Women generally exercise less than men do, but new research suggests they see greater health benefits from it. 

A national study found that women who exercised regularly — at least 2½ hours of moderate exercise or 75 minutes of vigorous exercise per week — had a 24% lower risk of dying over the study period compared with women who didn’t exercise. By contrast, men who exercised regularly were 15% less likely to die than men who didn’t exercise. 

Men also needed more exercise than women to achieve the same health benefits: Five hours of moderate or vigorous exercise per week reduced their risk of dying by 18% compared with men who didn’t exercise. But just 140 minutes of weekly exercise had the same effect among women.

“Women got the same benefit at lower levels of physical activity,” said a co-author of the study, Dr. Martha Gulati, the director of preventive cardiology at Cedars-Sinai’s Smidt Heart Institute in Los Angeles. 

Women who exercised regularly also had a 36% lower risk of dying from a cardiovascular issue such as a heart attack or stroke, the study found, whereas men who exercised regularly had a 14% lower risk. 

The findings were published Monday in the Journal of the American College of Cardiology. The researchers analyzed the self-reported exercise habits of more than 412,000 men and women who participated in the National Health Interview Survey over from 1997 to 2017. 

Roughly one-third of the women regularly engaged in aerobic exercises — ones that elevate the heart rate, such as brisk walking, jumping rope or taking spin classes — compared with 43% of men in the study. Women were also less likely than men to do muscle-strengthening activities, such as lifting weights. 

Nevertheless, regular muscle strengthening — roughly one session per week, on average — was associated with a 30% lower risk of women dying from cardiovascular problems and a 19% lower risk of dying overall. Among men, the same weekly exercises lowered the risk of dying from cardiovascular problems by 11% and of death by the same percentage.

Gulati said one major limitation of the study is that it didn’t account for how active women were outside workout settings.  

“Missing from our data are the things that we do every day — the other physical activity that’s not going to the gym but running after kids, doing gardening, doing household chores,” she said.

Should men and woman have different exercise recommendations?

The Department of Health and Human Services recommends that adults get 150 minutes of moderate physical activity per week, including two days of muscle-strengthening activities. 

But Gulati said those guidelines “can be very overwhelming to someone who does zero.” Many of her female patients struggle to find time for exercise, she said. 

“Women are busy. Women work. Women usually take the bulk of family responsibilities — whether that’s children, whether that’s elderly parents — and by the time the day finishes, there’s very little time,” Gulati said.

Data from the National Health Interview Survey suggests that women in 2022 were more likely than men to have been advised over the past year by doctors or other health professionals to increase their amounts of physical activity. 

“Rather than talking about 150 minutes a week, the way that we should be saying it is: What can you fit in?” Gulati said.

Paul Arciero, a professor of sports, medicine and nutrition at the University of Pittsburgh, said it’s only logical to have separate exercise guidelines for men and women.

“There are clear, sex-based differences in response to exercise,” he said. “We have to move beyond thinking that men and women respond similarly.”

What’s causing the sex-based difference?

Many studies have shown that exercise doesn’t affect men and women in the same way.

Arciero’s research in 2022 found that women had greater reductions in blood pressure when they exercised in the morning, whereas men had greater reductions at night. A 2020 review also found that women’s muscles are more resistant to fatigue from high-intensity exercise.

But scientists have been less certain about how those differences affect people’s long-term health. 

The new study shows that “women are basically more efficient in responding to exercise, particularly when it comes to heart health and mortality,” said Arciero, who wasn’t involved in the paper.

Arciero said physiological differences may contribute to the advantage: Women have more capillaries (tiny blood vessels) in a given section of muscle than men do, which could allow more blood and oxygen to flow to the heart during exercise. 

Women also have higher levels of the hormone estrogen, which enhances blood flow, said Lynda Ransdell, the chair of the kinesiology department at Boise State University.

Ransdell pointed to a third factor as, well: Women tend to be less physically active, so it may take less effort to improve their health relative to their baselines.

“I would call it the principle of diminishing returns,” Ransdell said. “Since women typically start at lower levels of fitness, they can see significant gains with taking up a little less physical activity.”

But scientists have more to learn, she added.

“While I love this study and I think it’s groundbreaking and landmark, I also believe that it’s one piece of a puzzle,” Ransdell said. “I would love to see them do more research with objective measures of physical activity like pedometers or Apple watches.”