How strong is the evidence for Running?

A meta-analysis and large cohort study both show that running, even in modest weekly amounts, is associated with meaningfully lower all-cause and cardiovascular mortality compared to not running, and broader cardiorespiratory fitness meta-analyses support the same general pattern. That evidence is currently rated strong (70/100), built on 4 published studies, including 2 meta-analyses -- enough for real confidence in the effect.