Scientists Find the Strength-Training Sweet Spot for a Longer Life: 90 to 120 Minutes a Week

It turns out you may not need to live in the gym to reap the life-extending benefits of lifting weights. A large new study has identified a strength-training "sweet spot" — roughly 90 to 120 minutes a week — that delivers some of the biggest long-term health rewards, with little to gain from doing more.

The research, published online in the British Journal of Sports Medicine and led by scientists at the Harvard T.H. Chan School of Public Health, tracked more than 147,000 people for up to 30 years. It is among the largest and longest efforts to date to pin down exactly how much resistance exercise is enough to move the needle on longevity.

Participants 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 did none, the analysis found. The same range was associated with a 19% lower risk of dying from cardiovascular disease and a striking 27% lower risk of death from neurological disease — a category that includes conditions such as Alzheimer's and Parkinson's.

Crucially, the benefits plateaued. No additional reduction in death risk was observed above 120 minutes per week, suggesting that more time under the barbell does not translate into proportionally more protection. For people intimidated by the idea of long daily workouts, the message is encouraging: two relatively short sessions a week may be all that is required to capture most of the upside.

The findings dovetail with a growing body of evidence that muscle-strengthening activity — long overshadowed by running, cycling and other aerobic exercise — plays its own distinct role in healthy aging. Resistance training helps preserve muscle mass and bone density, improves metabolic health and supports balance and mobility, all of which become more important with age. The new data add hard numbers on mortality to that picture, and the link to a sharply lower risk of neurological death is likely to draw particular interest from researchers studying how physical activity protects the aging brain.

The researchers also found that combining strength workouts with aerobic exercise produced even stronger benefits than either alone, reinforcing public-health guidance that recommends a mix of the two. While observational studies like this one cannot prove that lifting weights directly causes people to live longer, the size, duration and consistency of the results make a compelling case. For anyone weighing how to spend limited workout time, the study offers an unusually concrete target — and a reassuring ceiling.