Times have changed. No longer is pregnancy considered a diseased state during which the woman must lie down for nine months. Pregnant women can stay involved in their careers and their leisure activities. With few restrictions, the average pregnant woman should continue her daily routine as much as possible including an exercise program. Pregnancy is a time to maintain but not to strenuously increase your physical fitness level. It is a time to listen carefully to your body and modify your exercise program as the body changes.

Guidelines for exercise
The American College of Obstetricians and Gynecologists has provided a guide to safe exercise limits for the pregnant woman. In summary, these guidelines state the following:

• Do not do supine (flat on the back) exercises after the beginning of the fourth month of the pregnancy. The major vein that returns the blood from the lower limbs to the heart lies along the mother's right side, under the baby and uterus. When lying on her back, the mother shifts the weight of the baby onto the vein and decreases the blood flow like a pinched garden hose. The best position for an expectant mother is to lie on her left side so that the weight of the baby shifts away from this blood vessel.
• Make twisting motions and movements that require good balance carefully. Because the expectant mother's center of gravity changes as the baby grows, it throws her sense of balance off and may cause her to fall more easily. Being able to balance well is important in aerobics classes, which often include quick changes of body position and direction.
• Your heart rate should stay lower than 140 beats per minute (bpm) even during exercise. A good way to find your pulse is to place the fingertips of your right hand on the thumb side of your left wrist. Another way is to touch the corner of your eye and run your fingertips down to locate the pulse in your neck just below the jawline. You can count the beats per minute using a watch with a second hand.
• Your core, or internal, temperature should not rise above 102° F so monitor where and how intensely you exercise. A high core temperature can cause some birth defects. Exercise during early morning or late evening rather than the middle of a hot day. Also, exercise indoors if the outside temperature is hot.
• Drink plenty of fluids, especially water, so you will not become dehydrated. All people should drink one 8 ounce glass of water for every pound of scale weight that they lose during exercise.

The pregnant mother can participate in her existing program or routine or in a prenatal fitness class. Prenatal fitness classes should include flexibility or stretching exercises for the back and legs. Many pregnant women get muscle cramps in their legs, particularly their calves. The best way to prevent this is to stretch the heel cords daily, especially at night before going to bed. To do this stretch, first place your hands on a wall. Next, place your right foot a comfortable distance from the wall and place the left foot about 6 inches from the wall. Finally, lean into the wall. Make sure your toes are pointing directly toward the wall. You should feel a gentle stretch or pull through the right calf. if the stretch is too much, pull the right foot closer to the wall. If there is not enough of a stretch, move the right foot away from the wall. To stretch the left calf, move the left foot away from the wall and the right foot to about 6 inches from the wall. Repeat the exercise.

Training for motherhood
Muscle strengthening with emphasis on the back and arms should also be included in your exercise program. The growing baby and enlarging breasts add extra stress to your back. Also, after the baby is born, you will be carrying him or her in your arms, and the baby will be growing heavier very quickly. include a cardiovascular or aerobic workout. This entails some sort of continuous activity that elevates the heart rate up to, but no higher than 140 bpm. The best activities for many women are walking and swimming. Both of these activities place only mild stress on the joints.

Remember they do not call it labor for nothing. You would not run a marathon without training. The more fit you are, the better equipped you will be to withstand labor. Prenatal fitness will not shorten labor. However, if you are physically fit, you should be able to tolerate labor better and to return more quickly to your pre-pregnant state. As with any exercise program, you need to discuss your plans for exercise with your physician. Your obstetrician will provide the best individual guidance.

Laura R. Stokes, M.S.
Columbus, Georgia