Effect of Athletic Activity on Hormone Levels in High School Female Athletes

OBJECTIVES: Circulating endogenous hormone levels may affect the susceptibility of female athletes to anterior cruciate ligament (ACL) injuries. This study tested the hypotheses that (1) the estradiol-progesterone profile of high school females participating in training, conditioning, and competition differs significantly from that of physically inactive age-matched females over a 3-month period; and (2) athletic training/conditioning alters body composition (muscle, bone), leading to an increasingly greater lean body mass to fat mass ratio and accompanying hormone change. METHODS: One-hundred six women, ages 14-18 years, were prospectively monitored over a 13-week period with weekly physical activity assessments and 15 urine samples for estrogen (E1c), luteinizing hormone (LH) creatine (Cr), and progesterone (PdG) levels. Each underwent lower extremity strength tests and body composition measurements, both prior to and after the study period. RESULTS: Seventy-four of the 98 women who completed the study classified themselves as athletes. Body-mass index, weight and fat measures remained stable over the course of the study. Seventeen women had no complete menstrual cycle during the observation period. Mean levels of log(E1c/Cr) were slightly higher in nonathletes in cycles <24 or >35 days. Mean log(PdG/Cr) levels in nonathletes were lower in the first half and higher in the second half of the cycle, but the differences were not statistically significant. CONCLUSION: In this cohort of high school females, the level of athletic or physical activity did not influence urine concentrations of estrogen, progesterone or luteinizing hormones. A significant number (17%) of women in both groups were amenorrheic during the 3-month study period.