Body temperature changes rhythmically throughout the menstrual cycle, peaking during the luteal phase in response to the surge in progesterone. Progesterone acts on the brain's hypothalamus (the temperature control center), which increases set-point temperature. A higher body temperature during the luteal phase makes it harder to run in the heat during this phase, as runners don't begin sweating to dissipate heat until they have reached a higher body temperature. So avoid long races in the heat during the luteal phase of your cycle.
Pregnancy and Running
For most female runners, running through the first two trimesters is completely healthy. Frequent complaints of pregnancy, including nausea, heartburn, insomnia, varicose veins and leg cramps are reduced in women who remain active during their pregnancies. Exercise during pregnancy has also been associated with a reduced risk of developing certain obstetrical complications, including preeclampsia, pregnancy-induced hypertension and gestational diabetes. There are a few medical conditions that may prohibit you from running and racing while pregnant: significant heart and lung disease, persistent bleeding in the second and third trimesters, and ruptured membranes.
Female Metabolism: An Advantage for Distance Running
Women rely more on fat and less on carbohydrate while running at the same pace. Because humans' carbohydrate stores are limited, the difference in metabolism between the sexes gives female runners an advantage for very long endurance activities, during which there is a greater need to conserve carbohydrate and use more fat because of the slower pace.race.