Optimal retraining time for regaining functional fitness using multicomponent training after long-term detraining in older adults

Objectives Little is known about the optimal retraining time for regaining functional fitness through multicomponent training following long-term detraining in older adults. This study first investigated the time course of functional fitness changes during 12-month multicomponent training, 12-month detraining, and 9-month retraining in 18 older adults (68.33 ± 3.46) and then determined the optimal retraining time for regaining the post-training functional fitness level after a 12-month detraining period. Methods Functional fitness, including lower and upper limb strength, lower and upper limb flexibility, aerobic endurance, and dynamic balance, was assessed at baseline, 12 months post-training, 12 months post-detraining, and 3, 6, and 9 months post-retraining. Results There were significant increases in all of the functional fitness components except upper limb flexibility at post-training and no significant decreases at post-detraining. For lower and upper limb strength and lower limb flexibility, a 3-month period was required to regain the post-training condition. For aerobic endurance and dynamic balance, a retraining period ≥9 months was necessary to regain the post-training functional fitness condition. Conclusions To regain the post-training condition of all functional fitness components, a retraining period ≥9 months was required. This information might be useful for health professionals to encourage older adults not to interrupt retraining until they regain their post-training functional fitness condition.