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

Objectives: 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.

Methods: 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).

Results: 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.

Conclusion: 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.

Trial registration: ClinicalTrials.gov NCT01993953.

Keywords: Group training; Health- and fitness center; Lean body mass; Strength endurance; Women.