For most pregnant women, exercise is the last thing on their minds. After all, keeping slim while you're expecting isn't exactly the top priority — rather, it's making sure your baby gets enough nutrients to grow. But in a small new study, researchers at the University of Auckland in New Zealand report that a mother's regular aerobic exercise may be good for a growing fetus' health — and may even help a baby get a healthier start in life.Researchers asked some women to exercise on a stationary bicycle for at least 40 minutes per session, up to five times each week, starting in the 20th week of pregnancy; the other women were not specifically asked to exercise. When the two groups and their babies were compared, the team found that women who bicycled regularly gave birth to babies who were on average 150 g (about 5 oz.) lighter than those born to the nonexercising mothers. In both groups, however, the babies were of healthy weight, and there was no difference in the mothers' weights.
