Association between physical activity and premature mortality: Differences between women and men?

Public health agency recommendations for the amount and frequency of physical activity apply to all adults, with no distinction between women and men. It is recommended that adults do at least 150 minutes per week of moderate-intensity aerobic physical activity or 75 minutes per week of vigorous-intensity aerobic physical activity. In addition, adults are encouraged to do 300 minutes of moderate-intensity exercise per week during leisure time if they want to further reduce the risk of developing cardiovascular disease. Despite these recommendations, fewer women than men exercise. This gender gap begins in childhood and continues into adulthood.

Although research focusing on gender differences in cardiovascular disease has made progress over the past 20 years, this disease remains the second leading cause of death after cancer in Canada and the leading cause in the United States. Recently, researchers have questioned whether the health benefits of physical activity are equal for men and women. Using data from a 22-year prospective study of 412,413 American adults, researchers examined the associations between physical activity (frequency, duration, intensity, type) and all-cause and cardiovascular mortality. Overall, 32.5% of women and 43.1% of men engaged in regular aerobic physical activity and all measures of this physical activity were significantly more frequent in men. Regular participation in physical activities of moderate intensity (≥150 min/week) was 15.2% for men and 10.3% for women, and regular participation in physical activities of vigorous intensity (≥ 75 min/week) was 38.9% for men and 28.3% for women.

All-cause mortality
Regular leisure-time physical activity, compared to inactivity, was associated with an all-cause mortality risk reduction of 24% for women and 15% for men. Men achieved maximum protection (18% risk reduction) by doing 300 minutes per week of moderate-to-vigorous intensity physical activity, while women achieved similar protection by doing 140 minutes per week of physical activity, and maximum protection (24%) at ~300 minutes per week (Figure 1).

Figure 1. Gender differences in all-cause mortality risk reduction associated with moderate-to-vigorous intensity physical activity. Adapted from Ji et al., 2024.

Muscle-strengthening exercises were performed regularly by 28% of men and 20% of women. The risk of all-cause mortality was reduced by 11% for men and 19% for women who did muscle-strengthening activities, compared to those who did not. Men who participated in 3 weight training sessions per week obtained the maximum mortality benefit (14% all-cause mortality risk reduction), while women obtained this same level of protection by doing only one weight training session per week.

Cardiovascular mortality
Similar associations between physical activity and cardiovascular mortality were observed. Indeed, regular leisure-time physical activity, compared to inactivity, was associated with a cardiovascular mortality risk reduction of 36% for women and 14% for men. Regularly doing muscle-strengthening activities, compared to inactivity, was associated with a cardiovascular mortality risk reduction of 30% for women and 11% for men. These male-female differences were highly significant (p < 0.001) according to statistical evaluations. The main results of the study are illustrated in Figure 2 below.

Figure 2. Gender differences in mortality risk reduction associated with physical activity. From Ji et al., 2024.

Limitations of the study
The authors identified several limitations to their study. First, data was collected using questionnaires, a less reliable method for estimating the quantity and frequency of physical activity than using accelerometers or smartwatches. In this study, leisure-time physical activity was considered; however, it is possible that other types of physical activity that were not measured could have contributed to the observed gender differences. Muscle-strengthening activities were estimated using data on the frequency of such activities, not their duration. The authors note that the observational nature of the study does not allow a causal link to be established and that the results should be interpreted with caution. Despite the precautions taken by the researchers to mitigate the effects of possible confounding factors and reduce the likelihood of a reverse causality effect, it remains possible that these phenomena had an influence on the data analyses.

The authors mention that several factors, including anatomical and physiological variations, could explain the differences in outcomes between men and women. For example, compared to men, women might use more of their respiratory, metabolic, and muscular strength resources to perform the same movement and, therefore, experience greater health benefits. The authors conclude by saying that the results of their study could be useful for physical activity assessment and recommendations, giving more consideration to the differences between women and men. More specific recommendations, i.e., those that take gender into account, could be more beneficial for everyone’s health, according to the authors.

We believe that although the results of this study are of interest, there are many methodological limitations, and it would be ill-advised to recommend that women exercise less than men based on this study alone. Further studies, using more reliable and efficient methodology and technologies, will be necessary to establish more precisely and with a higher degree of confidence what levels of physical activity are optimal for women’s health.