Exercise During Pregnancy - 13 Rules

Exercise has great benefits, but during pregnancy you need to approach it with extra caution. Whether you're a regular exerciser looking to continue your regime during pregnancy, or a former couch potato looking to get moving, follow these 13 rules to keep yourself and your baby safe.

1. Check with your healthcare provider first

If you exercised regularly before getting pregnant and your pregnancy is problem-free, you can most likely continue working out as before — with modifications as noted below. There are exceptions to this general rule, so talk to your doctor or midwife about your fitness routine to make sure your activities don't put you or your baby at risk.

If you're starting from scratch as a non-exerciser, see our exercise guide for beginners, and talk to your healthcare provider.

2. Take in extra calories

Get the 300 to 500 additional calories a day you need during pregnancy, especially if you're exercising. Make sure to eat well to help nourish and strengthen your body.

3. Steer clear of dangerous sports

Avoid contact sports, as well as activities that might throw you off-balance, such as horseback riding or biking. Even if you're normally graceful, keep in mind that the increased levels of the hormone relaxin during pregnancy, which relax pelvic joints in preparation for childbirth, loosen all ligaments and joints, making you more susceptible to sprains and injury from falls.

4. Wear the right clothes

Wear loose-fitting, breathable clothing. Dress in layers so it's easy to peel off a layer or two after you've warmed up (or if you simply feel too hot). Make sure your maternity bra offers enough support, and choose athletic shoes that fit your feet properly and offer good support. If your shoe size has changed because of mild swelling, stash away your pre-pregnancy sneakers and buy a new pair.

5. Warm up

Warm-ups prepare your muscles and joints for exercise and build your heart rate up slowly. If you skip the warm-up and jump into strenuous activity before your body is ready, you could strain your muscles and ligaments and experience increased post-workout aches and pains.

6. Drink plenty of water

Drink water before, during, and after exercising. Otherwise, you can become dehydrated, which can cause contractions and raise your body temperature, sometimes to levels that are dangerous for you and your baby. James M. Pivarnik, Ph.D., of Michigan State University, says that while there's no official recommendation for how much water pregnant women should drink while exercising, a good guideline is to drink one cup (8 ounces) before you exercise, one cup for every 20 minutes of exercise, and one cup after you finish your workout. In hot and/or humid weather, you'll need more.

7. Don't lie flat on your back

Avoid lying flat on your back after the first trimester. This position puts pressure on a major vein called the vena cava, which will diminish blood flow to your brain and uterus, and can make you dizzy, short of breath, or nauseated. Some women are comfortable in this position well into their pregnancies, but this isn't necessarily a good gauge of whether blood flow to the uterus is affected. Placing a pillow under your right hip or buttock will allow you to be almost supine without compressing the vena cava.

8. Keep moving

Standing motionless for prolonged periods — as when you're lifting weights or doing yoga poses — can decrease blood flow to the uterus and cause blood to pool in your legs, making you dizzy. Keep moving by switching positions or walking in place.

9. Don't overdo it

Don't exercise to exhaustion. A good rule of thumb: Slow down if you can't comfortably carry on a conversation. In general, the best guideline is to listen to your body. When something hurts, that means something's wrong, so stop. You should feel like you're working your body, not punishing it.

10. Don't get overheated

Avoid letting yourself get too hot, especially during the first trimester when your baby's major organs are developing. Although there's no proof of a danger to humans, some animal studies suggest that overheating can cause birth defects.

Increased blood flow and a higher metabolic rate mean you'll feel warmer than usual when you're pregnant, and doubly so when you exercise. And since feeling warm is common in pregnancy, you may get overheated much faster than you normally would, even before your belly is big.

Signs of being overheated are largely individual, but pay attention if you're sweating a lot, feel uncomfortably warm, or feel dizzy or short of breath. On hot and/or humid days, skip your workout or exercise indoors in a well-ventilated, air-conditioned room. Wear loose, non-binding clothing and drink plenty of water.

To cool off quickly, stop exercising, take off layers, and change your environment: seek out air conditioning or step into a cool shower. Hydrating is key, too, so drink lots of water.

11. Get up from the floor slowly

As your belly grows, your center of gravity shifts. That's why it's important to take great care when you change positions. Getting up too quickly can make you dizzy, and may cause you to lose your footing and fall.

12. Cool down

At the end of your workout, take a few minutes to walk in place and then stretch. Heart rate increases during pregnancy and it may take as long as 15 minutes for your heart to return to its resting rate following a workout.

13. Make it a habit

Make a commitment to work regular exercise into your schedule. Keeping up a routine is easier on your body than periods of inertia interrupted by spurts of activity. According to the American College of Obstetricians and Gynecologists, you can safely engage in 30 minutes or more of moderate exercise on most, if not all, days of the week as long as you have your healthcare provider's go-ahead.

Reviewed by Vicki Lee Edge, M.D., August 2006