Not only is it safe (once you get the "go ahead" from your doctor) to exercise during pregnancy, it's a good idea. A solid 30 minutes of exercise every day can help reduce backaches and constipation -- two common pregnancy complaints. It may also help you sleep better and boost your posture and mood, two things that tend to wane as pregnancy progresses.
Working out during pregnancy promotes muscle tone and strength, helps you cope with labor pain and allows you to bounce back after pregnancy [source: American Congress of Obstetricians and Gynecologists]. Exercise, especially the kind that includes fresh air, may even help ease morning sickness [source: Cram].
Some exercises, such as walking, yoga, swimming and low-impact aerobics, are ideal even for beginners. Activities such as running may be safe for baby and mom, but only if you were already doing them on a regular basis before becoming pregnant, and you still might need to modify the workout [source: Butler]. The key to exercising safely, regardless of your pregnancy fitness level, is to know the signs of overexertion. Read on to discover what to watch for.