title: Athletic activity and hormone concentrations in high school female athletes.
abstract: BACKGROUND
  Physical activity may affect the concentrations of circulating endogenous hormones in female athletes. Understanding the relationship between athletic and physical activity and circulating female hormone concentrations is critical.
  
  
  OBJECTIVE
  To test the hypotheses that (1) the estradiol-progesterone profile of high school adolescent girls participating in training, conditioning, and competition would differ from that of physically inactive, age-matched adolescent girls throughout a 3-month period; and (2) athletic training and conditioning would alter body composition (muscle, bone), leading to an increasingly greater lean-body-mass to fat-body-mass ratio with accompanying hormonal changes.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Laboratory and participants' homes.
  
  
  METHODS
  A total of 106 adolescent girls, ages 14-18 years, who had experienced at least 3 menstrual cycles in their lifetime.
  
  
  METHODS
  Participants were prospectively monitored throughout a 13-week period, with weekly physical activity assessments and 15 urine samples for estrogen, luteinizing hormone, creatinine, and progesterone concentrations. Each girl underwent body-composition measurements before and after the study period.
  
  
  RESULTS
  Seventy-four of the 98 girls (76%) who completed the study classified themselves as athletes. Body mass index, body mass, and fat measures remained stable, and 17 teenagers had no complete menstrual cycle during the observation period. Mean concentrations of log(estrogen/creatinine) were slightly greater in nonathletes who had cycles of <24 or >35 days. Mean log(progesterone/creatinine) concentrations in nonathletes were less in the first half and greater in the second half of the cycle, but the differences were not statistically significant.
  
  
  CONCLUSIONS
  A moderate level of athletic or physical activity did not influence urine concentrations of estrogen, progesterone, or luteinizing hormones. However, none of the participants achieved high levels of physical activity. A significant number (17%) of girls in both activity groups were amenorrheic during the 3-month study period.
authors.affiliation: MedSport and Departments of.
authors.forename: Edward M
authors.initials: EM
authors.lastname: Wojtys
authors.forename: Mary L
authors.initials: ML
authors.lastname: Jannausch
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Kreinbrink
authors.forename: Siobán D
authors.initials: SD
authors.lastname: Harlow
authors.forename: MaryFran R
authors.initials: MR
authors.lastname: Sowers
mesh_terms: D000293:Adolescent; D056352:Athletes / Q000193:education; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D015331:Cohort Studies; D004958:Estradiol / Q000652:urine*; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000652:urine*; D008597:Menstrual Cycle / Q000502:physiology; D009043:Motor Activity / Q000502:physiology*; D011374:Progesterone / Q000652:urine*; D012572:School Health Services; D012574:Schools; D013177:Sports / Q000502:physiology*; D055815:Young Adult
chemical_list: D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone
keywords: anterior cruciate ligament; estrogen; exercise physiology; menstrual cycle