Effects of a 16-Week High-Speed Resistance Training Program on Isokinetic Muscle Strength Parameters and Health-Related Quality of Life in Independent Older Adults: A Clinical Trial

This study investigated the effects of a 16-week high-speed resistance training (HSRT) program on isokinetic muscle strength parameters and, secondarily, on health-related quality of life (HRQOL). Seventy-nine independent older adults were assigned to an intervention group (IG) and a control group (CG). The IG completed supervised HSRT three times per week, while the CG received no intervention. Each session lasted 60–70 minutes and included 5–6 exercises of 2–3 sets at maximal concentric speed and a controlled eccentric phase (≈2–3 seconds). Isokinetic muscle strength was assessed pre- and post-intervention using isokinetic testing of knee extensors (KE) and flexors (KF) at 60º/s and 180º/s on dominant (DS) and non-dominant sides (NDS). The HRQOL was measured using the SF-36 questionnaire. The IG demonstrated significant improvements in peak torque for KE-DS (∆change: 14.02 Nm; p < .001; ηp2 = 0.215), KE-NDS (∆change: 16.19 Nm; p < .001; ηp2 = 0.290), KF-DS (∆change: 8.06 Nm; p < .001; ηp2 = 0.290), and KF-NDS (∆change: 8.33 Nm; p = .002; ηp2 = 0.125), as well as in average muscle power for KE-DS (∆change: 15.51 W; p < .001; ηp2 = 0.328), KE-NDS (∆change: 17.33 W; p < .001; ηp2 = 0.298), KF-DS (∆change: 8.21 W; p < .001; ηp2 = 0.284), and KF-NDS (∆change: 8.06 W; p = .005; ηp2 = 0.100). HRQOL improvements were also observed. The present HSRT protocol effectively improves isokinetic muscle parameters and HRQOL measures in older adults.