Men must exercise nearly twice as long as women to achieve the same 30 per cent reduction in heart disease risk, according to new research.
Women who exercised for 250 minutes a week saw their coronary heart disease risk fall by 30 per cent, while men needed about 530 minutes — nearly nine hours — to achieve the same benefit.
The findings suggest that health guidelines may need to reflect sex-based differences in how the body responds to physical activity.
The study analysed physical activity data from more than 80,000 middle-aged volunteers who wore activity trackers as part of the UK Biobank project.
Led by Dr Jiajin Chen and colleagues at Xiamen University in China, the researchers tracked participants for eight years to assess cardiovascular outcomes.
Among 80,243 people without existing heart disease, women who met the NHS-recommended 150 minutes of weekly exercise had a 22 per cent lower risk of developing coronary heart disease compared with inactive women.
Men who met the same target saw only a 17 per cent reduction.
The most striking result came from more than 5,000 participants with existing coronary heart disease.
Women who met weekly exercise targets had a threefold lower risk of dying during follow-up compared with similarly active men.
Current NHS guidelines recommend that adults aged 16 to 64 complete at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise each week, plus muscle-strengthening activities on two days.
These recommendations do not distinguish between sexes.
Professor Yan Wang, a senior author on the paper, said that both sexes could gain “substantial cardiovascular benefits” from physical activity and emphasised that everyone should exercise regularly, regardless of sex.
“We particularly hope that our findings could encourage physically inactive females to become more active, thereby reducing their cardiovascular risk,” he said.
It remains unclear why exercise appears to benefit women more than men, but possible factors include differences in sex hormones, muscle fibre composition and how efficiently the body metabolises sugar to produce energy.
Women typically have more type I muscle fibres, which are better suited to endurance and fat metabolism.
Globally, more women than men fail to meet recommended physical activity targets, despite potentially gaining greater cardiovascular benefits from smaller amounts of exercise.
One in three women worldwide die from cardiovascular disease.
In an accompanying article, Dr Emily Lau, a women’s cardiovascular health specialist at Massachusetts General Hospital, wrote: “This study provides further evidence that one size really does not fit all and challenges us to move from conversation to action.
“It is time to embed sex-specific strategies into guidelines and to develop tailored interventions to optimise cardiovascular health for women.”
The findings build on earlier research suggesting that women gain greater cardiovascular benefits than men from the same amount of exercise, even though they are typically less active and less likely to meet recommended targets.