For years it was believed that  pregnant  women should spend nine months prone on the couch, resting comfortably. Doctors feared that the jarring motion of aerobics or running could damage the fetus, and prescribed rest for even the most intense of professional athletes. Fortunately, the tide has turned. Pioneers such as James Clapp., M.D. and Elizabeth Noble have proven through their work that exercising  actually makes for an easier pregnancy and delivery. In fact, Dr. Clapp found through a study of 500 pregnant women that those who exercised delivered a healthier baby with a stronger fetal heart rate. Even more compelling is the fact that of the women who exercised, time spent in labor was shortened by about a third, with 65% of the women delivering in four hours or less. Exercising also seems to ease some common ailments, such as lower back pain and fatigue.

Even if you never exercised regularly before, a program can be undertaken safely. If you have been following a regular exercise regime, there’s no reason you shouldn’t be able to continue on the same level for the first trimester. Particularly if you suffer from morning sickness, be aware of your limits.

Monitor your heart rate and breathing. As a general rule, your heart rate should not exceed 140 beats/minute. The fetal heart rate is tied to your own; if your heart is racing, your baby’s is too. A heart rate monitor, at around a hundred dollars, is a worthwhile investment. Most feature an alarm that sounds if you exceed the safe target range. Adjust your exercise levels accordingly.

Avoid exercising at extreme altitude or in hot, humid environments. Your body temperature affects the baby, and it is critical that neither of you becomes overheated. Drink plenty of water.

As the pregnancy progresses, reduce the intensity level. Early in pregnancy, a hormone called relaxin fills your system. It is common for women to strain muscles and ligaments during pregnancy as a result of this new flexibility. In the last trimester, avoid ballistic movements, such as jumping or running. The exercise community is divided on this one. There are plenty of exercises that can be done without bouncing motions. Do 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. Kegels involve contracting and releasing the PF muscles, similarly to stopping the flow of urination.

In the first trimester, almost any form of exercise (outside of contact sports and skiing) can be undertaken safely. During the later trimesters, running and cycling tend to become uncomfortable. Most of the women that I trained switched from these sports to swimming, hiking, water aerobics, and cross-country skiing. Every woman that I worked with lifted weights right up to the end. In my experience, the postpartum recovery period was dramatically easier for the women who exercised. Just five weeks after delivering a beautiful, healthy baby boy, she had already lost fifteen pounds and felt great!

Pregnancy causes so many physical and lifestyle adaptations, it can be overwhelming.