Exercise and calorie restriction provide greater beneficial effects than much of the array of therapies making up modern medicine; this is a measure of just how much work is left to do in medical research. There remain many conditions for which only marginal, palliative treatments exist. It is a strange era we live in: that this can be the case on the one hand, and yet on the other the research community is just a few decades away from being able to cure all cancer, grow organs from a patient's cells, and create rejuvenation therapies that will greatly extend healthy life.
To determine the comparative effectiveness of exercise versus drug interventions on mortality outcomes [we] combined study level death outcomes from exercise and drug trials using random effects network meta-analysis.
We included 16 (four exercise and 12 drug) meta-analyses. Incorporating an additional three recent exercise trials, our review collectively included 305 randomised controlled trials with 339,274 participants. Across all four conditions with evidence on the effectiveness of exercise on mortality outcomes (secondary prevention of coronary heart disease, rehabilitation of stroke, treatment of heart failure, prevention of diabetes), 14,716 participants were randomised to physical activity interventions in 57 trials.
No statistically detectable differences were evident between exercise and drug interventions in the secondary prevention of coronary heart disease and prediabetes. Physical activity interventions were more effective than drug treatment among patients with stroke. Diuretics were more effective than exercise in heart failure. Inconsistency between direct and indirect comparisons was not significant.
Although limited in quantity, existing randomised trial evidence on exercise interventions suggests that exercise and many drug interventions are often potentially similar in terms of their mortality benefits.