Curtis Harwell & Kim Duke Discuss Pregnancy and Being Fit

Exercise is not a process that needs be eschewed or prevented during pregnancy," says Dr. John Botti, director of maternal-fetal medicine at Penn State Geisinger Health System, who studied the effects of exercise on moderately conditioned pregnant women. "Reasonably performed exercise doesn't appear to cause harm, and may, in fact, have benefits."

The key is finding a reasonable level, and that depends largely on the shape you were in before, the activities your body was comfortable with, and your health during pregnancy. Always check with your doctor or midwife first, but here's food for thought for the novice and the enthusiast, as well as some basic dos and don'ts.

The Novice: Walking and Water Spell R-E-L-I-E-F

"Only 20% to 30% of the population exercises on a regular basis, so the typical pregnant woman hasn't exercised prior to pregnancy," says Bonnie Berk, creator of MOTHERWELL, a pre- and postnatal fitness program offered throughout the United States and abroad.

Still, it's not too late for pregnant women who haven't been consistent exercisers to start now. Although hard data on the value of prenatal exercise isn't as well-documented for unfit women as for fit ones, experts like Berk have seen firsthand the difference that exercise can make, even for couch potatoes.