This study evaluated the effects of a physical conditioning program on pregnancy outcomes and the subjective pregnancy experience. Pregnancy outcomes included length of labor, mode of delivery, length of hospitalization, and gestational age, birth weight, and Apgar scores of newborn infants. Subjective data included level of tension, general physical comfort, and self-image. The 845 subjects in the study were divided into a control group (n = 393) and into groups of low, medium, and high levels of exercise (n = 82, 309, and 61, respectively). Exercise sessions consisted of treadmill or bicycle warm-up, individually prescribed exercises on weight-lifting equipment for arms, legs, abdomen, and back, and 1- to 2-mile workout on bicycle ergometer. Pregnancy outcomes were more favorable in the exercise groups, particularly the high-exercise group. Significant data included length of hospitalization, incidence of cesarean section, and Apgar scores. All patients reported positive subjective responses to the conditioning program.