In general, working out is great for a pregnant woman if there are no specific conditions or complications that make exercising off-limits to her. This means if she was previously active, she can continue with low-impact aerobics and appropriate strength training exercises—that is, as long as she has her doctor’s approval and makes proper modifications if needed.

When women exercise during their pregnancy they can reduce backaches and fatigue, relieve stress, and build up the stamina they’ll need during labor and delivery. According to health experts, exercise may also prevent them from developing gestational diabetes (diabetes that occurs during pregnancy).

Additionally, even if you’ve never previously exercised, docs generally will OK moms-to-be beginning an exercise program. Just make sure you discuss it with your doctor beforehand. In general, docs will probably rule out very strenuous activity. But walking and swimming usually get a nod from your doctor.

Finally, the American College of Obstetrics and Gynecology suggests moms-to-be who are free of any medical issues engage in 30 minutes or more of moderate exercise daily.