Do 30–60 minutes of strength training a week

Moderate value
Evidence A
Buys life
Free
Takes some hours
Some willpower

In plain words

People who do 30–60 minutes of strength training a week have a 10% to 20% lower chance of dying over the same period than people who don't. More than that is not better. Doing strength and aerobic exercise together works best.

Cost: Bodyweight squats and push-ups cost nothing. 1–2 sessions a week, 20–30 minutes each. The hard part is putting it into your weekly schedule.
What you get: Pooling several follow-up studies (observational, not assigning groups): people who did strength training had 10%–17% lower risk of death than people who didn't. More is not always better. The reduction is largest at about 30–60 minutes a week, about 10%–20%, and training more adds no extra benefit. People who did both strength and aerobic exercise had lower risk of death than people who did neither.
Notes: These studies only followed people, and the amount of exercise was reported by the participants themselves. The evidence for the part about “overdoing it makes things worse” is very weak, so there is no need to limit your training for that reason. Strength training also helps older people prevent falls and keep muscle; that is covered in §1.
Evidence grade: A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.
Sources: Momma H 等 (2022). Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies. British Journal of Sports Medicine. https://doi.org/10.1136/bjsports-2021-105061

Mentioned in

Don't count on learning a “correct lifting posture” or taking a lifting course to prevent back pain; what to cut is the weight and number of lifts, and exercise regularly

Translated from the Chinese original. Original book, section 2, tip 16. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer