Aerobic exercises in pregnancy

Each workout or exercise session should consist of three parts: a warm-up period, the aerobic workout, and a cool-down period.

The Warm-Up

Don't neglect this. No aerobic workout should be started on a "cold" body. Warm-up moves signal your body that more vigorous activity is coming and prevent injury by releasing muscle tension and making the body more flexible.

Spend a minimum of five minutes (ten minutes is much better) stretching and limbering up. Stretch just to the point of mild tension (not pain), and then hold the stretch for a slow count of ten. Release and repeat, three times in all. Whichever warm-up stretch you choose, do not bounce! It only makes your muscles tighter.

Concentrate stretches mainly on the lower body (legs, ankles, hips, knees), but don't completely neglect the upper body (arms, shoulders, neck). If you are lap swimming, walking, biking, or engaging in some other independent activity, spend another five minutes moving slowly, and then gradually move faster and faster toward your target zone. In other words, don't stretch and then try to burst into your pulse range.

The Stretches

Hold each stretch for 10 seconds.

Calf Stretch:

1. Face a wall for support. Stand a little distance from the wall and rest your forearms on the wall. Place your forehead on the backs of your hands, and keep your back flat.

2. Bend one knee and bring it toward the wall. Keep your back leg straight and your foot flat, your heel pressed into the floor. Create an easy feeling of stretch in your calf muscle.

3. Hold an easy stretch for 10 seconds, then increase the stretch feeling just slightly for another 10 seconds.

4. Repeat with the other leg.

Soleus (Deep Calf) and Achilles Tendon Stretch:

1. Start in the same position as for the calf stretch.

2. Lower hips downward as you slightly bend your knees. Be sure to keep your back flat. Point your back foot straight ahead during the stretch. Keep your heel pressed down to the floor.

3. Repeat with the other leg.

This stretch is good for developing ankle flexibility. The Achilles tendon area needs only a slight feeling of stretch.

Back, Calf, and Hamstring Stretch:

1. Sit with one leg bent and the other leg stretched out forward. Keep the knee of the straight leg relaxed.

2. Find an easy stretch. Lean forward from the hips to increase the stretch.

The Aerobic Workout

Spend a minimum of 12 minutes with your pulse in your target zone. Be aware that you may need to spend a little longer than 12 minutes in your activity to meet the 12-minute requirement. For instance, you may have to bike 20 minutes to actually keep your pulse within your target zone for 12 continuous minutes, or walk briskly for 15 to 20 minutes to satisfy the 12-minute minimum. (The accompanying chart shows a recommended walking program.)

During pregnancy, the American College of Obstetricians and Gynecologists recommends at least 30 minutes of moderate physical activity.

This amount of time is sufficient, when repeated three to five times a week, to develop or maintain aerobic fitness. Until you increase your body awareness and know the internal feelings that mean you are in the correct pulse zone, depend on your watch, frequent pulse checks, and the talk test.

The Cool-Down

Once you stimulate your circulation and complete your 12-minute workout, slow down your activity gradually, over a 5-minute period. Before you actually sit down (or begin strengthening exercises), your pulse should be below 110 beats per minute or the low end of your target zone, whichever is lower. Then stretch again for 5 minutes (10 minutes is even better), and you're done!