The effect of physical exercise on postpartum fitness, hormone and lipid levels: a randomized controlled trial in primiparous, lactating women.

Purpose: To evaluate the effect of an exercise training program combining low-impact dance aerobic, resistance and stretching exercise on physical fitness, hormone and lipid levels of postpartum, primiparous, lactating women.

Methods: Thirty seven primiparous, lactating women were randomly assigned at 4-6 weeks postpartum to either follow an exercise training program of 50-60 min aerobic, strengthening and stretching exercise, 3 days a week, for 12 weeks (interventional group; n = 20) or no training program at all (control group; n = 17). The following parameters were measured at baseline and 12 weeks later: (1) for evaluation of physical fitness: VO2max, muscular endurance, joint mobility and body fat; (2) for evaluation of the lipidemic profile: triglyceride, total cholesterol, HDL and LDL levels, and (3) levels of hormones associated with lactation: prolactin, estradiol, cortisol, TSH, fT3 and fT4.