Aerobic Exercise During Pregnancy

The goal of an aerobic exercise program is to improve heart and lung performance. Aerobic exercise programs for expectant mothers should include at least five minutes of “warm-up” including slow, smooth movements and stretching; a period of sustained, vigorous exercise lasting approximately fifteen minutes; and a “cool-down” consisting of mild activity while your heart rate returns to normal. Exercise for strength and flexibility are sometimes added.

The American College of Obstetricians and Gynecologists (ACOG) recommends that you take your pulse at times of peak activity and reduce your exercise intensity if your pulse rate exceeds 140 beats per minute. At a pulse rate of 120 to 140, you can improve your fitness without risking overexertion, no matter how accustomed you are to regular exercise. If you exercise regularly you will need more intense activity to raise your heart rate to 140; if you do not exercise regularly, mild exertion will elevate your heart rate to this level. In addition to taking your pulse, you will want to be sure that your activity passes the ‘talk test’; it is too vigorous for you if you are gasping and are unable to continue a conversation. Slow your activity to a level that allows you to continue talking. Guidelines for aerobic exercise during pregnancy are based on your age, health and fitness level.

If you choose an aerobic program, start slowly and gently. Avoid exhausting exercise that may adversely affect your baby. Stop exercising if you experience pain, headache, nausea, severe breathlessness, dizziness, vaginal bleeding, or loss of muscle control. You can let your body be your guide if you listen to it carefully.

What kind of aerobic exercise is best for pregnant women? Generally speaking, low impact exercise (exercise that does not involve jumping, bouncing or leaving the ground) is preferable because it is easier on your joints, which become more susceptible to injury or strain as pregnancy advances. Brisk walking, cross-country skiing, cycling, swimming and low-impact aerobic classes (in or out of water) are examples of low-impact activities. Swimming and low-impact aerobic classes tend to provide more total body involvement than the others listed above.

Swimming and water exercise offer still other advantages that make them superior to land exercise for pregnant women. They produce the lowest impact possible because of the buoyancy provided by the water. Vigorous land exercises sometimes cause a risk in your temperature and a drop in the baby’s heart rate, which means that the baby’s oxygen supply has dropped. Immersion in water prevents these potential problems. It has the added advantage of reducing swelling (edema) by moving tissue fluid back into your circulation and allowing you to excrete it through urination. In fact, this benefit has been found to last approximately forty-eight hours after one hour in water.