ATHLETES WITH IRREGULAR PERIODS TAKE ESTROGEN
Report #7245
Having irregular periods increases a woman's chances of suffering broken bones, no matter how much she exercises.
A study in the Scandinavian Journal of Medicine and Science in Sports shows that 24% of competitive female long distance runners have irregular periods (1). Most lack the female hormone estrogen and will suffer severe loss of bone, no matter how much they exercise. A recent study from the University of Washington shows that most will not regain the amount of calcium that they lose from their bones (2). Indeed most studies show that exercise will not stop bone loss caused by lack of estrogen before ar after the menopause (3). The women most likely to have exercise-associated irregular periods are those who had irregular periods before they started to train for athletic competition. Exercise-associated irregular periods are restricted to women who compete and train at a high level, but have nothing to do with how much they train. Previous studies show that regular exercise does not increase a woman's chances of having irregular periods. Most of the women with irregular periods are obsessed with restricting food. When women with exercise-associated irregular periods eat more food, their periods usually return to normal. So, exercise-associated irregular periods is caused by not eating enough calories, not by exercising.
By Gabe Mirkin, M.D., for CBS Radio News
1) SE Tomten. Prevalence of menstrual dysfunction in Norwegian long-distance runners
participating in the Oslo Marathon. Scandinavian Journal of Medicine & Science in
Sports. 1996(June):6(3):164-171. 2) Keen, A.D.; Drinkwater, B.L. Irreversible bone loss in former amenorrheic athletes.
Osteoporosis International. 1997;7(4):311-315. BL Drinkwater/Pacific Med Ctr/Dept Med/1200
12TH Ave S/Seattle, WA 98144 USA. 3) Berard, A.; Bravo, G.; Gauthier, P. Meta-analysis of the effectiveness of physical
activity for the prevention of bone loss in postmenopausal women. Osteoporosis
International. 1997;7(4):331-337. A Berard/Mcgill Univ/Jewish Gen Hosp/Smbd/Fac Med/Dept
Epidemiol & Biostat/Montreal/Pq H3A 2T5, Canada.
Reported 10/6/97; Checked 9/5/05