If you are pregnant and overweight, don’t count on exercise to transform you into the model of health while awaiting your bundle of joy.
That’s the latest from a study of heavy women in Brazil that found beginning an exercise or diet program during pregnancy isn’t as helpful as starting it before becoming pregnant.

According to the U.S.-based National Institutes of Health, overweight women should gain, on average, about 15 to 25 pounds during pregnancy. Obese women, just 11 to 20.

In the study, most overweight and obese women gained more than the recommended amount of weight during pregnancy, even with exercise. Gaining too much weight during pregnancy can increase the chances of having a large baby and requiring a Cesarean section. Risks of birth defects also increase if a mother is overweight, as does the likelihood the child will grow up to be obese, researchers said.

The findings spotlight the need for women intending to get pregnant to start an exercise routine early on. Researchers point out that moderate exercise during pregnancy is still considered healthy. They recommend 30 minutes per day for overweight and obese moms-to-be, in addition to stretching exercises and nutrition counseling.

"Pregnancy is not a state of confinement and indulgence,” said Dr. Raul Artal, head of obstetrics, gynecology and women's health at Saint Louis University School of Medicine.