The labor and delivery outcomes were compared for 50 low-risk primiparas who voluntarily participated in a structured, nonendurance antepartum exercise program and a similar, nonexercising control group. No adverse effects on fetal well-being were noted in the exercising group. However, those who exercised had significantly shorter first and second stages of labor (mean length, 7.55 and 1.33 hours, respectively; P less than .001) as compared to those who did not exercise (mean length, 14.46 and 2.47 hours, respectively; P less than .001). The exercising primiparas were also less likely to require oxytocin augmentation of labor and more likely to have spontaneous vaginal deliveries. The data suggest that there might be beneficial effects from nonendurance antepartum exercise regimens for women with normal pregnancies. Hence, the data have implications for the counsel given pregnant women about antenatal exercise and for future research on exercise during pregnancy.