Most Americans already know they should do some form of resistance exercise. Most do not — surveys consistently find that fewer than 25 percent of American adults meet current physical activity guidelines for both aerobic and muscle-strengthening activities. One barrier is uncertainty: how much is enough? How much is too much? Does an hour a week matter? Two hours? Five?
A massive new study from Harvard T.H. Chan School of Public Health, published June 2, 2026 in the British Journal of Sports Medicine and widely reported this week, has answered that question with unusual precision — tracking nearly 150,000 American adults across three landmark long-running studies for up to three decades to determine exactly how much weekly strength training is associated with the greatest reduction in risk of death.
The answer is 90 to 119 minutes per week — roughly 1.5 to 2 hours, spread however works best for the individual. Compared to participants who did no strength training at all, those who strength-trained for 90 to 119 minutes per week had a 13 percent lower risk of dying from any cause. The same group had a 19 percent lower risk of dying from cardiovascular disease — the most common cause of death in the United States — and a remarkable 27 percent lower risk of dying from neurological conditions such as dementia and Parkinson's disease.
Perhaps most useful for the many Americans who worry that they might be "overdoing it" at the gym: no additional reduction in mortality risk was observed above 120 minutes per week. The longevity benefit plateaued. More was not better. This finding has important practical implications: it means that a person who finds time for three 30- to 40-minute strength sessions per week has captured essentially the same mortality reduction as someone training twice as long.
How the Study Was Conducted
The research, led by Yiwen Zhang, Dong Hoon Lee, Leandro F.M. Rezende, Yuan Ma, and Edward Giovannucci at Harvard Chan School, drew on three long-running American cohort studies: the Health Professionals Follow-Up Study, the Nurses' Health Study, and the Nurses' Health Study II. Participants reported their exercise habits via periodic questionnaires every two to four years over follow-up periods of up to 30 years. The enormous sample size — 147,000 adults — provided the statistical power to detect precise dose-response relationships between strength training volume and specific causes of death with high confidence.
Of note, 35,798 participants died over the 30-year follow-up period, providing a large event base for robust mortality analysis. The researchers adjusted carefully for factors that could confound the relationship between exercise and death, including age, diet, smoking, body weight, alcohol use, and other physical activity.
A striking additional finding concerned cancer mortality: participants who performed just 1 to 29 minutes of strength training per week had a 21 percent lower risk of death from cancer compared to those who did none, and those doing 30 to 59 minutes had an 18 percent lower risk. The cancer mortality benefit appeared at even lower doses than the cardiovascular and neurological benefits, suggesting that even minimal regular strength training offers meaningful cancer protection.
The Most Powerful Finding: Combining Strength and Aerobic Exercise
While the strength training benefits were substantial on their own, the study's most dramatic finding concerned what happens when strength training is combined with aerobic exercise. Among participants who met both the aerobic exercise guidelines (approximately 150 minutes per week of moderate-intensity activity) and the strength training sweet spot (90 to 119 minutes per week), the combined benefits were significantly larger than either exercise modality alone. This combination approached the upper bounds of what lifestyle-based longevity interventions have ever been shown to achieve in large population studies.
"It is important to engage in aerobic exercise that increases the heart rate. This new study finds that another important aspect of exercise is strength training," said Dr. Clarinda Hougen, a primary care sports medicine specialist at Cedars-Sinai Orthopedics, in comments to Healthline. "Including free weights, weight machines, and body weight exercises."
The practical prescription for most adults is achievable without a gym membership: bodyweight exercises (pushups, squats, lunges, planks), resistance bands, or basic free weights used three times per week for 30 to 40 minutes per session are sufficient to reach the 90 to 119 minute sweet spot. No advanced gym equipment, no personal trainer, and no high-intensity programming are required.
Frequently Asked Questions
Q: How much strength training does the Harvard study recommend for maximum longevity benefit?
A: 90 to 119 minutes per week — about 1.5 to 2 hours — spread across however many sessions fit your schedule. The benefit plateaued above 120 minutes per week: more was not better.
Q: How much does strength training reduce mortality risk?
A: In the 30-year study of 147,000 adults, 90–119 minutes per week of strength training was associated with: 13% lower all-cause mortality, 19% lower cardiovascular disease mortality, and 27% lower neurological disease mortality compared to no strength training.
Q: Do I need a gym to benefit from strength training?
A: No. Bodyweight exercises (pushups, squats, lunges, planks), resistance bands, and basic free weights at home are all effective forms of resistance training. The study tracked any form of strength or resistance exercise.
Q: Is combining strength training with cardio even better?
A: Yes. The study found that participants who did both — approximately 150 minutes per week of aerobic exercise and 90–119 minutes of strength training — had significantly greater mortality reductions than either exercise type alone.
Q: What types of activities count as strength training?
A: Free weights, weight machines, bodyweight exercises (pushups, squats, lunges), resistance bands, yoga involving resistance (like warrior poses), Pilates, and similar activities that engage muscles against resistance. The key is engaging muscles with enough resistance to require effort.
