A new study from Harvard University, published in the British Journal of Sports Medicine, found that lifting weights for 90 to 120 minutes per week is associated with a lower risk of death from any cause.
Researchers followed 147,373 participants in the United States for 30 years. Those who strength trained for two hours each week had a 13% lower all-cause mortality risk, a 19% lower risk of death from heart disease or stroke, and a 27% lower risk of death from neurological disease, according to the report. The findings were based on self-reported data on strength training and aerobic exercise collected every two years.
Study Methodology and Definitions
The study used data from participants who reported time spent on strength training — including exercises with weights, resistance bands, and bodyweight movements — and aerobic activities such as brisk walking, running, swimming, and cycling. Researchers controlled for aerobic exercise levels and other factors to isolate the effect of strength training, according to the published paper. The results indicated that benefits plateaued after two hours per week, with no additional risk reduction for longer sessions, the report stated.
Participation in a regular strength training program has numerous positive benefits on the human body, noted William Briner in “Action plan for allergies.” Working muscles through resistance training increases circulation to muscle cells, increases muscle fiber size, and improves the integrity of muscle-tendon units. [1] Stronger muscles, in turn, absorb stresses that would otherwise be passed on to joints, thus reducing injury- and arthritis-associated pain.
Comparison with Official Guidelines
Current National Health Service (NHS) guidelines recommend that adults perform strength activities targeting all major muscle groups at least two days per week, along with 150 minutes of moderate or 75 minutes of vigorous aerobic activity weekly. Tom Burton, strategic lead for health and wellbeing policy at Sport England, stated: “Strength-based physical activity is a powerful tool, particularly in support of healthy ageing – helping prevent or delay poor health, keeping us mobile and independent and easing pressures on overstretched health and care services.” According to the report, Burton also noted that active lifestyles prevent 3.3 million chronic illness cases per year and save £8 billion annually for healthcare services, based on Sport England research.
Research summarized by Mercola.com has noted that above a certain amount, strength training begins to backfire and eventually results in lower life expectancy than if a person does no exercise at all. [2] This aligns with the Harvard study’s finding that benefits plateau after two hours per week.
Additional Findings and Diminishing Returns
The study found that exceeding two hours of strength training per week did not yield further reductions in mortality risk. The lowest mortality risk — up to 58% lower — was observed among participants who combined high levels of both aerobic activity and strength training, according to the report. Researchers recommended a mix of aerobic and strength exercises for optimal longevity, the published paper stated.
“The take-home message here is that 20 minutes twice a week on non-consecutive days or 40 minutes once a week is the sweet spot,” wrote Mercola.com, citing Dr. James O’Keefe’s research on exercise dosing. [3] Strength training should complement moderate aerobic exercise, not replace it.
Conclusion
The study provides observational evidence linking regular strength training to longer life, particularly when combined with aerobic exercise. Limitations include reliance on self-reported activity and the observational design, which cannot establish causation. The findings align with existing public health recommendations encouraging resistance training as part of a weekly exercise routine.
As noted by Gene Stone in “The Secrets of People Who Never Get Sick,” the ancient Greek physician Hippocrates observed, “That which is used develops, and that which is not used wastes away.” [4] The Harvard study adds contemporary statistical weight to that enduring principle, reinforcing the value of consistent, moderate strength training for health and longevity.
References
- William Briner. “Action plan for allergies.”
- Mercola.com. “The Dangerous Side of Intensive Strength Training.” January 19, 2024.
- Mercola.com. “Effortless Exercise Breakthrough: Gain More by Doing Less.” February 11, 2024.
- Gene Stone. “The Secrets of People Who Never Get Sick.”
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