Many female athletes and parents worry about the effects of exercise on the menstrual cycle. In the State of New York, girls who have not yet begun to menstruate are prohibited from competing in interscholastic athletic events. Moderate exercise has several benefits for women; however, intense exercise can delay the onset of a girl's menstrual period. This delay has several possible mechanisms and may not have a long lasting on the ability of women to bear children.
Benefits of Exercise
When performed in moderation, exercise can have several benefits for menstruating women. Women who exercise regularly and participate in physical activity like jogging report that they have less premenstrual tension, discomfort and shorter periods since taking up this activity. Regular exercise helps keep your body weight in a healthy zone, which is known to permit less intense menstrual cycles.
Delay of Menarche
Intense exercise and athletic training programs, such as those undergone by professional ballerinas and swimmers, have been known to delay the onset of menarche in young women. This phenomena is also called primary amenorrhea. A study cited by the New York Times estimates that each year of training before menarche delayed the onset of girl's first periods by five months.
Mechanisms for Delay
The delay in onset of a girl's menstrual period has been speculated to be the result of hormonal changes. A study published in the journal of "Medicine and Science in Sport and Exercise" revealed that athletes experiencing amenorrhea had abnormal levels of reproductive hormones. Possible hormones responsible for the delay include GnRH and luteal hormone.
Later Effects
A study cited by "The New York Times" indicates that delayed onset of a girls period due to strenuous exercise does not negatively affect the ability of these girls to have children later in life. In addition, this delay may reduce susceptibility to cancers of the breast and reproductive system because susceptibility to these cancers seems to be directly related to the total number of ovulatory periods in a woman's lifetime.
References
- "The New York Times"; Personal Health; Effects of Exercise on Menstruation; Jane E. Brody; September 1982
- "Medicine and Science in Sports and Exercise"; Effects of Exercise Training on the Menstrual Cycle: Existence and Mechanisms; AB Loucks: June 1990;
- Healthdesk: Exercise and Menstruation
- "The New York Times"; New Studies Link Exercise to Delays in Menstruation - and Less Cancer; Walter Sullivan; February 1988
