Beyond muscle mass: How strength training enhances health-related quality of life in older adults through functional improvement

Sarcopenia, the loss of muscle mass and strength/function with age, can diminish health-related quality of life (HRQoL), but may be prevented with exercise. The purpose of this study was to explore whether improvements in sarcopenia components are associated with improvements in HRQoL, and whether strength (ST) or power/agility training (PT) specifically may elicit more improvements in sarcopenia components and HRQoL. In this non-randomised control trial, 85 community-dwelling adults (mean age ± SD, 67.7 ± 6.8) completed either ST (n = 56) or PT (n = 29) for 16 weeks within the Golden Age exercise program, El Paso, USA . Appendicular lean mass (ALM) (via dual-energy X-ray absorptiometry [DXA], muscle strength (via hand grip strength [HGS]), physical performance (via gait speed and timed up and go [TUG] test), and HRQoL (via Assessment of Quality of Life [AQoL-4D] were assessed. Sarcopenia was diagnosed using the European Working Group on Sarcopenia in Older People (EWGSOP2) and the Sarcopenia Definitions and Outcomes Consortium (SDOC) criteria. Baseline sarcopenia prevalence was 0% according to EWGSOP2 criteria in both groups. Using SDOC criteria, prevalence was 1.8% overall (ST: n = 1, PT: n = 0). Neither definition detected sarcopenia at posttest. From baseline to follow-up, while ST saw significant increases in all sarcopenia components ( P < 0.001), PT showed significant improvements in HGS ( P = 0.002), GS, and TUG (both P < 0.001) but not lean mass ( P > 0.05). Overall HRQoL (utility score) and its senses dimension improved significantly in the ST group ( P = 0.009 and P = 0.029, respectively) but not in the PT group ( P = 0.726 and P = 0.310). Improved UG time (indicating improved mobility) correlated positively with enhanced HRQoL in the relationships dimension among ST participants (r = -0.285, P = 0.033). Changes in HGS or lean mass showed no significant associations with HRQoL changes in either group (all P > 0.05). ST, but not PT, was linked to improved overall HRQoL and its senses dimension. Notably, this improvement correlated with changes in physical performance (as measured by TUG) rather than with alterations in muscle strength or lean mass.