Long-Term effects of Progressive High-Speed Resistance Exercise in Older Women with Low Muscle Strength. A Randomized Clinical Trial.

Low muscle strength and sarcopenia are strong predictors of disability. Although multicomponent training (MT) is commonly recommended, its long-term effects remain unclear, and evidence on High-Speed Resistance Training (H-RT) in older women is limited. This double-blind randomized trial evaluated the effects of a 32-week intervention, with RT (weeks 1-11) progressing to H-RT (weeks 12-32) vs MT, on muscle strength, body composition, and functional performance. A total of 120 women aged ≥65 years (mean age: 77.0 ± 6.8 years) with low muscle strength (diagnosed with probable sarcopenia according to EWGSOP2) were randomized into H-RT, MT, or a non-exercise control group (CG). Both exercise modalities improved lower-limb physical performance, as assessed by the Five Times Sit-to-Stand Test, compared to women who did not exercise (p < 0.001), with no significant differences between H-RT and MT (p = 0.127) (H-RT: -3.2 ± 2.5 s; MT: -2.6 ± 2.5 s vs CG: -0.8 ± 2.1 s). Functional and body composition improvements were seen in both groups. H-RT led to greater improvements in the Timed Up & Go Test (-0.9 ± 1.9 s; p = 0.007) and waist circumference (-4.5 ± 5.1 cm; p = 0.010), while MT showed better results in aerobic capacity (Two-minute step test: +19.9 ± 17.2 steps; p = 0.044). H-RT is an effective alternative to MT for improving strength, performance, and body composition in older women, with specific benefits. Further studies should confirm its role in preserving intrinsic capacity and preventing sarcopenic obesity.