Objective: To test the hypothesis that lower extremity progressive resistance training (PRT) can improve muscle strength and functional capacity in patients with multiple sclerosis (MS) and to evaluate whether the improvements are maintained after the trial.
Methods: The present study was a 2-arm, 12-week, randomized controlled trial including a poststudy follow-up period of 12 weeks. Thirty-eight moderately impaired patients with MS were randomized to a PRT exercise group (n = 19) or a control group (n = 19). The exercise group completed a biweekly 12-week lower extremity PRT program and was afterward encouraged to continue training. After the trial, the control group completed the PRT intervention. Both groups were tested before and after 12 weeks of the trial and at 24 weeks (follow-up), where isometric muscle strength of the knee extensors (KE MVC) and functional capacity (FS; combined score of 4 tests) were evaluated.
Results: KE MVC and FS improved after 12 weeks of PRT in the exercise group (KE MVC: 15.7% [95% confidence interval 4.3-27.0], FS: 21.5% [95% confidence interval 17.0-26.1]; p < 0.05), and the improvements were better than in the control group (p < 0.05). The improvements of KE and FS in the exercise group persisted at follow-up after 24 weeks. Also, the exercise effects were reproduced in the control group during the 12-week posttrial PRT period.
Conclusions: Twelve weeks of intense progressive resistance training of the lower extremities leads to improvements of muscle strength and functional capacity in patients with multiple sclerosis, the effects persisting after 12 weeks of self-guided physical activity.
Level of evidence: The present study provides level III evidence supporting the hypothesis that lower extremity progressive resistance training can improve muscle strength and functional capacity in patients with multiple sclerosis.