Introduction: Weight loss achieved via energy restriction leads to muscle mass and bone mineral density (BMD) loss. High-intensity resistance and impact training (HiRIT) might attenuate weight loss-induced musculoskeletal declines. Our objective was to compare changes in body composition and metabolic and musculoskeletal health in older adults with obesity undertaking weight loss combined with HiRIT or aerobic training (AT).
Methods: Sixty older adults with obesity (aged >60 years; body fat percentage ≥30% in men and ≥40% in women) and a mobility limitation (short physical performance battery score [SPPB] <11) were randomly assigned to either 12 weeks of supervised, centre-based HiRIT, or self-directed, home-based AT, with energy restriction (750-1000kcal reduction in energy intake). Changes in physical function (primary outcome: gait speed), body composition, and metabolic and bone health were compared within and between groups.
Results: Gait speed increased in HiRIT compared with AT, chair stand times decreased in both groups, and handgrip strength and SPPB scores increased in HiRIT, but not AT (Figure). Similar decreases in total body mass (HiRIT: -5.1±4.6kg versus AT: -4.9±4.5kg), fat mass (HiRIT: -3.6±3.7kg versus AT: -3.3±3.6kg), visceral fat (HiRIT: -32.1±41.6cm2 versus AT: -31.4±39.9cm2) and appendicular lean mass (HiRIT: -0.8±1.6kg versus AT: -1.2±1.6kg) were observed. Only HiRIT reduced fasting glucose (HiRIT: -0.4±0.8mmol/L versus AT: -0.2±0.8mmol/L), insulin (HiRIT: -3.3±4.7mU/L versus AT: -1.5±4.7mU/L) and glycated haemoglobin (HiRIT: -0.2±0.4% versus AT: -0.1±0.4%). There were no significant within- or between-group differences in BMD. HiRIT was well-tolerated and accepted with only 7 minor adverse events (AT=5) and 6 participants lost to follow-up (AT=5).
Conclusion: HiRIT appears to be safe and more effective than AT for improving physical performance in older adults with obesity during weight loss. Additional trials with larger sample sizes and longer durations are warranted to explore whether HiRIT can improve metabolic health and attenuate weight loss-induced bone loss.