Project R-15187

Stair-climbing versus machine-based resistance exercise to improve muscle power among older adults (Research)

Machine-based resistance training (RT) can reduce the age-related loss in muscle power (Pmax). However, weight-bearing exercises have a higher potential for large-scale implementation. This study investigated whether stair-climbing exercise (STAIR) was non-inferior to improve Pmax compared to machine-based RT among older adults. Functional capacity and cognition were in-cluded as secondary outcomes. Community-dwelling older adults (30♂, 16♀; 70.9 ± 4.3 years) were randomly assigned to RT or STAIR (n=23/group). Supervised lab-based training sessions were performed twice weekly for 12 weeks. In week 1-4, exercises were performed at controlled speed (hypertrophy-oriented; 4x12-15 repetitions; 55% of one-repetition maximum (1-RM) in RT; step-up exercise with height of 30-40 cm in STAIR), in week 5-12 as fast as possible (power-oriented, 4x12 repetitions; 40% of 1-RM for RT and 4x2 flights of 6 steps for STAIR; +10% load from week 9 on-wards in both groups). Leg-extensor Pmax, functional capacity and cognition were measured pre and post intervention, and Pmax also after 4 weeks of training. Pmax tended to increase more in RT versus STAIR (19.5 ± 12.2% versus 13.7 ± 16.5%, d = 0.39, p = 0.086). Non-inferiority analyses of Pmax were inconclusive. All functional capacity tests showed a significant improvement over time (p < 0.05). STAIR increased more in stair ascent performance (d = 0.45-0.61, p < 0.05) than RT, while similar improvements in both groups were found for 10-m fast walk, 5-repetition sit-to-stand per-formance and countermovement jump height (interaction effect: p > 0.05; time effect: p < 0.05). In contrast to the work of Yoon et al. (2017, 2018) on power training in older adults with cognitive frailty or mild cognitive impairment, neither RT nor STAIR induced significant gains in general cognitive performance and executive function in our cognitively healthy sample (p > 0.05). However, similar improvements in digit span test forwards were found in RT and STAIR (time effect: p = 0.004). To conclude, STAIR and RT both induced significant changes in Pmax and functional capacity in older adults. Although RT tended to be superior for gains in leg-extensor power, STAIR has a higher potential for implementation and might therefore be more effective in real life. Future research is necessary to investigate the optimal exercise dose and progression over a longer-term intervention and to examine the effects of STAIR when implemented in a home-based setting with limited expert oversight.

09 October 2024 - 11 October 2024