Analysis of 80,000 adults finds women get stronger heart benefits from shorter workouts.
Men may need to exercise for nearly twice as long as women to gain the same protection against heart disease, according to new research suggesting that physical activity guidelines should account for biological sex differences.
Scientists analysed exercise and health data from more than 80,000 adults and found that women who worked out for around four hours a week reduced their risk of coronary heart disease by 30%. Men needed to exercise for about nine hours a week to achieve the same benefit.
The study, published in Nature Cardiovascular Research, builds on previous findings that women tend to gain greater cardiovascular benefits than men from equivalent levels of exercise, even though they are typically less active and less likely to meet recommended activity targets.
Under current NHS guidelines, adults are advised to take at least 150 minutes of moderate exercise or 75 minutes of vigorous activity each week, along with strength training twice a week. The new findings suggest that these recommendations may need to be more tailored to reflect sex-specific effects on heart health.
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“Compared with male individuals, females derive equivalent health benefits with only half the exercise time,” the authors wrote. “The findings might encourage females to engage in physical activity.”
The research team, led by Dr Jiajin Chen at Xiamen University in China, used data from fitness trackers worn by volunteers enrolled in the UK Biobank project — a long-term study that follows the health of more than half a million people in the UK.
They examined 80,243 participants without existing coronary heart disease at the start of the study. Among this group, women who met the weekly exercise target had a 22% lower risk of developing heart disease over an eight-year follow-up period, compared with a 17% lower risk for men who met the same target.
When researchers looked at higher activity levels, they found that women who exercised for 250 minutes a week reduced their risk by 30%. Men needed 530 minutes a week — almost nine hours — to achieve a similar reduction.
The most striking results came from an analysis of more than 5,000 participants who already had coronary heart disease. In this group, physically active women were three times less likely to die during the follow-up period than men who exercised the same amount.
Professor Yan Wang, a senior author of the study, said the findings underline that both sexes can gain “substantial cardiovascular benefits” from regular physical activity, but women appear to respond more efficiently to the same level of exercise.
“Globally, more women than men fail to meet physical activity targets,” he said. “We particularly hope our findings encourage physically inactive females to become more active, thereby reducing their cardiovascular risk.”
The reasons behind the difference remain unclear. Scientists believe it could be related to variations in sex hormones, muscle composition and metabolism, including how the body converts sugar into energy during exertion.
In a commentary accompanying the study, Dr Emily Lau, a cardiologist specialising in women’s heart health at Massachusetts General Hospital, said the findings challenge the notion that the same exercise prescription should apply equally to both sexes.
“This study provides further evidence that one size really does not fit all,” she wrote. “It is time to embed sex-specific strategies into public health guidelines and to develop tailored interventions to optimise cardiovascular health for women.”