For ladies training in high intensity sports that result in extremely low body fat, e.g. dancing and gymnastics or endurance sports like running and triathlons, there is a risk of disruption of the menstrual cycle and subsequent impact on fertility. The occurrence of menstrual disturbances occurs in 10-20% of athletes compared to 5% in the general population. This can include irregular periods (oligomenorrhea) or absence of periods (amenorrhea).
The contributing factors are thought to be low intake of calories, high output of energy, and psychological stress. These factors all lead to reduced energy available for the body and in these cases the body chooses to prioritise systems more important for survival, leaving less resources for the reproductive system.
In most cases this can be reversed and normal menstruation will resume with an increase in body fat, reduction in intense exercise and less stress. Long term fertility is usually unaffected. If menstruation doesn’t resume, and pregnancy is desired, referral for gynaecological assessment may be necessary.