Effects of a 16-week high-speed resistance training program on isokinetic muscle strength parameters in older adults

Abstract

Objectives: This study investigated the effects of a 16-week high-speed resistance training program on isokinetic muscle strength parameters. Methods: Seventy-nine independent older adults, who were divided into an intervention group (IG, N=40, age: 68.5 ± 3.5 years) and a control group (CG, N=39, age: 72.1±5.9 years) participated in the study. The program lasted 16 weeks, with three sessions per week with 50–60min. Each session being comprised of five-six exercises, two-three sets, and six–ten reps/exercise. In-tensity increased progressively based on movement velocity (>1.3 to 0.75 m/s), representing approximate-ly 20% to 65% of one repetition maximum. All exercises were performed as fast as possible over the con-centric phase, monitored through BEAST™ sensors, followed by a controlled 2–3 second eccentric phase. The CG maintained daily activities, tracked by the IPAQ Questionnaire. Bilateral isokinetic strength of the knee extensors and flexors at 60˚/s and 180˚/s was assessed pre- and post-intervention using the Biodex© 3 dynamometer. Results: After the intervention, ANCOVA results showed significant improvements in favor of IG in peak torque for extension on the dominant (p<0.001; η²p=0.215) and non-dominant side (p<0.001; η²p=0.290) and for flexion on the dominant (p<0.001; η²p=0.290) and non-dominant side (p=0.002; η²p=0.125). Similarly, significant enhancements in favor of IG were found in average muscle power for extension on the dominant (p<0.001; η²p=0.328) and non-dominant side (p<0.001; η²p=0.298) and for flexion dominant (p<0.001; η²p=0.284) and non-dominant side (p=0.005; η²p=0.100). Conclusion: This study demonstrates the HSRT program's potential to significantly enhance muscle strength and power in older adults. Additionally, these findings underscore the importance of integrating HSRT into clinical practice, with individualized prescriptions and real-time feedback for improving engagement in exercise interventions.