Two Hours of Weights a Week Cuts Death Risk by 13%
A 30-year study of 147,374 people found 90–120 min of weekly strength training cuts all-cause mortality risk by 13%.
The Surprisingly Small Dose That Changes the Mortality Equation
Most people who avoid strength training cite the same reason: time. The image of a serious gym commitment — five days a week, two hours a session — keeps millions from ever starting. A large study published June 2 in the British Journal of Sports Medicine suggests that picture is badly distorted. For meaningful reductions in mortality risk, the actual dose is far smaller than most people assume.
The study tracked 147,374 participants across three long-running research cohorts over up to 30 years. Researchers looked at how much time participants devoted to both strength training and aerobic exercise every two years throughout the study period. What emerged from that mountain of data was a clear, specific sweet spot: 90 to 120 minutes of strength training per week — roughly two sessions of 45 minutes each — was associated with a 13% lower risk of death from any cause. Above 120 minutes per week, no additional benefit was detected.
What the Data Actually Covered
The three cohorts pulling the study’s weight were the Health Professionals Follow-up Study (1992–2022), the Nurses’ Health Study (2002–2021), and Nurses’ Health Study II (2003–2021). Of the 147,374 participants, 31,540 were male and 115,834 were female. The average age at enrollment was 54. Over the course of the study period, 35,798 participants died — a large enough number to draw statistically meaningful associations between exercise habits and mortality outcomes.
Aerobic exercise in the study covered brisk walking, running and jogging, swimming, cycling, tennis and squash, strenuous outdoor work, and stair climbing. Strength training included free weights, weight machines, and bodyweight movements such as push-ups, lunges, and squats. Worth noting: the study excluded calisthenics and Pilates from the strength training category, which means people who rely on those disciplines may not be fully represented in the findings.
Cardiovascular and Neurological Risk Reductions
The all-cause mortality figure of 13% is striking on its own, but the disease-specific numbers go further. The 90–120 minute weekly range was associated with a 19% lower risk of death from cardiovascular disease and a 27% lower risk of death from neurological disease. Those are not marginal differences.
The cancer picture looks different and deserves its own reading. Lower cancer mortality risk appeared only at lower weekly training volumes — a 9% reduction at 1 to 29 minutes per week, and 12% at 30 to 59 minutes per week. The association did not strengthen with more training time in the way cardiovascular and neurological risk did. Why cancer risk behaves differently in this data isn’t something the study resolves.
Clarinda Hougen, MD, a primary care sports medicine specialist at Cedars-Sinai Orthopedics in Los Angeles, was not involved in the research but commented on its findings. She noted that strength training builds muscle mass in ways that can improve metabolic health and reduce cardiovascular risk — a mechanism that helps explain why the cardiovascular mortality association is as strong as it is. “By training and growing your muscle mass, you can improve your metabolic health and help reduce cardiovascular risk,” she said.
Where the Study’s Limits Matter
This is an observational study, which means it cannot establish cause and effect. The association between strength training and lower mortality is real in the data, but the study cannot rule out that people who consistently lift weights for 30 years differ from non-exercisers in other important ways — diet, sleep, access to healthcare, general health-consciousness — that also affect longevity. That caveat matters before reading the 13% figure as a guarantee.
The data is also self-reported. Participants were asked every two years how much time they spent on strength training and aerobic activity. Self-reported exercise data tends to skew optimistic; people generally overestimate both frequency and duration. The study also had no information on the intensity of each training session or exactly how long individual sessions ran, both of which could influence outcomes considerably.
The exclusion of calisthenics and Pilates from the strength training category is a meaningful gap. Someone who does 90 minutes of Pilates weekly and nothing else would not register as a strength trainer in this dataset, regardless of the muscular demands those sessions place on the body. Future research that captures a broader definition of resistance-based exercise would produce a more complete picture.
Still, the core finding holds up as an association: people who consistently did 90 to 120 minutes of strength training per week over long periods had lower rates of death from cardiovascular and neurological causes, and from any cause, than those who did little or none.
Practical Implications of the 90–120 Minute Window
The study’s finding that benefits plateau after 120 minutes per week is arguably as useful as the 13% risk reduction itself. For anyone already training more than two hours weekly, there is no mortality data here to justify the extra time if longevity is the primary goal. For anyone not training at all, the ceiling is low enough that getting there is realistic — two 45-minute sessions, or three 30-minute sessions, lands squarely in the range.
Strength training’s established benefits outside of mortality data include improved bone density, better balance, and support for weight management. The cardiovascular and neurological risk reductions found in this study add to that existing picture rather than replacing it. Hougen described aerobic exercise — the kind that raises heart rate — as a necessary component of overall health, with strength training functioning as a distinct and important addition rather than a substitute.
For practical purposes, the study’s definition of strength training — free weights, machines, push-ups, squats, lunges — is accessible across a wide range of circumstances and fitness levels. Not all of those options require a gym membership or specialized equipment.
A 30-Year Window on a Two-Hour Habit
Few things in health research get tracked for three decades. The length of this study is part of what makes its associations worth taking seriously, even with all the caveats an observational design carries. Participants answered questions about their exercise habits roughly 15 times over the study period — that kind of longitudinal consistency captures habitual behavior in a way that short-term trials simply cannot.
The 35,798 deaths recorded over the study period provided a large outcome pool, making it possible to detect associations at the disease-specific level that smaller studies would miss entirely. The neurological disease finding — a 27% lower risk of death in the 90–120 minute group — is particularly notable given how little the general fitness conversation addresses neurological outcomes.
Whether 90 minutes of training achieved over two sessions produces the same effect as 90 minutes spread across six shorter sessions is a question this study doesn’t answer. Session duration and intensity data weren’t collected, leaving a gap that matters for people designing actual training schedules.
The upper boundary of the study’s benefit window sits at 120 minutes per week.
This article is for general informational purposes only and does not constitute personalized medical advice. Exercise recommendations, health risk figures, and study findings described here are drawn from a specific research publication and may not apply to every individual. Consult a qualified healthcare provider before making changes to your exercise routine. Study data and associated figures are as reported at the time of publication; always refer to the original source for the most current information.