The risks and benefits of exercise during pregnancy.

There are benefits as well as risks associated with physical activity in all individuals, but there are some special medical considerations for the pregnant woman. The purpose of this article is to review the possible risks and benefits of exercise during pregnancy as presented in the literature, and to provide appropriate recommendations. There are some potential risks to the fetus resulting from maternal exercise including hypoxia, hyperthermia, and abnormal heart rate changes. The benefits, however, appear to outweigh the risks when they are minimized by prescribing appropriate exercises and using recommended precautions. Because human studies on exercise during pregnancy are currently limited, exercise prescriptions should be conservative. Swimming, biking, and aerobic walking are not associated with reported problems. Moderate aerobic exercise is safe provided the pregnancy is known to be normal. Contraindications to aerobic exercise during pregnancy include conditions that limit cardiorespiratory reserves. If a woman has been participating in an exercise program before gestation, she may be encouraged to continue the program at a moderate level if her pregnancy is normal.