Three months of aerobic exercise training reduces depressive symptoms in pregnant women. A randomized trial assigned 80 nulliparous pregnant women to either a 3-month supervised aerobic exercise program or their usual activities. The exercise program consisted of walking, aerobic exercise, stretching, and relaxation 3 times per week. After the intervention, women in the exercise group reported fewer depressive symptoms on a depression questionnaire compared to the control group. Supervised aerobic exercise during pregnancy may help reduce symptoms of depression.