A meta-analysis included 9 datasets from RCTs with a total of 801 subjects. During a mean follow up of 705 days there were 88 (22%) deaths in the exercise arm and 105 (26%) in the control arm. Exercise training significantly reduced mortality (hazard ratio 0.65, 95% confidence interval 0.46 to 0.92). The secondary end point of death or admission to hospital was also reduced (HR 0.72, 95% CI 0.56 to 0.93). No statistically significant subgroup specific treatment effect was observed.
Another systematic review included 81 studies (30 RCTs, 5 nonrandomized controlled trials, 9 randomized crossover trials, and 37 longitudinal cohort studies). Exercise training was performed in 2387 patients. The average increment in peak oxygen consumption was 17% (95% CI 14% to 19%) in 57 studies that measured oxygen consumption directly (9% in 3 studies that only used strength training). There were no reports of deaths that were directly related to exercise during more than 60 000 patient-hours of training. The number of combined events (deaths or adverse events) during the training and follow-up periods of the RCTs was 56 in the exercise groups and 75 in the control groups (odds ratio [OR] = 0.98; 95% confidence interval [CI]: 0.61 to 1.32; P = 0.60). During the same period, 26 exercising and 41 nonexercising subjects died (OR = 0.71; 95% CI: 0.37 to 1.02; P = 0.06).