Study examines lifting and lifespan
A new study published this month in the British Journal of Sports Medicine looked at how much resistance exercise may be linked to a longer and healthier life.
Researchers analyzed 30 years of data from more than 147,000 men and women, comparing weekly time spent lifting weights with the risk of premature death.
Even small amounts appear beneficial
The study found that any amount of resistance training, even just a few minutes per week, was associated with a lower risk of dying early compared with doing no weight training at all.
This association was seen even among people who already did aerobic activities such as walking, running or other forms of cardio exercise.
Strongest links seen for heart and brain health
The benefits appeared especially notable for cardiovascular disease and neurological conditions. People who lifted weights, even infrequently, were less likely to die from heart attacks or Alzheimer’s disease than those who did no resistance exercise.
The researchers also searched for a “Goldilocks” amount of lifting, meaning the weekly range that seemed neither too low nor excessive, but most strongly linked with longevity.
Less is known about lifting than cardio
Scientists have studied aerobic exercise and longevity for decades. Current Department of Health and Human Services recommendations call for at least 150 minutes per week of moderate activity, such as brisk walking.
Recent studies have also linked smaller amounts of aerobic activity with better health and longer life, particularly when the effort is intense.
“But less is known about how resistance exercise relates to long-term mortality risks,” said Edward Giovannucci, a professor of nutrition and epidemiology at the Harvard T.H. Chan School of Public Health and senior author of the study, “especially at different amounts and combinations with aerobic activity.”
HHS guidelines recommend two days per week of muscle-strengthening exercise, but they do not specify much beyond that.
Nearly 150,000 participants studied
Giovannucci and his colleagues used long-running Harvard health databases that have tracked nurses and other health care workers for about 30 years.
Participants repeatedly completed detailed questionnaires about their exercise habits, including time spent running, walking, cycling, swimming or doing other aerobic activities. They also reported how often they lifted weights, especially using free weights and weight machines.
The researchers reviewed data from 147,374 men and women, most of whom were middle-aged when they entered the studies. They then compared exercise patterns with death records over roughly the next 30 years.
The optimal range was 90 to 119 minutes
The clearest longevity sweet spot for resistance training was between 90 and 119 minutes per week.
People who lifted for that amount of time had a 13% lower risk of premature death from any cause and a 19% lower risk of dying from heart disease.
The strongest association was seen for neurological diseases such as dementia. In that category, the risk of death was 27% lower.
More lifting did not add extra benefit
Smaller amounts of resistance exercise were also linked with longer life, although the reduction in risk was more modest.
After 119 minutes per week, the benefits appeared to level off. Lifting more did not increase mortality risk, but it also did not seem to provide additional longevity gains.
Combining cardio and lifting worked best
The benefits linked to resistance training appeared to be separate from those associated with aerobic exercise. The researchers controlled for cardio activity, meaning the gains from lifting seemed to add to the benefits of aerobic workouts.
“People who combined aerobic exercise with resistance training generally had the lowest mortality risk,” said Yiwen Zhang, a postdoctoral research fellow at the Harvard T.H. Chan School of Public Health who led the study.
David Scott, an exercise scientist at Deakin University in Australia who was not involved in the research, said the findings were strong.
“Given its large sample size and long-term follow-up period, with repeated measures of resistance-training behaviors, the findings are convincing,” Scott said.
Questions remain about workout structure
The study did not determine the best way to divide 90 to 119 minutes of lifting across the week. It remains unclear whether three 30-minute sessions, 15 minutes per day or one longer workout would produce different longevity results.
The research also did not answer whether heavy weights are better than lighter weights, or whether calisthenics such as push-ups could be as effective as machine-based exercises.
“Future research is certainly needed” to answer those questions, Giovannucci said.
Why strength training may protect health
The study does not prove exactly why resistance exercise is linked with lower mortality risk. Other research suggests that strength helps preserve mobility, reduces fall risk with age and supports long-term metabolic health.
Resistance training may also benefit the brain by releasing substances into the bloodstream that travel to the brain and activate processes associated with healthier aging.
Researchers apply the findings personally
The results have reinforced the habits of the study’s authors. Giovannucci said he has lifted weights for decades.
“I’ve been doing so for the past 25 years,” Giovannucci said, “typically two to three times a week, about 45 minutes each time.”
Zhang said she currently lifts lightly about twice a week, for roughly one hour total. After reviewing the findings, she said, “I’m aiming to build up.”
