Energy balance
Intense physical exercise combined with low energy intake (common in ballet dancers and athletes) delays menarche and causes amenorrhea by preventing the attainment of the critical lean mass-to-fat ratio required for reproductive function.
Female athletes, especially those in aesthetic or endurance sports, are at high risk for amenorrhea if they do not consume enough calories to support both training and the maintenance of a critical body fat percentage. Delayed menarche and irregular cycles are signs that energy intake is insufficient for reproductive health, not just 'part of training'.
If a critical level of fat in relation to the lean body mass is necessary for successful reproduction, high energy outputs, in addition to low nutritional intake, would be expected to affect menarche and mature female reproductive ability. This effect is found: ballet dancers... and athletes do have a high incidence of irregular cycles and amenorrhoea.
Why this rating
Supported by observational data on athletes and dancers showing delayed menarche and high amenorrhea rates.
Source
BODY FAT, PUBERTY AND FERTILITY
Rose E. Frisch · Biological reviews/Biological reviews of the Cambridge Philosophical Society · 1984
DOI 10.1111/j.1469-185x.1984.tb00406.x
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