Is Walking good for longevity?

Yes — the evidence for this is strong. Walking and daily step count are supported by a large meta-analysis linking higher step counts to lower all-cause and cardiovascular mortality, alongside decades-old but influential cohort data (the Harvard alumni study) and broader reviews on physical activity and mortality. That's reflected in an evidence score of 78/100 for its role in longevity, drawn from 4 studies, with an estimated impact on longevity rated substantial (78/100).