Can an hour of strength training a week really make you stronger?

Yahoo

01-05-2025

Various studies found weight training to be beneficial for body and mind, including one that suggests it might help protect the brains of older adults from dementia.
But just how often should you lift?
According to a new study, the answer is about an hour a week.
During the two-month study, 42 healthy men and women gained significant muscle mass and strength from two 30-minute sessions of uncomplicated resistance exercises each week, per the Washington Post. The research was published in the journal Medicine & Science in Sports & Exercise.
In each session, participants did nine common upper- and lower-body gym exercises, repeating each move eight to 10 times, until their muscles felt fatigued but not necessarily exhausted.
The routine was meant to be short because so many people blame busy schedules for not lifting, Brad Schoenfeld, a professor of exercise science at Lehman College in the Bronx and the study's senior author, told the Post.
'We were interested in finding the minimum effective dose' of resistance training for most people, he said.
The Centers for Disease Control and Prevention estimates that only about 20% of American adults strength train even a few times a week.
The new study is the latest one to find strength training in short durations has long-term health benefits.
A 2022 meta-analysis published in the British Journal of Sports Medicine found that people who do muscle-strengthening workouts are less likely to die prematurely than those who don't.
According to the study, those who did 30 to 60 minutes a week of strength training had a 10% to 20% lower risk of dying during the research period from all causes, including cancer and heart disease specifically, compared to those who did no weight lifting. The benefits plateaued after one hour, and decreased after two hours.
U.S. exercise guidelines recommend that adults do strength training for all major muscle groups twice a week, which can be accomplished with a variety of workouts, including weightlifting, exercises like push-ups and sit-ups, and some types of yoga.
The current guidelines don't specify how long strength workouts should be, but more research is needed before revising the guidelines to include time-specific goals, said I-Min Lee, professor of epidemiology at Harvard T.H. Chan School of Public Health.
Lee, who was not involved in the study, said that two 30-minute strength workouts per week would fit the guidelines if all major muscle groups were targeted.
Muscle-strengthening exercises are beneficial because they lead to better physical functioning, she said.
'Such exercises also improve glucose metabolism, enhance maintenance of healthy body weight, and help improve cardiovascular risk factors such as blood pressure,' said Lee, per a Harvard T.H. Chan School of Public Health article. 'All these factors lead to lower risks of cardiovascular disease, cancer and diabetes, which lowers mortality risk.'
A 2025 study published in the journal GeroScience suggests that weight training might help protect the brains of older adults from dementia, including those already showing signs of mild cognitive impairment.
Researchers recruited 44 adults ages 55 or older with a diagnosis of mild cognitive impairment for the study. Participants were divided into two groups. The weight training group did a resistance exercise program with moderate to high intensity sessions twice a week, with progressive loads, meaning weight or sets were increased as participants' muscles strengthened. The control group did not exercise during the study period, per Medical News Today.
The study found that after six months, the weight training group showed improvement in verbal episodic memory and the strength of neurons and areas of the brain associated with Alzheimer's disease. The control group showed signs of worsening brain parameters.
'This is an interesting finding because it suggests that weight training may not only help to increase cognition, but also prevent the development of atrophy in regions related to Alzheimer's disease — potentially delaying progression or even preventing the onset of dementia,' Isadora Ribeiro, a São Paulo Research Foundation doctoral fellowship recipient at the School of Medical Sciences at the State University of Campinas in Brazil, told Medical News Today. Ribeiro is the study's first author.
In the study cited by the Washington Post, researchers invited their volunteers to the gym twice a week, for supervised sessions, where everyone did the same nine exercises:
Front lat pull-down
Seated cable row
Shoulder press
Chest press
Cable triceps pushdown
Supinated dumbbell biceps curl
Smith machine squats
Leg press
Leg extension
The participants completed only one set of each exercise, which, for many, was a substantial reduction in volume. Most had been doing at least two or three sets of every exercise during their workouts, spending hours in the gym every week. Now they finished in 30 minutes, per the Post.