Resistance training vs aerobic exercise — which matters more for longevity?

These aren't really competitors — they protect against different failure modes of aging, and the strongest expert guidance (NSCA, ICFSR consensus statements) recommends both rather than picking one. Resistance training's unique, well-replicated case is preserving muscle mass, strength and bone density with age — directly linked in meta-analyses to lower fall risk and better long-term function, particularly in older adults with sarcopenia. Aerobic exercise's case is cardiovascular and metabolic: consistent evidence for better blood pressure control, cardiorespiratory fitness, and outcomes in hypertensive and heart-failure populations, from both randomized trials and broader reviews. Evidence quality is high and comparable for both. If you have to prioritize one, resistance training is the more commonly neglected of the two as people age, even though the evidence supports doing both.