Although you may not feel like running a marathon, most women benefit greatly from exercising throughout their pregnancies. But during that time, you'll need to discuss your exercise plans with your doctor or other health care provider early on and make a few adjustments to your normal exercise routine. The level of exercise recommended will depend, in part, on your level of pre-pregnancy fitness.

Benefits of Exercising During Pregnancy

No doubt about it, exercise is a big plus for both you and your baby (if complications don't limit your ability to exercise throughout your pregnancy). It can help you:

• 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 you sleep better 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 birth. 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.

While the jury's still out on the additional benefits of exercise during pregnancy, some studies have shown that exercise may even lower a woman's risk of complications, like preeclampsia and gestational diabetes.

What's Safe During Pregnancy?

It depends on when you start and whether your pregnancy is complicated. If you exercised regularly before becoming pregnant, continue your program, with modifications as you need them.

If you weren't fit before you became pregnant, don't give up! Begin slowly and build gradually as you become stronger. The U.S. Department of Health and Human Services recommends at least 150 minutes (that's 2½ hours) of moderate-intensity aerobic activity each week for healthy women who are not already highly active or doing vigorous-intensity activity.

If you're healthy, the risks of moderate-intensity activity during pregnancy are very low, and do not increase risk of low birth weight, pre-term delivery, or early pregnancy loss.

Before you continue your old exercise routine or begin a new one, you should talk to your doctor about exercising while you're pregnant. Discuss any concerns you may have and know that you might need to limit your exercise if you have:

• pregnancy-induced high blood pressure
• early contractions
• vaginal bleeding
• premature rupture of your membranes, also known as your water (the fluid in the amniotic sac around the fetus) breaking early

Exercises to Try

That depends on what interests you and what your doctor advises. Many women enjoy dancing, swimming, water aerobics, yoga, Pilates, biking, or walking. Swimming is especially appealing, as it gives you welcome buoyancy (floatability or the feeling of weightlessness). Try for a combination of cardio (aerobic), strength, and flexibility exercises, and avoid bouncing.

Many experts recommend walking. It's easy to vary the pace, add hills, and add distance. If you're just starting, begin with a moderately brisk pace for a mile, 3 days a week. Add a couple of minutes every week, pick up the pace a bit, and eventually add hills to your route. Whether you're a pro or a novice, go slowly for the first 5 minutes to warm up and use the last 5 minutes to cool down.

If you were a runner before you were pregnant, you might be able to continue running during your pregnancy, although you may have to modify your routine.

Whatever type of exercise you and your doctor decide on, the key is to listen to your body's warnings. Many women, for example, become dizzy early in their pregnancy, and as the baby grows, their center of gravity changes. So it may be easy for you to lose your balance, especially in the last trimester.

Your energy level might vary greatly from day to day. And as your baby grows and pushes up on your lungs, you'll notice a decreased ability to breathe in more air (and the oxygen it contains) when you exercise. If your body says, "Stop!" — stop!

Your body is signaling that it's had enough if you feel:

• fatigue
• dizziness
• heart palpitations (your heart pounding in your chest)
• shortness of breath
• pain in your back or pelvis

And if you can't talk while you're exercising, you're doing it too strenuously.

It also isn't good for your baby if you become overheated because temperatures greater than 102.6°F (39°C) could cause problems with the developing fetus — especially in the first trimester — which can potentially lead to birth defects. So don't overdo exercise on hot days.

During hot weather, avoid exercising outside during the hottest part of the day (from about 10 a.m. to 3 p.m.) or try to exercise in an air-conditioned place. Also remember that swimming makes it more difficult for you to notice your body heating up because the water makes you feel cooler.

Exercises to Avoid

Most doctors recommend that pregnant women avoid exercises after the first trimester that require them to lie flat on their backs.

Unless your doctor tells you otherwise, it's also wise to avoid any activities that include:

• bouncing
• jarring (anything that would cause a lot of up and down movement)
• leaping
• a sudden change of direction
• a risk of abdominal injury

Typical limitations include contact sports, downhill skiing, scuba diving, and horseback riding because of the risk of injury they pose.

Although some doctors say step aerobics workouts are acceptable if you can lower the height of your step as your pregnancy progresses, others caution that a changing center of gravity makes falls much more likely. If you do choose to do aerobics, just make sure to avoid becoming extremely winded or exercising to the point of exhaustion.

And check with your doctor if you experience any of these warning signs during any type of exercise:

• vaginal bleeding
• unusual pain
• dizziness or lightheadedness
• unusual shortness of breath
• racing heartbeat or chest pain
• fluid leaking from your vagina
• uterine contractions

Kegel Exercises

Although the effects of Kegel exercises can't be seen from the outside, some women use them to reduce incontinence (the leakage of urine) caused by the weight of the baby on their bladder. Kegels help to strengthen the "pelvic floor muscles" (the muscles that aid in controlling urination).

Kegels are easy, and you can do them any time you have a few seconds — sitting in your car, at your desk, or standing in line at the store. No one will even know you're doing them!

To find the correct muscles, pretend you're trying to stop urinating. Squeeze those muscles for a few seconds, then relax. You're using the correct muscles if you feel a pull. Or place a finger inside your vagina and feel it tighten when you squeeze. Your doctor can also help you identify the correct muscles.

A few things to keep in mind when you're doing Kegel exercises:

• Don't tighten other muscles (stomach or legs, for example) at the same time. You want to focus on the muscles you're exercising.
• Don't hold your breath while you do them because it's important that your body and muscles continue to receive oxygen while you do any type of exercise.
• Don't regularly do Kegels by stopping and starting your flow of urine while you're actually going to the bathroom, as this can lead to incomplete emptying of your bladder, which increases the risk of urinary tract infections.

Getting Started

Always talk to your doctor before beginning any exercise program. Once you're ready to get going:

• Start gradually. Even 5 minutes a day is a good start if you've been inactive. Add 5 minutes each week until you reach 30 minutes.
• Dress comfortably in loose-fitting clothes and wear a supportive bra to protect your breasts.
• Drink plenty of water to avoid overheating and dehydration.
• Skip your exercises if you're sick.
• Opt for a walk in an air-conditioned mall on hot, humid days.
• Above all, listen to your body.

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: November 2011