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- A new study found that 90-120 minutes of weekly strength training was linked to the greatest longevity benefits.
- Two hours a week may be enough to build muscle, maintain bone density, and support mobility without the risks of excessive training.
- Experts say combining strength training with regular cardio may offer the strongest protection for long-term health.
You don’t need to spend hours at the gym every week to improve your longevity. A new study published in the British Journal of Sports Medicine found that 90–120 minutes of weekly strength training may be the sweet spot for lowering your risk of death.
What the Study Found
Researchers examined data from nearly 150,000 participants across three major health studies. Every two years, participants reported the average weekly time they spent doing resistance training (including workouts with machines or free weights) and aerobic exercise (such as walking, cycling, and swimming).
During the 30 years of follow-up, researchers found that greater amounts of strength training were associated with a lower risk of death. However, the benefits leveled off at about 120 minutes per week.
More specifically, 90–119 minutes of weekly resistance training was associated with a 13% lower risk of death from any cause, a 19% lower risk of dying from a cardiovascular condition, and 27% lower risk of dying from a brain-related condition, compared to doing no strength training.
While overall mortality benefits peaked at about 90–120 minutes per week, cancer mortality followed a different pattern: Participants who did 30–59 minutes of strength training weekly had a 12% lower risk of dying from cancer, compared to those who did none.
“This suggests that different amounts of resistance training may be optimal for different health outcomes,” said Edward Giovannucci, MD, ScD, a professor of nutrition and epidemiology at Harvard T.H. Chan School of Public Health and an author of the new study.
Researchers also compared different exercise patterns. People who met aerobic exercise recommendations (at least 150 minutes per week) without strength training had a 26% to 43% lower mortality risk.
But the greatest benefit was seen among those who combined aerobic exercise and resistance training: People who hit the ideal amount of both each week had a 45% lower risk of death.
However, the research had several limitations. Participants self-reported their physical activity, presenting the risk of bias. The study excluded certain types of strength training, such as calisthenics and Pilates, and did not consider the duration or intensity of workouts.
Because of these shortcomings, 90–120 minutes should not be interpreted as a strict threshold, said Yiwen Zhang, PhD, a postdoctoral research fellow at Harvard T.H. Chan School of Public Health and an author of the new study.
Rocky Snyder, CSCS, author of the strength training guide Return to Center, who was not affiliated with the research, said the study results are still encouraging.
“You don’t need extreme exercise volumes to substantially improve long-term health outcomes,” he told Health. “Consistent, intelligent movement performed for decades is probably more important than chasing maximal training volume.”
Why Might 2 Hours of Weekly Strength Training Be Ideal?
Research suggests that about two hours of weekly resistance training is enough to help build muscle, maintain bone density, and improve mobility—all of which support healthy aging.
The new study did not examine why mortality benefits appeared to plateau around that amount of exercise, but higher training volumes may lead to chronic inflammation, fatigue, sleep disruption, and stress on bones and joints, especially in older adults, Snyder said.
Plus, two hours of strength training each week is a realistic goal for most people, Snyder said, allowing them to sustain a workout routine for years.
“Sustainability matters enormously for longevity,” he added. “A program somebody can follow consistently for 20 years is more valuable than an extreme program they abandon after six months.”
The study found that aerobic exercise was associated with a lower mortality risk than strength training alone, which the authors said may reflect its strong impact on cardiovascular and metabolic health.
However, “with minimal rest and proper pacing, strength training can elevate and maintain heart rate levels in a way that can replicate some cardiovascular training benefits,” Gideon Akande, NASM-CPT, a certified personal trainer and BowFlex fitness advisor, told Health.
How to Exercise for Longevity
Experts recommend incorporating both strength training and aerobic exercise into your fitness routine for the best longevity benefits.
“For people who already do aerobic activity, adding even some resistance training may provide additional benefit,” Giovannucci said.
Susie Reiner, PhD, assistant professor of exercise and sport science at Seton Hall University and founder of TheoryEx, suggested doing two to three days of full-body strength training a week, totaling 90–120 minutes, and getting at least 150 minutes of moderate-intensity aerobic exercise, such as cycling, swimming, or brisk walking.
Ultimately, experts agreed that consistency matters more than pursuing a perfect fitness routine.
“The best combination of exercise,” Reiner said, “is the one you will consistently do for years with gradual progression over time.”
