HEATHER, athlete and personal trainer: First and foremost congratulations on your pregnancy! Research has shown that women with low-risk pregnancies can exercise safely throughout their pregnancies. In fact, moderate physical activity is considered beneficial for most pregnant women and their babies. Regular, moderate exercise can help prevent constipation and varicose veins, relieve backache, prepare your body for childbirth and maintain overall physical fitness. Despite the benefits of physical activity, it is important to check with your health-care provider before you begin. In addition, there are a few important things that pregnant women should know:

Begin your exercise program slowly, especially if you have never exercised. The most important thing is to listen to your body. If it feels like you are pushing yourself too much, then you probably are. This is not the time to set the new world record for running the mile! As the pregnancy progresses, reduce the intensity level of the exercise. In the last trimester, it may be best to avoid ballistic movements such as jumping or running.

Monitor your heart rate and breathing. Remember the fetal heart rate is tied to your own, so if your heart is racing, your baby's is too. Get a heart rate monitor that features an alarm that sounds when you are in your target heart rate zone. If you feel breathless, which is common during the first trimester, slow down or take a break. Don't forget, the first three months are an adjustment period when your blood volume may initially be too low to accommodate both you and a growing fetus, which can result in breathlessness and faintness.

Avoid exercising at extreme altitudes or in hot, humid environments. Your body temperature affects the baby, and it is critical that neither of you becomes overheated. Don't forget to drink plenty of water.

Be careful not to overstretch. Early in pregnancy, a hormone called relaxin fills your system. This hormone induces hyper-flexibility in the joints and musculature, which allows for the expansion of the uterus and the repositioning of the pelvic floor. It is common for women to strain muscles and ligaments during pregnancy as a result of this new flexibility.

Do your Kegel exercises religiously. The pelvic floor supports the bladder, uterus, and intestines. The added weight of the uterus during pregnancy can stretch out that floor, causing either the intestines or bladder to drop down, which can lead to incontinence. Kegels involve contracting and releasing the pelvic floor muscles, similarly to stopping the flow of urination. Tighten and relax the muscle quickly several times a day.

Finally, choose an exercise that you enjoy. In the first trimester, almost any form of exercise (with the exception of contact sports and skiing) can be undertaken safely. During the later trimesters, running and cycling may become uncomfortable, but again listen to your body. As an advocate of strength training, my pregnant female clients continued with their training routines for the duration of their pregnancies. In my experience, the postpartum recovery period was dramatically easier for the women who exercised compared to those who chose not to participate. Again, check with your physician before undertaking any exercise program.

Posted April 15, 2003 02:29 AM