The safety of exercise training in multiple sclerosis: a systematic review.

There are many reviews documenting the benefits of exercise training among persons with multiple sclerosis (MS). To date, we are unaware of a review that summarizes the risks of relapse and other adverse events (AEs) associated with exercise training, yet this is critical for informing decisions and recommendations regarding the safety of this behavior. We conducted a systematic review of relapse and other AEs reported in randomized controlled trials (RCTs) of exercise training in MS. We searched electronic databases for RCTs of exercise training in MS. We calculated the rate of relapse and AEs, and the relative risk of relapse and AEs for exercise training versus control. Twenty-six studies were reviewed that included 1295 participants. We determined that the rate of relapse was 6.3% and 4.6% for control and exercise, respectively. The rate of AEs was 1.2% and 2.0% for control and exercise, respectively. The relative risk of relapse for exercise training was 0.73, whereas the relative risk of AE for exercise training was 1.67. Exercise training was not associated with an increased risk of relapse, and risk of AEs was not higher than in healthy populations. This evidence should alleviate uncertainty regarding the safety of exercise training in MS.