Various types of physical activity can influence fertility and pregnancy outcome. By negatively altering the hormone milieu, menstrual cycles, ovulation, and egg and sperm quality, excessive or insufficient exercise may lead to diminished fertility. Women who regularly exercise before and during the pregnancy have better pregnancy outcomes with reduced risks of complications.

Females who exercise heavily may have absent ovulation leading to low oestrogen levels and possibly bone loss (osteopenia or osteoporosis). Low body mass index (BMI) is associated with oligomenorrhea (scanty menstruation) or amenorrhea (lack of ovulation and periods). Likewise, lack of exercise and being overweight may also impact ovulation and egg quality by increasing insulin resistance.

Polycystic ovary syndrome (PCOS) is the common hormonal disorder in reproductive aged group, which is commonly associated with obesity and ovulation dysfunction. Obese women with PCOS have increased risk of having miscarriages, but regular exercise with dietary modifications can lead to better fertility outcomes. It has been documented that reducing 5-10% of total body weight along with exercise is sufficient enough to restore normal ovulation.

Exercise also has great impact on the management of stress, which is common in women trying to conceive. Stress leads to the release of cortisol and catecholamines (adrenaline and noradrenaline) that results in narrowing of blood vessels and elevated sugar levels, metabolic rate, pulse and blood pressure. By generating endorphins, enhancing circulation, preventing the release of excessive cortisol, and limiting the release of catecholamine, regular exercise can decrease such harmful consequences. Overall, the womb and ovaries receive more blood, which improves the quality of the oocytes and the success of embryo implantation.