Physical activity and sex differences: is the cardiovascular benefit the same?

We know that men have greater exercise capacity than women, which is certainly secondary to anatomical and physiological aspects. Despite the guidelines recommending the same amount of exercise for both men and women, there is still a gap in understanding the amount of exercise related to health benefits in men and women.

Sex differences in physical activity and association with all-cause and cardiovascular (CV) mortality have been recently described in a prospective study published on JACC (Journal of American College of Cardiology) by H. Ji et al.¹

The authors investigated if sex-specific multivariable-adjusted associations of frequency, duration, intensity, and type of physical activity are all associated with all-cause and CV mortality in 412.413 adults (55% being females, with age 44±17 years), over 22 years. Sociodemographic characteristics, ethnicity, medical comorbidities, and self-related health status were also collected at each survey.

The results show, not surprisingly, a clear benefit of physical activity (considered as >150 min/week of moderate to vigorous-intensity aerobic physical activity) in reducing all-cause mortality in both men and women compared to physically inactive men and women (<150 min/week of moderate to vigorous-intensity aerobic physical activity) (HR 0.76; 95% CI:0.73-0.80). However, very interestingly, the authors show that aerobic physical activity benefit for all-cause mortality is lower in men compared to women (15% lower risk in active men vs inactive and 24% lower risk in active women compared to inactive). Indeed, it has been already previously described that sex can modify the relationship between fitness and mortality.²

Remarkably, the study from H.Ji et al.¹  describes how the peak benefit for all-cause mortality, regarding moderate to vigorous physical activity, stands at 300 min/week in men and at 140min/week in women. While in men a plateau was observed at 110 minutes per week (18% lower hazard in all-cause mortality reduction), in women the benefit continued to increase up to a peak benefit at 300 min/week (24% lower hazard in all-cause mortality reduction). Similar results are shown for CV mortality with a statistically significant sex difference, showing that the benefit of regular aerobic physical activity compared to inactivity is greater in women than in men. These health benefits for aerobic physical activity were consistent, considering duration per session, frequency, and intensity, with higher survival benefits in women compared to men.

Regarding regular muscle strength activity, it was more frequent in men compared to women (28% of men compared to 20% of women), but the benefit seems greater for women (all-cause mortality risk reduction of 19% in women compared to 11% in men and CV mortality benefit of 30% in women compared to 11% in men).

Of notice, in the secondary analyses, the degree of physical activity mortality risk reduction was greater in women than men particularly for middle aged individuals (between 40 and 59 years old), with attenuation if age was <40 years old or ≥60 years old.

Additionally, a positive relationship was seen between both aerobic physical activity and muscle strengthening, with perceived quality of life and this did not differ between the two sexes. Equally the physical activity engagement was associated with lower odds of diabetes in both sexes.

In summary, the authors reported data from a cohort of adults followed over >4 million person-year proving that women may gain a greater benefit compared to men in term of all-cause mortality and CV mortality from equivalent exercise dose.

Despite all data being self-reported and objective measures difficult to ascertain, the results presented in this study could influence sex specific exercise recommendations in future international guidelines, guiding sex specific physical activity and improving cardiovascular prevention.

This study offers valuable insights to narrow the “gender gap” on CV equity, with 3 key messages:

1. Equivalent doses of aerobic physical activity and muscle strengthening have greater benefit for all-cause and CV mortality in women compared to men.

2. Encourage physically inactive women to engage more in sport and avoid a sedentary lifestyle.

3. Continue to motivate already physically active women to reach benefits for all-cause and CV death (all types of leisure-time physical activity).