Feel better: At a time when you wonder if this strange body can possibly be yours, exercise can increase your sense of control and boost your energy level. Not only does it make you feel better by releasing endorphins (naturally occurring chemicals in your brain), appropriate exercise can: Relieve backaches and improve your posture by strengthening and toning muscles in your back, butt, and thighs reduce constipation by accelerating movement in your intestine. Prevent wear and tear on your joints (which become loosened during pregnancy due to normal hormonal changes) by activating the lubricating fluid in your joints. Help your sleep by relieving the stress and anxiety that might make you restless at night.

Look better! Exercise increases the blood flow to your skin, giving you a healthy glow. Prepare you and your body for birthing. Strong muscles and a fit heart can greatly ease labor and delivery. Gaining control over your breathing can help you manage pain. And in the event of a lengthy labor, increased endurance can be a real help.

Regain your pre-pregnancy body more quickly. You'll gain less fat weight during your pregnancy if you continue to exercise (assuming you exercised before becoming pregnant). But don't expect or try to lose weight by exercising while you're pregnant. For most women, the goal is to maintain their fitness level throughout pregnancy.