Strength Training and Lifespan: 30 to 60 Minutes a Week

Popular lifting programmes are written for muscle and strength gains, and typically ask for several hour-long sessions a week. The cohort studies that track who lives longer describe something much smaller. When Momma and colleagues pooled 16 cohorts in 2022, the lowest mortality sat at roughly 30 to 60 minutes of muscle-strengthening activity a week, and the association did not keep improving with more. That is one or two short sessions.

The dose in the pooled data

The Momma meta-analysis (British Journal of Sports Medicine, 2022) is the widest lens. Across 16 cohort studies, muscle-strengthening activity was associated with 10 to 17 percent lower risk of all-cause mortality, cardiovascular disease, diabetes, total cancer and lung cancer. For mortality, cardiovascular disease and total cancer the dose-response curves were J-shaped: the largest risk reduction, roughly 10 to 20 percent, sat at about 30 to 60 minutes a week, and the authors describe the influence of higher volumes as unclear. Diabetes was the exception, with an L-shaped curve showing a large reduction up to 60 minutes a week.

Two other meta-analyses point the same way. Shailendra and colleagues (American Journal of Preventive Medicine, 2022) pooled ten studies and found any resistance training associated with 15 percent lower all-cause mortality (relative risk 0.85), 19 percent lower cardiovascular mortality (0.81, a confidence interval touching 1.00) and 14 percent lower cancer mortality (0.86). Their dose-response analysis put the largest reduction, 27 percent, at around 60 minutes a week. Saeidifard and colleagues (European Journal of Preventive Cardiology, 2019) pooled 11 studies and 370,256 people followed for a mean of 8.85 years: resistance training alone was associated with 21 percent lower all-cause mortality (hazard ratio 0.79), and combined with aerobic exercise with 40 percent lower (0.60).

Only one of Saeidifard’s 11 studies was a randomised trial; the rest of this literature is observational.

What the individual cohorts add

Strength work on its own counts. Stamatakis and colleagues (American Journal of Epidemiology, 2018) pooled 11 population cohorts: 80,306 adults aged 30 and over and 5,763 deaths. Any strength-promoting exercise was associated with 23 percent lower all-cause mortality (hazard ratio 0.77) and 31 percent lower cancer mortality (0.69). Meeting only the strength guideline (at least two sessions a week) gave a hazard ratio of 0.79 for all-cause mortality, only the aerobic guideline (150 minutes a week) 0.84, and both 0.71.

It stacks with cardio, but cardio carries more. In the PLCO cancer-screening cohort of 99,713 adults, mean age 71, followed for a median of nine years, Gorzelitz and colleagues (British Journal of Sports Medicine, 2022) found weightlifting was associated with a hazard ratio of 0.91 for all-cause mortality after adjustment for aerobic activity. In the joint model, people who met the aerobic guideline but did not lift had a hazard ratio of 0.68, and those who also lifted one to two times a week 0.59. Weightlifting was not associated with cancer mortality once aerobic activity was accounted for. The aerobic side is covered in the post on VO2 max and lifespan.

Once a week is where the extra benefit shows up. Coleman and colleagues (British Journal of Sports Medicine, 2022) linked 416,420 US survey respondents to death records. One hour a week of aerobic activity was associated with a hazard ratio of 0.85, and the curve levelled off at three hours (0.73). Muscle-strengthening exercise added a further reduction at once a week (0.89), but by seven times a week the estimate was 0.99, indistinguishable from no benefit.

Older adults rarely do it, and those who do fare better. Kraschnewski and colleagues (Preventive Medicine, 2016) analysed 30,162 US adults aged 65 and over in a 15-year cohort study. Only 9.6 percent reported strength training at least twice a week; those who did had an adjusted odds ratio of 0.64 for all-cause mortality, holding after adjustment for medical history and health behaviours.

Why the curve may bend back

The starkest high-volume pattern comes from Liu and colleagues (Medicine and Science in Sports and Exercise, 2019): 12,591 adults, mean age 47, with 205 cardiovascular events and 276 deaths over mean follow-ups of 5.4 and 10.5 years. Lifting once, twice or three times a week, or for under an hour in total, went with roughly 40 to 70 percent fewer cardiovascular events, independent of aerobic exercise. More than four sessions, or 60 minutes or more a week, showed no significant reduction. The pattern for all-cause mortality was similar, and a mediation analysis split the effect into a direct association with cardiovascular risk that was U-shaped and an indirect path through lower body mass index.

Unglamorous explanations should come before biological ones. The top categories in these surveys hold few people, so their confidence intervals are wide. Lifting time is self-reported, and a person logging seven sessions a week differs from one logging two in occupation, injury history, body weight and reasons for training. Momma’s J-shape and Coleman’s fade-out at seven sessions are consistent with a real plateau, but nothing here shows that lifting more is harmful; it shows that the mortality association stops improving.

Grip strength: the measurement behind the story

Part of the case rests not on training at all but on squeezing a dynamometer.

In the PURE study (Lancet, 2015), Leong and colleagues measured grip strength in 139,691 adults across 17 countries and followed them for a median of four years, during which 3,379 died. Each 5 kg lower grip was associated with 16 percent higher all-cause mortality (hazard ratio 1.16), 17 percent higher cardiovascular mortality, and smaller increases in heart attack (1.07) and stroke (1.09). Grip beat systolic blood pressure as a predictor of death from any cause and from cardiovascular disease.

UK Biobank repeated the exercise in 502,293 people aged 40 to 69 (Celis-Morales and colleagues, BMJ, 2018). Over a mean of 7.1 years and 13,322 deaths, each 5 kg lower grip carried hazard ratios of 1.20 for all-cause mortality in women and 1.16 in men, largest for respiratory mortality (1.31 and 1.24). Adding grip to an office-based risk score improved its discrimination only slightly (C-index gain 0.013), a caution against treating a dynamometer as a crystal ball.

García-Hermoso and colleagues (Archives of Physical Medicine and Rehabilitation, 2018) pooled 38 studies and 1.9 million apparently healthy people: high versus low handgrip strength was associated with a hazard ratio of 0.69 for all-cause mortality (0.60 in women, 0.69 in men), and high versus low knee-extension strength with 0.86.

None of this shows that training grip extends life. Grip is a cheap proxy for whole-body muscle and general condition, and a weak grip may reflect illness already under way. It does show that strength carries prognostic information blood pressure alone does not.

Strength is trainable at any age

The one place with genuine randomised evidence is not mortality but function. Fiatarone and colleagues (New England Journal of Medicine, 1994) randomised 100 frail nursing-home residents, mean age 87 and as old as 98, to ten weeks of high-intensity progressive resistance training, a nutritional supplement, both or neither. Muscle strength rose 113 percent in the exercise groups against 3 percent in the non-exercisers; gait velocity improved 11.8 percent against a 1 percent decline; stair-climbing power rose 28.4 percent against 3.6 percent. The supplement, taken without exercise, moved none of the primary outcomes.

That trial is small and short, but it makes a point the cohorts cannot: the strength deficit that predicts mortality is modifiable, even at the end of life. How much muscle grows from a given weekly dose is a separate question, covered in the post on what hypertrophy research shows; the mortality data track the activity, not visible muscle. For supplements alongside training, the post on creatine beyond the gym covers the trials in older adults.

What the evidence cannot say

No randomised trial has assigned people to years of strength training and counted deaths. Every mortality estimate above is an association from people who chose to lift, adjusted for whatever was measured. Confounding by overall health, income and other habits cannot be removed by adjustment; the question is how much of the 10 to 20 percent it explains.

The 30 to 60 minute figure describes where the pooled curve peaks, not a ceiling. It says nothing about the dose for muscle size, bone density, sport performance or rehabilitation. And the categories are coarse: “muscle-strengthening activity” spans gym weights, bands and calisthenics, and few studies separate them.

Anyone with a heart condition, uncontrolled blood pressure or an injury history should talk to a clinician before starting a resistance programme; the survival data say nothing about technique, load or progression.

Bottom line

Across three meta-analyses and several large cohorts, muscle-strengthening activity is associated with roughly 10 to 20 percent lower all-cause mortality, peaking at about 30 to 60 minutes a week, and it adds to rather than replaces the larger benefit linked to aerobic exercise. Very high volumes show no further gain, though nothing indicates harm. Grip-strength studies in close to two million people show strength predicts survival, in PURE better than systolic blood pressure. All of it is observational; the randomised trials show strength and function improving, not lifespan. One or two short sessions a week is the dose the survival data point to, far less than a muscle-building programme asks for.