emphasize that although the arnenonheic athlete's BMD was above the age-expected norm, she still had a history of tibia1 stress fractures.


The most widely assumed mechanism concerning athletic amenorrhea has been that a critical ratio of body fat to body weight is necessary for the onset and maintenance of menstrual cycles (9). Because some athletes with low levels of body fat remain cyclic, some higher fat athletes are amenorrheic, and some athletes regain their menstrual cycles with no change in body weight, it is difficult to accept the proposed body composition mechanism (21). Thus, there appears to be no critical level of body fat necessary for normal menstrual function applicable to all athletes. Although an amenorrheic and a eumenorrheic athlete may have the same percent body fat, it is possible that the critical difference is each individual's body fat distribution rather than her absolute percentage of body fat. Brownell suggests that the depletion of regional fat stores that accumu- late below the waist in the mature female can signal inadequate energy reserves for lactation a ~ d pregnancy, thus shutting down reproductive function (2).

DEXA provided the opportunity to evaluate the changes in total and regional body fat. After 15 weeks, the amenorrheic subject increased truncal region body fat by 6.2% and had gains in her leg and arm regions of 4.6 and IS%, respectively. This relatively large increase in truncal body fat supports the hypothesis that the onset of menstrual dysfunction may be associated with changes in regional body fat distribution, particularly around the reproductive organs and trunk. Although the eumenorrheic athletes showed minimal losses in total body fat (-0.4%), the largest regional losses occurred in the trunk (-4.3%) followed by the arms and legs (-2.9% and -1.2%, respectively).

Conclusion

The results of this case study suggest that the 15-week diet and training intervention program brought the amenorrheic subject into better energy balance, as evidenced by the increase in body weight. The dramatic increase in serum LH suggests that the intervention removed the inhibition on the reproductive axis at the level of the hypothalamus and initiated some of the hormonal changes required for the resumption of menstrual cyclicity. This is further supported by the resumption of menstruation that occurred in the athlete after following the intervention program for an additional 3 months.

Perhaps most striking, at least from the athlete's point of view, was the dramatic increase in performance that occurred when she improved her overall energy balance. We hope the intervention program's positive effect on performance will change the mindset of coaches and athletes. Menstrual dysfunction should not be viewed as an indicator of appropriate training levels, but rather as an indication of inappropriate training levels and a significant threat to optimal performance and health. Unlike hormonal therapy, which can have negative side effects, our modifications in diet and training led to better metabolic balance and a subsequent transition from overtraining to peak performance. These results suggest that nonpharmacological modes of treatment for athletic amenorrhea can contribute to the resumption of a more normal hormonal profile and menstrual status in amenorrheic athletes and can improve performance.

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Acknowledgments

We are extremely grateful to Reebok for funding this study and to the Gatorade Sport Science Institute for their generous donation of the product. We also gratefully acknowledge the technical assistance of Daisy Steiner, M.S., and Kelly Enders, R.N. The cooperation and dedication of the coaches and cross-country team members at Mesa Community College were essential to the completion of this study.

Manuscript received: May 29, 1995 Accepted for publication: November 21, 1995

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