Effects of a 16-week high-speed resistance training program on the rate of torque development in older adults: A clinical trial

Abstract

Introduction: Aging is often associated with a decline in muscle strength, driven by factors such as neural alterations leading to reduced voluntary muscle activation (Manini & Clark, 2012). These changes negatively impact physical performance and increase the risk of functional limitations in older adults. Objectives: This study aimed to evaluate the effects of a 16-week High-Speed Resistance Training (HSRT) program on Rate of Torque Development (RTD) in independent older adults. Methods: This clinical trial involved 79 older adults, who were randomly assigned to either an intervention group (IG, N=40, 68.50 ± 3.54 years) or a control group (CG, N=39, 72.08 ± 5.89 years). The IG participated in supervised HSRT sessions three times per week for 16 weeks, while the CG did not engage in any structured exercise program. Each HSRT session lasted 60–70 minutes and comprised 5–6 exercises, with 2–3 sets of 6–10 repetitions. The concentric phase of each exercise was performed as quickly as possible and monitored using a BEAST™ sensor (Beast Technologies, Brescia, Italy). Peak RTD and RTD time intervals were assessed for knee extension and flexion, both pre- and post-intervention, using an isokinetic dynamometer (Biodex System 3) with three trials at 60º/s. Results: ANCOVA revealed significant group effects favoring the IG after the intervention for peak RTD in knee extension, on both the dominant (η²p=0.134) and non-dominant side (η²p=0.237), as well as for knee flexion on the dominant (η²p=0.226) and non-dominant side (η²p=0.131). Significant differences were also found for RTD time intervals between groups. Significant differences were also found for RTD time intervals between groups. For knee extension, significant differences were observed in RTD0-30, RTD0-60, RTD0-80 on the dominant side (η²p=0.158, 0.178, and 0.119, respectively), and RTD0-30 and RTD0-60 on the non-dominant side (η²p=0.211 and 0.193, respectively). For knee flexion, significant effects were found for the dominant side in RTD0-30 and RTD0-80 (η²p=0.070 and 0.062, respectively) and for the non-dominant side in RTD0-30 (η²p=0.079). Discussion and Conclusion: These findings are clinically meaningful, indicating that HSRT can significantly improve or help prevent the decline in both the magnitude and speed of muscle strength generation in older adults. The ability to rapidly generate force plays a critical role in reducing the risk of falls (Pijnappels et al., 2008), as it is essential for quickly repositioning the lower limbs and maintaining postural control (Miszko et al., 2003). In conclusion, this clinical trial highlights the substantial potential of the HSRT program to significantly enhance muscle force production capacity, making it a valuable intervention for older adults to preserve functional independence.