Strength / Resistance Training

Strength training earns a strong-recommend at 8.5 because it delivers an exceptionally broad set of proven benefits, led by lower mortality, at a benign safety profile and almost no financial cost. The practical verdict: for nearly everyone, two to four progressive sessions a week covering the major muscle groups is one of the best possible uses of time for lifelong health, and the required dose for the mortality benefit is smaller than most people assume. The score sits in strong-recommend rather than top-tier because the mortality evidence is observational and the intervention demands real, sustained time and technique, which is where most people fail rather than in the biology. If you can build the habit, the return is among the highest in the entire corpus.

✅ Best for: Older adults defending against sarcopenia, frailty, and falls, given the lean-mass and fall-prevention evidence in Peterson 2011 and Sherrington 2019; postmenopausal women targeting bone density under supervision after Watson 2018; anyone managing depressive or anxiety symptoms who wants an active adjunct; people with prediabetes or metabolic syndrome building the muscle that improves glucose disposal; and time-efficient generalists who want the highest-leverage single habit for healthspan and longevity.

❌ Avoid if: You have unstable or acute cardiac disease, uncontrolled hypertension, or proliferative retinopathy or recent eye surgery, where the blood-pressure spikes of heavy straining are risky, given how sharply resistance work moves blood pressure per Edwards 2023, until you have medical clearance; you have an acute injury to the muscle or joint you would be loading, which needs to heal or be rehabilitated first; or you are early post-surgery without a clinician's sign-off. Beginners should not skip the technique-learning phase, since progressing load faster than skill is the main source of preventable injury.