Is Zone 2 worth prioritizing?

"Zone 2 training" (low-intensity aerobic exercise performed just below the first lactate/ventilatory threshold) has become a popular longevity concept, but the best current evidence is considerably more skeptical of the specific claim than the popular narrative suggests. Weighing that against the numbers, Zone 2 is not a priority based on current data — the evidence is only emerging (38/100), and its estimated impact (22/100) is on the lower end too.