title: [Physical activity and reproductive health].
abstract: BACKGROUND
  The purpose of this article is to review the present knowledge about physical activity and reproductive health.
  
  
  METHODS
  Medline and manual search for articles related to exercise and menstrual function, and exercise and pregnancy were performed.
  
  
  RESULTS
  Repetitive intensive exercise with increased stress hormone utilisation seems to partly explain the disturbances in the hypothalamic-pituitary-adrenal axis. The prevalence of menstrual irregularities is higher among athletes who participate in sports in which leanness is considered important for performance. Most of the studies concerning exercise-induced amenorrhoea have focused on low body weight and low fat ratio of body weight. However, energy drain and nutrient deficiency have been found to be important variables explaining menstrual irregularity in athletes. Loss of bone mass is related to menstrual irregularities hence it is important that menstrual irregularity not is considered a "normal" aspect of being an athlete. There are a number of positive effects and a few hypothetical risks related to exercise during pregnancy. There are no clinically controlled studies allowing us to draw conclusions about the effect of intensive training during pregnancy.
  
  
  CONCLUSIONS
  Physically active women should be aware of the importance of sufficient energy intake to keep their regular menstrual cycle. Moderate exercise during pregnancy is recommended.
authors.affiliation: Avdeling for idrettsmedisin Norges idrettshøgskole Postboks 4014 Ullevål Stadion 0806 Oslo. jorunn@nih.no
authors.forename: J
authors.initials: J
authors.lastname: Sundgot-Borgen
mesh_terms: D000568:Amenorrhea / Q000209:etiology / Q000517:prevention & control; D001265:Athletic Injuries / Q000150:complications* / Q000503:physiopathology; D015519:Bone Density; D005314:Embryonic and Fetal Development; D002149:Energy Intake; D015444:Exercise; D001068:Feeding and Eating Disorders / Q000150:complications / Q000503:physiopathology; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D008599:Menstruation Disturbances / Q000209:etiology / Q000517:prevention & control; D011247:Pregnancy / Q000502:physiology*; D014891:Weight Lifting; D015431:Weight Loss