It is now recommended that women utilize the rate of perceived exertion (RPE) scale instead of a target heart rate. It is recommended that during pregnancy a woman should maintain a level of exercise she considers to be fairly light to somewhat hard (RPE of 11-13 on the Borg 6-20 scale). For women who do not have any additional risk factors for adverse maternal or perinatal outcome, the following recommendations may be made. During pregnancy, woman can continue to exercise and derive health benefits even from mild-to-moderate exercise routines. Regular exercise (at least three times per week) is preferable to intermittent activity. Prolonged periods of motionless standing should also be avoided. If you have been sedentary prior to conception, it is important to begin any exercise program gradually and progress slowly.

Women should be aware of the decreased oxygen available for aerobic exercise during pregnancy. They should be encouraged to modify the intensity of their exercise according to maternal symptoms. Pregnant women should stop exercising when fatigued and not exercise to exhaustion. Weight-bearing exercises may, under some circumstances, be continued at intensities similar to those prior to and throughout the pregnancy. Morphologic changes in pregnancy should serve as a relative contraindication to types of exercise in which loss of balance could be detrimental to maternal or fetal well-being, especially in the third trimester.

Further, any type of exercise involving the potential for even mild abdominal trauma should be avoided. Pregnancy requires an additional 300 kcals per day in order to maintain metabolic homeostasis. Thus, women who exercise during pregnancy should be particularly careful to ensure an adequate diet. Pregnant women who exercise in the first trimester should augment heat dissipation by ensuring adequate hydration, appropriate clothing, and optimal environmental surroundings during exercise. Many of the physiologic and morphologic changes of pregnancy persist for four to six weeks postpartum. Thus, pre-pregnancy exercise routines should be resumed gradually based on a woman's physical capability.