Women need to exercise only half as much as men to reap the same longevity benefits, suggests a recent study – with the researchers saying their findings offer clear proof that “women are not just small men”.
The paper, published in the Journal of the American College of Cardiology, is also encouraging for women who struggle to motivate themselves to hit the gym, said co-author Dr Martha Gulati, director of preventive cardiology at Cedars-Sinai in Los Angeles.
“For me, the news to women is: a little goes a long way,” she said.
In the study, men who did about 300 minutes of aerobic exercise every week had an 18% lower risk of dying compared with inactive men, the researchers found. But among women, it took only 140 minutes of weekly exercise to see an equivalent benefit – and the risk of death was 24% lower among those who got about 300 minutes of movement per week. (For both sexes, longevity benefits seemed to plateau beyond 300 minutes of weekly exercise.)
TIME reports that the researchers ran a similar analysis on muscle-strengthening exercise, like weight training. They found the same pattern: for women, a single weekly strength-training session was associated with just as much longevity benefit as three weekly workouts for men.
“Women tend to have less muscle mass than men,” Gulati said, “so if they do the same amount of strengthening exercises, they may have greater benefits with smaller doses just based on the fact that they don’t have as much to begin with.”
Other sex-based physiological differences, like differences in the lungs and cardiopulmonary system, may also come into play.
To reach their findings, Gulati and her colleagues analysed self-reported exercise habits from more than 400 000 US adults who took the National Health Interview Survey from 1997 to 2017, then compared those data with death records.
About 40 000 of the participants died during the study period.
That observational approach – meaning the researchers looked for patterns in pre-existing data – can’t prove cause and effect. It’s possible that exercise didn’t cause people to live longer, but rather that active people in the study were healthier overall or had other lifestyle habits that boosted longevity.
The researchers tried to control for those possibilities by excluding people who had serious pre-existing conditions or mobility constraints, or who died in the first two years of study follow-up, and thus may have been unhealthy from the beginning.
The study was also limited by its reliance on self-reported exercise data, which are not always accurate. The survey also asked about exercise people did in their free time, and thus may not have accounted for physical activity that occurred at work or during household chores – a type of movement that research increasingly suggests can meaningfully improve health.
In part because of those limitations, Gulati believes more research is required to confirm the findings. But, she said, the study, and others that have reached similar conclusions, offers a clear signal that “women are not just small men” and that sex-based differences must be incorporated into research and public-health policy.
“For years, we’ve used men as the standard,” she added, even when it may not have been accurate to do so.
Take the federal guidelines for physical activity, which issue the same blanket recommendation for US adults: at least 150 minutes of moderate aerobic exercise (or 75 minutes of vigorous cardio) and two muscle-strengthening sessions each week. In 2020, about 28% of American men hit both benchmarks, compared with 20% of women.
Gulati’s research, at least, suggests women may see significant longevity benefits even if they don’t quite meet those targets. But she says the study shouldn’t be discouraging for men, either.
The latest research suggests people of both sexes benefit from even very short chunks of activity, as just a few minutes of movement per day can boost longevity.
“Our pitch should be the same to men and women: something is better than nothing,” she said. “Sit less and move more.”
Study details
Sex differences in association of physical activity with all-cause and cardiovascular mortality
Hongwei Ji, Martha Gulati, Tzu Yu Huang, Alan Kwan, David Ouyang , Joseph Ebinger, Kaitlin Casaletto, Kerrie Moreau, Hicham Skali, Susan Cheng.
Published in Journal of the American College of Cardiology on 27 February 2024
Abstract
Background
Although physical activity is widely recommended for reducing cardiovascular and all-cause mortality risks, female individuals consistently lag behind male individuals in exercise engagement.
Objectives
The goal of this study was to evaluate whether physical activity derived health benefits may differ by sex.
Methods
In a prospective study of 412 413 US adults (55% female, age 44 ± 17 years) who provided survey data on leisure-time physical activity, we examined sex-specific multivariable-adjusted associations of physical activity measures (frequency, duration, intensity, type) with all-cause and cardiovascular mortality from 1997 to 2019.
Results
During 4 911 178 person-years of follow-up, there were 39,935 all-cause deaths including 11,670 cardiovascular deaths. Regular leisure-time physical activity compared with inactivity was associated with 24% (HR: 0.76; 95% CI: 0.73-0.80) and 15% (HR: 0.85; 95% CI: 0.82-0.89) lower risk of all-cause mortality in women and men, respectively (Wald F = 12.0, sex interaction P < 0.001). Men reached their maximal survival benefit of HR 0.81 from 300 min/wk of moderate-to-vigorous physical activity, whereas women achieved similar benefit at 140 min/wk and then continued to reach a maximum survival benefit of HR 0.76 also at ∼300 min/wk. Sex-specific findings were similar for cardiovascular death (Wald F = 20.1, sex interaction P < 0.001) and consistent across all measures of aerobic activity as well as muscle strengthening activity (Wald F = 6.7, sex interaction P = 0.009).
Conclusions
Women compared with men derived greater gains in all-cause and cardiovascular mortality risk reduction from equivalent doses of leisure-time physical activity. These findings could enhance efforts to close the “gender gap” by motivating especially women to engage in any regular leisure-time physical activity.
TIME article – To Live Longer, Women Need Half as Much Exercise as Men (Open access)
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