Back in the 19th century, pregnancy was considered a delicate condition that required confinement to the chaise longue in one's private sitting room. Today's wisdom is quite the opposite: Physical activity is not only harmless to you and your baby, it can do you both good.

A woman who exercises is bound to weather the physical stresses and strains of pregnancy better. Moreover, working out helps you fight fatigue more effectively and motivates you to eat more nutritiously. The endorphins (feel-good proteins produced by the pituitary gland) released during exercise can give you a more chipper outlook even as your hormones take you on a roller coaster ride of mood changes. And by strengthening back and abdominal muscles, you can help ease back pain, a common complaint as ligaments stretch and your weight load increases.

Some ob-gyns have also found that expectant mothers who exercise regularly have an easier or shorter labor. In one study, moms who worked out three times a week had 21 percent fewer cesareans and recovered more quickly. (Don't let the dream of a perfect delivery be your only motivation, however: The finding that prenatal exercise makes for better labor remains controversial, since many factors influence the length and course of labor.) Whatever the nature of your delivery turns out to be, it certainly stands to reason that mothers accustomed to physical exertion are better prepared for the rigors of childbirth. In terms of physical stress and oxygen consumption, the average labor is equivalent to jogging 12 miles!

One thing you shouldn't use an exercise program for right now, of course, is weight control. Losing weight by any means is not recommended during pregnancy.

---