Jacalyn J. Robert-McComb, PhD Fellow of the American College of Sports Medicine

1. CHAPTER 26 - Nutritional Guidelines and Energy Needs for the Female Athlete-Determining Energy and Nutritional Needs to Ameliorate Functional Amenorrhea Caused by Energy Imbalance Jacalyn J. Robert-McComb, PhD Fellow of the American College of Sports Medicine

2. Learning Objectives • Describe the energy availability hypothesis and functional amenorrhea; • Describe the energy and nutritional intake estimations; • Describe nutritional guidelines for the female athlete; and • Describe the importance of hydration before, during, and after exercise.

3. Energy Drain and Menstrual Dysfunction • The prevalence of amenorrhea is elevated in women who restrict their diets and are intensely physically active (Torstveit & Sundgot-Borgen, 2004). • Warren was the first to suggest that menstrual disorders in female athletes are disrupted by an energy drain (Warren, 1980).

4. Disruption of Gonadotropin Releasing Hormone (GnRH) • Winterer et al. (1984) proposed the hypothesis that failure to provide sufficient metabolic fuels to meet the energy requirements of the brain causes an alteration in brain function that disrupts the Gonadotropin releasing hormone (GnRH) pulse mechanism.

5. Reproductive Function • Reproductive function critically depends on the pulsatile release of GnRH from GnRH neurons in the arcuate nucleus of the hypothalamus and on the consequent pulsatile release of lutenizing hormone (LH) from the pituitary (Loucks & Thuma, 2003).

7. Suppression of LH • In the athletic female, energy drain can occur by either not taking in enough calories to meet the metabolic needs of the body or by over exercising and not compensating for the energy cost of the exercise by taking in additional calories. Hence LH pulsatility can be suppressed by a combination of strenuous exercise and caloric restriction (Loucks et al., 1998) if energy availability falls below a critical threshold.

8. Functional Amenorrhea • This has been termed "functional amenorrhea", because the problem is a functional problem (altered hormonal patterns), rather than an anatomical problem (Loucks & Thuma, 1984). The restoration of normal menstrual cycling has been demonstrated to reoccur when the individual's threshold for energy availability is sequentially met (Locks & Callister, 1993).

9. Threshold of Energy Availability • Loucks and Thuma (2003) found that LH pulsatility was disrupted abruptly at a threshold of energy availability not higher than 30 kcal/kg LBM.d in regularly menstruating, habitually sedentary young women of normal body composition. • They also found that the disruptive effects of sub threshold energy availability were bimodal, with substantially larger effects occurring in subjects with the shortest luteal phases.

10. Loucks and Thuma (2003) • Not all females have the same threshold for energy- availability; but if this threshold falls below a critical threshold, hormonal alterations will result. • The restoration of normal menstrual cycling has been demonstrated to reoccur when the individual's threshold for energy availability is sequentially met.

11. Estimating Energy and Nutritional Intake • Studies consistently show that female athletes are not consuming enough energy to support their activity levels (Pate et al., 1990). • Research with elite female swimmers, using the doubly labeled water technique, noted that total daily energy increased to 5, 593 kcal daily during high-volume training. • However their intake averaged only 3,136 kcal, implying a negative energy balance (Trappe, 1997)

12. Estimated Calorie Requirements (in Kilocalories) for Specific Age Groups at Three Levels of Physical Activitya using the Institute of Medicine Equations

13. Activity Levels • Sedentary means a lifestyle that includes only the light physical activity associated with typical day-to-day life. • Moderately active means a lifestyle that includes physical activity equivalent to walking about 1.5 to 3 miles per day at 3 to 4 miles per hour, in addition to the light physical activity associated with typical day-to-day life. • Active means a lifestyle that includes physical activity equivalent to walking more than 3 miles per day at 3 to 4 miles per hour, in addition to the light physical activity associated with typical day-to-day life.

14. Example of Specific Recommendations for Physically Active Females from 19-30 years from the US Department of Health and Human Services based on 2,400 calorie pattern.

15. Recommendations for Macronutrients and Energy Intake for the Physically Active Female • The Food Guide Pyramid provides broad recommendations for healthful nutrition for the physically active individual. • Diets should emphasize fruits and vegetables, cereals and whole grains, nonfat and low-fat dairy products, legumes, nuts, fish, poultry, and lean meats. • Female athlete’s diet have been found to be low on iron, calcium, zinc, vitamin B6, and folate.

16. Continued • Good sources of folate include fortified breakfast cereal, soy flour, beans, wheat germ, chicken and beef liver, papaya (see http://www.swedish.org/15374.cfm) • Studies consistently show that female athletes are not consuming enough energy to support their activity levels. • Low energy and nutrient intake places athletes at greater risk for nutrition related disorders such as amenorrhea, osteoporosis, iron deficiency anemia, and eating disorders.

17. Fat Intake • Fat intake should not be restricted provided that the fat intake is low in saturated fats and trans fats; • There is no benefit in consuming a diet with less than 15% of energy from fat as compared to 20-25%. • Acceptable lipid intakes for physically active individuals ranges from 20 and 35% of caloric intake.

18. Carbohydrate Intake • General recommendations for carbohydrates range between 6-10g/ kg of body mass per day. • This range represents approximately 55-65% carbohydrate intake. • Carbohydrates should be predominantly starches from fiber-rich, unprocessed grains, fruits and vegetables.

19. Protein Requirements • Protein requirements are slightly increased in highly active people. • Protein requirements for endurance athletes are 1.2-1.4 g/kg body mass per day, whereas those for resistance and strength trained athletes may be as high as 1.6 to 1.7 g/kg of body weight per day. • According to the Dietary Reference Intakes, acceptable macronutrient distribution ranges of protein for adults are 10-35%.

20. The Importance of Hydration Before, During, and after Exercise • ACSM (1996) and NATA (Casa et al., 2000) recommend drinking 400-600 mL (16 to 24 oz) of fluid 2-3 h before the exercise. • During exercise, optimal hydration can be facilitated by drinking 150-350 mL (6 to 12 0z) of fluid at 15-20-min intervals, beginning at the start of the exercise. • Consuming up to 150% of the weight lost during an exercise session may be necessary to cover loses in sweat and urine excretion (Shirreffs et al. , 1996).

21. How Exercise Nutritionists Can Help Female Athletes Maintain Energy Balance • Athletes should be educated about energy requirements for their sport and the role of food in fueling the body. • Female athletes should be educated about the Female Athletic Triad and the long term health consequences of inadequate energy intake. • Unrealistic weight and body composition goals should be discouraged.

22. Body size and composition of an athlete should be assessed for the determination of an appropriate weight and composition for the sports in which she participates. • Minimum body composition for good health for the female athlete is 12%. • Provide the athlete with nutritionally sound techniques for maintaining an appropriate body weight and composition without the use of severe diets or nutritionally unbalanced macronutrient choices.