Effects of BodyPump and resistance training with and without a personal trainer on muscle strength and body composition in overweight and obese women—A randomised controlled trial

Abstract

Overweight and obese individuals are recommended to perform regular resistance training, and the health- and fitness industry offer several exercise programs with purpose to improve muscle strength and body composition. This randomised controlled trial aimed to compare 12 weeks (45-60min, 3 sessions/weeks) of popular exercise programs, available at health- and fitness centers worldwide. Previous untrained women with BMI≥25 were allocated to either BodyPump (a high-repetition group session) (n=25), individual resistance training with a personal trainer (n=25), non-supervised individual resistance training (n=21) and non-exercising control group (n=21). Primary outcome was one repetition maximum (1RM) in squat and bench press, and secondary outcome was body composition (Inbody720). The BodyPump group did not improve muscle strength, compared to any of the other groups. In 1RM squat, the personal trainer group increased 17% (95% CI 5.1-23.0), 20% (95% CI 7.5-24.8) and 30% (95% CI 15.8-33.0kg) more than the non-supervised group, BodyPump and controls, respectively. In bench press the personal trainer group increased 10% (95% CI 1.5-7.2) and 16% (95% CI 3.5-9.3kg) more compared to BodyPump and controls. No difference was found compared to the non-supervised group in bench press. There were no between-group differences in body composition. Twelve weeks of BodyPump did not improve muscle strength in overweight women, but a personal trainer amplified the effects of individual resistance training on maximal strength in squat. None of the intervention groups showed effect in body composition.