Exercising during Pregnancy

The key word in pregnancy is change. During this 40-week period, a woman's body goes through many changes including stretching of muscles, softening of ligaments (tissues connecting two bones), and loosening of joints. You can better adapt to these physiologic changes through regular exercise. By using common sense and understanding your individual needs, you can plan and participate in a safe and effective exercise program throughout your pregnancy and your life.
Whether you're a seasoned athlete or a self-proclaimed couch potato, exercise can make your pregnancy much more enjoyable. If you exercised regularly before pregnancy, the American College of Obstetricians and Gynecologists recommends that you take precautions and receive ongoing guidance from your doctor. Focus on maintaining your previous level of fitness rather than on advancing your fitness level. If you have been inactive and want to start an exercise program, talk with your doctor. He or she can help you design a program best suited to your needs and abilities. You should wait to start this program until the second trimester (weeks 13 to 28) of pregnancy. Starting the program before this time potentially can lead to birth defects and other complications due to overheating.
A safe type of exercise program for most pregnant women includes cardiovascular fitness, muscle strengthening, stretching, and relaxation. These exercises should be done regularly - at least three times each week. The workout intensity should be light to moderate, and your heart rate should not exceed 140 beats per minute.

Warming up
A warm-up exercise should precede any physical activity. It should consist of slow walking or stationary bicycling for five to eight minutes followed by a gentle, sustained stretch to the point of mild tension. Do not stretch to the point of pain and do not stretch as far as you can go. Remember, your connective tissues, such as muscles and ligaments, are lax.

Cardiovascular exercise
The ideal type of cardiovascular exercise during pregnancy is nonweight-bearing activities, such as stationary bicycling, swimming, and aquatic exercising. Exercising in the water provides buoyancy, increases joint cushioning, and enhances heat dissipation. While in the water, you may find that the strain on your back decreases - a welcome relief, especially late in pregnancy. However, when exercising in a heated pool, limit the amount of time you spend in that environment. The warm water may cause your internal temperature to rise, which can be unsafe for your baby. If you are uncomfortably warm, you need to get out of the pool.
Walking is another good activity for the beginning exerciser and for the long-time athlete who wants to maintain a good level of fitness. If you are an avid exerciser, take common sense precautions and consult your doctor if you plan to continue more strenuous activities, such as jogging or low-impact aerobics.

Strengthening
In addition to aerobic activity, you need to strengthen your muscles. The extra weight carried during pregnancy can cause back pain. To prevent this pain, strengthen your abdominal and back muscles by doing the pelvic tilt (Figs. 1A and 1B).

If you lift weights, make sure you only lift a weight equal to or less than the weight you lifted before pregnancy. You are lifting to maintain previous muscle tone and not lifting to build muscle mass. Remember to exhale on the contraction of the muscle. Holding your breath then forcibly exhaling (the Valsalva maneuver) while lifting these weights decreases blood flow to your heart. During the third trimester (week 28 to birth), you can use hand-held weights if you are careful; your body has had many physiologic changes and is not as balanced as it was before pregnancy. If you experience chronic fatigue or exhaustion from exercise, discontinue exercising and consult your physician.
Include Kegel exercises to strengthen the muscles used in labor. To do these exercises, contract and release the perineum (the pelvic floor and associated structures). This movement is the same one used to stop the urine stream.

Stretching and relaxing
Take the time to stretch and relax during pregnancy (Figs. 2A and 2B). Always avoid jerky or bouncy motions when you stretch. Control your breathing by slowing inhaling and exhaling. Remember to stretch your entire body, especially the heel cords to prevent leg cramping (Fig. 2C). After the fourth month, avoid lying flat on your back or on your right side when exercising or relaxing. This position restricts the blood flow to the uterus. It is best to lie on your left side.

Special considerations
Exercising mothers-to-be need to avoid overexerting themselves. Limit your exercise outings to 15 minutes. Wear supportive shoes and watch the surface carefully to avoid losing your balance and injuring yourself. On hot, humid days, find a cool place to exercise, such as a mall or a health club. Drink plenty of water before, during, and after exercising to avoid dehydration. Drink at least eight glasses of water each day and, on workout days, drink extra glasses to replenish the fluid lost. Do not participate in activities, such as ball sports, that put you at risk for a blow to your abdominal area.
Your body needs more energy from food during pregnancy. A pregnant woman normally needs to consume about 300 calories more than she did before pregnancy. When you exercise, you need to consume enough calories to offset the calories you burn.
Exercise can help you maintain a positive self-image and physical well being during this time. It can help you feel in control of your body and can make pregnancy a little easier. Continue exercising throughout pregnancy, the postpartum period, and the rest of your life.

Mary Ann Collins
Columbus, Georgia