Research based on 80,000 adults finds those who strength trained for roughly 90–120 minutes weekly showed lower mortality risk — but experts caution the work is observational and not a prescription
The longevity payoff from lifting weights has a shape, and it is not the one most people assume. A study published last week in the British Journal of Sports Medicine suggests that the mortality benefit of resistance training climbs quickly, plateaus around 90 to 120 minutes a week, and then flattens. Going harder did not appear to add more years in the analysis.
Researchers tracked adults and compared those who did no strength training with those who lifted. Participants who logged roughly 90 to 119 minutes of resistance work per week had a 13 percent lower rate of death from any cause than those who did none, the study found. Beyond about 120 minutes a week, the curve bent. More time in the weight room did not translate into meaningfully lower mortality.
The shape matters because the standard public-health floor already sits inside the effective range. The World Health Organization and the U.S. Department of Health and Human Services both recommend that adults do muscle-strengthening activity at least twice a week, alongside 150 minutes of moderate aerobic activity. Two short sessions can easily reach 90 minutes when warm-up, working sets, and rest are counted. The new dose-response data suggest that this familiar baseline is not the bare minimum. It is already in the zone where the longevity signal is strongest.
What the data do not support is treating 90 to 119 minutes as a target line. The researchers explicitly warned against that framing. "Importantly, 90 to 120 minutes per week should not be interpreted as a strict target or threshold," said lead author Yiwen Zhang, a postdoctoral research fellow at the Harvard T.H. Chan School of Public Health. Resistance training volume was self-reported, the design was observational rather than a randomized trial, and the apparent benefit is entangled with other healthy behaviors: people who lift twice a week also tend to sleep better, eat differently, and move more outside the gym. The 13 percent figure is the size of the association, not a clean causal effect.
The mechanism story is not in doubt. Resistance work improves glucose metabolism, slows the age-related loss of muscle mass, and supports bone density in ways that aerobic exercise alone does not. It is also linked in separate research to lower rates of depression and anxiety, which is part of why the all-cause mortality finding shows up at all. The benefit is biological and psychological at once, which is one reason a small dose appears to buy a meaningful amount of protection.
For someone who has been putting off strength work because it feels like a separate, time-consuming practice, the practical read is simple. Two sessions a week, totaling somewhere between an hour and a half and two hours, lands inside the range where the new analysis sees the largest mortality benefit. "Even doing as little as half an hour or less each week is linked to a lower risk of dying from any cause," said co-author Edward Giovannucci, a professor of nutrition and epidemiology at the Harvard T.H. Chan School of Public Health, so the entry point is lower than the ceiling suggests.
Two independent experts not involved in the study found the results consistent with the broader literature. In general, the scientific evidence indicates that "anywhere from 30 to 60 minutes" of muscle-strengthening exercise per week can result in a reduction of about 10 to 20 percent in all-cause mortality, said Zachary Pope, an assistant professor at the University of Oklahoma. "The evidence is clear on this one," said Jess Gorzelitz, an assistant professor at the University of Iowa, who studies behavioral interventions to promote exercise. "It's not saying that you should do strength training instead of aerobic exercise. It really is a combination of the two."
What to watch next: the underlying study was published in early release in May 2026 in the British Journal of Sports Medicine, and the dose-response window will be tested against other cohorts. The 13 percent figure is large enough that replication matters, and researchers have been clear that a future finding of a different optimal window would not be surprising. Until then, the floor and the ceiling both point in the same direction: a modest, consistent dose is doing more work than the gym culture suggests, and the marginal hour is not the one that matters.