Abstract

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.

Degree

College and Department

Life Sciences; Exercise Sciences

Rights

http://lib.byu.edu/about/copyright/