Effects of Weight-Bearing Resistance Training With Explosive Motions on the Rate of Force Development in Community-Dwelling Older Adults: A Randomized Controlled Trial.

Background: Eliminating risk factors for falls leads to reduction of the incidence of frailty. The recommended training program used only body weight resistance and no equipment to prepare for quick movements in daily living in community-dwelling older adults is unknown. Thus, we compared the effects of weight-bearing resistance training with (WEM) and without explosive motions (WOEM).

Methods: Sixty older adults were randomly assigned to WEM and WOEM groups. The WEM group performed the concentric phase during repetitions quickly and the WOEM group performed it at traditional velocity. The designated training programs consisted of 8 events to train the whole body for 50 minutes twice a week for 12 weeks. The changes in the rate of force development of toe grip, single knee extension, and flexion from baseline to 12 weeks were measured. Between-group differences were analyzed for changes in each outcome variable.

Results: Twenty-seven participants in the WEM group (70 [5] y) and 21 participants in the WOEM group (69 [4] y) completed the study. The change in the early rate of force development of toe grip from baseline to 12 weeks was significantly greater in the WEM group (0-30 ms: effect size = 0.53, 95% CI = 6.36-68.10, P = .049; 0-50 ms: effect size = 0.56, CI = 10.05-86.02, P = .046) than in the WOEM group.

Conclusions: Weight-bearing resistance training with explosive motions has the advantage of not being limited to tools and places. Therefore, it is more suitable than traditional repetition velocity training for quick movement by increasing rate of force development in community-dwelling older adults before they become frail.