The postpartum period represents a high-risk period for body weight retention and obesity. Several studies have investigated the role of aerobic exercise on postpartum weight retention and other body composition outcomes; however, there has been little attention given to resistance training in postpartum women. Thus, the purpose of this four-month randomized study was to determine the effectiveness of resistance training on strength, body composition, return to pre-pregnancy weight, and bone mineral density (BMD) in postpartum women. Sixty postpartum women were randomly assigned to either a resistance training group or a comparison group. The resistance training group participated in a progressive resistance training program twice weekly for four months. The comparison group participated in a flexibility program twice weekly for four months. Strength changes were assessed for the upper body (bench press), lower body (leg press), and the core (abdominal curl-ups). Body composition, including BMD, was measured by dual energy x-ray absorptiometry. Over the four-month study, the resistance training group demonstrated a 36.7% increase in bench press, a 31.1% increase in leg press, and a 222.6% increase in abdominal curl-ups (p < 0.05). The flexibility group improved by 7.7% for bench press, 6.6% for leg press, and by 43.0% for abdominal curl-ups (p < 0.05). Group*period interactions were significant for the leg press, bench press, and abdominal curl-ups (p < 0.05). Both groups decreased in body weight, body fat percentage, and fat tissue (p < 0.05). Neither group significantly changed in lean tissue, whole body BMD, and hip BMD (p > 0.05). Group*period interactions were not significant for any body composition outcome (p > 0.05). These results suggest that a twice weekly resistance training program is superior to flexibility training to increase strength; however, resistance training may not be enough to influence body composition to a greater extent than flexibility training in postpartum women. More research is warranted.
College and Department
Life Sciences; Exercise Sciences
BYU ScholarsArchive Citation
Pratt, Katherine Bishop, "The Effects of Resistance Training on Strength and Body Composition in Postpartum Women" (2010). All Theses and Dissertations. 2316.
body weight, body fat percentage, bone mineral density, weight retention, pregnancy