Regular strength training could help people live longer, but a major new study suggests there may be an optimal amount. Researchers analyzing decades of health data found that one to two hours of resistance exercise per week was associated with the greatest reduction in the risk of premature death.
The findings add to growing evidence that strength training provides benefits beyond building muscle. While aerobic exercise remains the strongest predictor of longevity, combining regular cardio with moderate amounts of resistance training appears to offer the greatest protection against early mortality.
Large Cohorts Underpin New Findings
The study, led by researchers at the Harvard T.H. Chan School of Public Health, analyzed data from 147,374 participants enrolled in three major U.S. cohort studies: the Health Professionals Follow-up Study, the Nurses’ Health Study, and the Nurses’ Health Study II.
Participants were followed for up to three decades and regularly reported their physical activity habits, including resistance exercises such as weightlifting, squats, and bodyweight workouts. Researchers then compared these exercise patterns with mortality records, examining both all-cause mortality and deaths from specific diseases.
The analysis found that individuals who performed 90 to 119 minutes of strength training per week had a 13% lower risk of death from any cause compared with those who performed no resistance exercise.
Interestingly, the benefits appeared to level off beyond approximately two hours per week, suggesting that longer strength-training sessions did not provide additional longevity advantages.
Aerobic Exercise Remains The Strongest Predictor Of Longevity
Although resistance training was associated with meaningful health benefits, aerobic exercise produced the largest reductions in mortality risk.
People who accumulated at least 45 metabolic equivalent (MET) hours of aerobic activity per week experienced a 42% to 47% lower risk of death, regardless of the amount of strength training they performed.
MET, or metabolic equivalent of task, is a measure of energy expenditure. For example, 150 minutes of moderate-intensity aerobic exercise per week is equivalent to approximately 7.5 MET-hours.
The findings reinforce longstanding public health recommendations that emphasize regular cardiovascular activity as a cornerstone of healthy aging and disease prevention.
Combining Cardio And Strength Training Produced The Best Results
The lowest mortality risk was observed among participants who consistently combined both aerobic exercise and resistance training.
Researchers found that individuals performing 30 to 44 MET-hours of aerobic activity alongside 60 to 119 minutes of strength training per week had approximately a 45% lower risk of death compared with inactive individuals.
While either form of exercise alone was beneficial, aerobic activity generally produced larger reductions in mortality risk. However, the combination of both appeared to provide the most comprehensive protection, particularly for cardiovascular and neurological health.
The findings suggest that strength training should complement, rather than replace, regular aerobic exercise.
Cardiovascular And Neurological Benefits Were Particularly Strong
Participants who engaged in 90 to 119 minutes of weekly resistance training were 19% less likely to die from cardiovascular disease than those who performed no strength training.
The benefits were even more pronounced for neurological causes of death. Individuals in this activity range had a 27% lower risk of dying from neurological disorders, including conditions such as Alzheimer’s disease.
These results add to a growing body of research suggesting that resistance exercise may support not only physical function and metabolic health but also long-term brain health.
Researchers note that maintaining muscle mass, strength, and physical activity throughout adulthood may help preserve mobility, independence, and cognitive function later in life.
Study Limitations And Future Research
The authors caution that the study was observational and therefore cannot prove that strength training directly causes longer life.
Physical activity levels were self-reported, which introduces the possibility of recall errors or inaccurate reporting. In addition, the study population consisted primarily of health professionals, who may have healthier lifestyles overall than the general population.
Despite these limitations, the study’s exceptionally large sample size and long follow-up period make the findings particularly valuable for understanding the long-term effects of exercise habits.
The research team plans to investigate how different combinations of aerobic and resistance training influence not only lifespan but also healthspan—the number of years people remain healthy, active, and independent as they age.
What The Findings Mean For Public Health
The results support current exercise guidelines recommending that adults participate in both aerobic and muscle-strengthening activities each week.
For most people, the findings suggest that one to two hours of strength training, combined with regular cardiovascular exercise, may be sufficient to achieve meaningful longevity benefits.
Researchers also believe that optimal amounts of resistance training may differ depending on the specific health outcome being considered. Future studies could help refine these recommendations and allow clinicians to provide more personalized exercise advice.
The study was published in the British Journal of Sports Medicine.
