The effect of physical activity on fertility: a mini-review said:
Our review of the literature suggests that recommendations regarding PA while trying to conceive should be tailored on the basis of specific patient characteristics. Specifically, overweight and obese women with PCOS should be encouraged to engage in vigorous aerobic exercise or resistance training to experience their insulin-sensitizing effects; similar recommendations can likely be applied to lean women with PCOS, although future research is needed to confirm this. In the case of women undergoing assisted reproduction for other diagnoses, exercise likely has little to no impact on treatment outcomes—individuals can therefore continue their regular exercise regimen throughout treatment.
However, in the case of healthy women who are trying to conceive, the potential for regular vigorous exercise to negatively impact fertility should be considered. That is, the exercise regimen of women presenting for evaluation of subfertility should be assessed, and the presence of anovulation and/or a luteal phase defect caused by vigorous exercise should be considered. When anovulation and/or a luteal phase defect are detected, the patient could be encouraged to increase her caloric intake to avoid an exercise-induced deficit or, when necessary, to replace vigorous exercise with moderate-intensity exercise for a time to see whether menstrual cycles normalize. However, in light of the considerable mental and physical health benefits of regular exercise, we would advocate against indiscriminately discouraging highly active women from engaging in vigorous exercise while trying to conceive.