Most pregnant women can exercise safely if they don't exercise so vigorously that they drive their body temperatures too high.

It is almost impossible for a pregnant women to exercise so vigorously that the baby's brain is deprived of oxygen, but lack of calories and high body temperature can damage the baby's brain. Eighty percent of the energy used to power muscles is lost as heat, so the harder you exercise, the higher your temperature rises, but I know of no reports of brain damage from a mother exercising during pregnancy.

Ingrid Kristianson, the former world record holder, gave birth to a healthy baby after winning the Houston Marathon (fastest woman) when three months pregnant. Sharon Wood climbed Mt. Everest while pregnant. Pregnant women who exercise vigorously during pregnancy give birth to smaller, but apparently healthy babies. Pregnant women can probably exercise safely if they don't raise their temperatures too high and avoid dangerous exercises such a kick boxing and sky diving.

Checked 9/3/05

Get our newsletter