Working out increases growth hormone, which is key to healthy body composition and increases insulin sensitivity, which helps regulate blood sugar, Keay says. It triggers the release of dopamine and serotonin, well known for their mood-boosting effects. Exercise also boosts estrogen1, a reproductive hormone whose decline is to blame for many menopause symptoms, and testosterone, which supports everything from bone health to libido. Several studies have demonstrated that regular exercise can relieve menstrual pain2, which can at least in part be explained by increased progesterone, which has anti-inflammatory effects.