There has been a progressive evolution in the concept of exercise for prepartum women. Per contra, screening guidelines have not changed. All women should have a thorough clinical evaluation by the health care team before an exercise program is recommended. This is true for previously sedentary women or women who have been active before their pregnancy. The consensus today is that given no medical contraindications to exercise during pregnancy women with uncomplicated pregnancies should participate in moderate exercise, such as brisk walking, 30 min a day or more. The use of heart rate to guide intensity is not valid for prepartum women because of the large variability of heart rate during pregnancy. Rather, metabolic equivalents (METS), the Rating of Perceived Exertion Scale (RPE) or methods such as the talk test should be used to monitor exercise intensity. The recommendation is 3-5 METS, an RPE of 12-14 (somewhat hard) on the 6-20 scale, or women should be able to maintain a conversation while exercising. Strength-conditioning activites are also advocated in uncomplicated pregnancies. However, there is less evidence on strength conditioning and weight training in pregnancy. The research on yoga and Plates on gravid women is too limited to make a position stand on these activities. Regardless of the type of activity, all goals should be reasonable. Furthermore, pregnancy it is not a time to reach peak fitness levels or train for an athletic competition. Elite athletes who train during pregnancy require supervision by an obstetric care provider with knowledge of the impact of strenuous exercise on fetal outcomes.