Eating Disorders and Sports Performance

Although many athletes initially experience an improvement in sports performance with weight loss, this improvement is generally short lived if it was due to a drastic reduction in food intake. A major decrease in food consumption depletes energy and can be indicative of an eating disorder. Lower plasma volume, impaired thermoregulation, and lower glycogen storage are all associated with eating disorders and can lower the levels of anaerobic and aerobic endurance.^20,21

In addition, lowered food intake also predisposes athletes to multiple micro nutrient deficiencies that can lower athletic performance and increase the risk of injury. This is evidenced when examining the abnormal menstrual patterns that often accompany eating disorders. Females who have stopped menstruating have lower levels of calcium in their bones, increasing their risk for stress fractures. The menstrual abnormalities correlate to a negative balance of energy and are also associated with a lower resting-energy expenditure, which is typically the result of a decreased metabolic rate and lean mass.²²

Body composition can be a useful tool in helping the athlete and coach understand the changes that are occurring as a result of training and nutrition factors. Health professionals involved in obtaining body composition data should focus on using the same technique with the same prediction equations to derive valid comparative data over time. Care should be taken that body composition values are used constructively as part of the athlete's total training plan. Ideally, the emphasis should be on a periodic (semiannually or quarterly) monitoring of the athlete's body composition to determine change of both the lean and fat mass. Many athletes are sensitive about body fat, so care should be taken to use body composition values in a way that enables their constructive use in an athlete's general training plan. Athletes suspected of having an eating disorder should be quickly assessed and treated if necessary. It is likely that helping young athletes understand appropriate nutrition strategies for attaining a desirable body profile, weight, strength, and endurance will help reduce future eating disorder risk.