Chapter 682 Female Athletes
Menstrual Problems and the Risk of Osteopenia
Overtraining in young women can be associated with its effect on reproductive function and bone mineral status especially when combined with calorie restriction (Chapters 26 and 110).
The majority of bone mass is acquired by the end of the 2nd decade (Chapter 698). About 60-70% of adult bone mass is genetically determined, and the remaining is influenced by 3 controllable factors: exercise, calcium intake, and sex steroids, primarily estrogen. Exercise promotes bone mineralization in the majority of young women and is to be encouraged. In girls with eating disorders and those who exercise to the point of excessive weight loss with amenorrhea or oligomenorrhea, exercise can be detrimental to bone mineral acquisition, resulting in reduced bone mineral content, or osteopenia.
Three eating disorders can occur in the context of amenorrhea: anorexia nervosa, manifesting as weight <85% of estimated ideal body weight with evidence of starvation manifesting as bradycardia, hypothermia, and orthostatic hypotension or orthostatic tachycardia; bulimia nervosa, manifesting as reduced or normal weight with wider fluctuations of weight than would be expected based on the reported caloric intake and exercise; and eating disorder not otherwise specified, with some of the features of either anorexia or bulimia nervosa, yet not meeting all criteria from the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, for diagnosis of either (Chapter 26). The third type of eating disorder is sometimes diagnosed as an atypical eating disorder. Multiple symptoms and methods can occur together, from unhealthy caloric or fat restriction to bingeing and purging. Clues to the problem are weight loss, food restriction, depression, fatigue and worsened athletic performance, and preoccupation with calories and weight. The athlete might avoid events surrounding food consumption or might hide and discard food. Signs and symptoms include fat depletion, muscle wasting, bradycardia worsened from baseline, orthostatic hypotension, constipation, cold intolerance, hypothermia, gastric motility problems, and, in some cases, lanugo. Electrolyte abnormalities can lead to cardiac dysrhythmias. Psychiatric problems (depression, anxiety, suicide risk) are of higher incidence in this population.
American Academy of Pediatrics Committee on Sports Medicine and Fitness. Medical concerns in the female athlete. Pediatrics. 2000;106:610-612.
Birch K. Female athlete triad. BMJ. 2005;330:244-246.
Greydanus DE, Patel DR. The female athlete before and beyond puberty. Pediatr Clin North Am. 2002;49:553-580.
Nemet D, Eliakim A. Pediatric sports nutrition: an update. Curr Opin Clin Nutr Metab Care. 2009;12(3):304-309.
Soligard T, Myklebust G, Steffen K, et al. Comprehensive warm-up programme to prevent injuries in young female footballer’s: cluster randomized controlled trial. BMJ. 2009;338:95-98.
Warren MP, Chua AT. Exercise-induced amenorrhea and bone health in the adolescent athlete. Ann N Y Acad Sci. 2008;1135:244-252.