Weight-lifting may reduce cardiovascular mortality risk but the dose-response relationship and the combined benefit with aerobics is unclear
Both aerobic physical activity and muscle-strengthening activities on 2 or more days a week such as weight-lifting, are recommended to provide substantial health benefits. In fact, there is good evidence that increased levels of physical activity via aerobic type activities, are associated with a lower mortality risk. However, far less is known about the all-cause and cardiovascular mortality benefits of strength training activities. One analysis of prospective studies found that participation in strength training activities (compared to none) was associated with 21% lower risk of all-cause mortality and a borderline association with lower cardiovascular mortality. Moreover, the authors also noted in the paper that there was lack of evidence on the dose-response relationship between muscle-strengthening activities and cardiovascular risk.
For the present study, a team of US researchers set out to examine the relationship between weight-lifting and all-cause, cardiovascular and cancer mortality both independently and when combined with aerobic moderate to vigorous physical activity (MVPA). They used data from the Prostate, Lung, Colorectal and Ovarian (PLCO) screening trial which began in 1993 and 13 years later, sent follow-up questionnaires to participants which asked about levels of weight-lifting as well as both moderate and vigorous physical activity. For the subsequent analysis of mortality data, the team adjusted for demographic and lifestyle factors which had been assessed in the follow-up questionnaire. In addition, researchers considered the mortality impact based on individual’s reported levels of aerobic MVPA, which was categorised as none, some, meets or exceeds.
Weight-lifting and cardiovascular mortality
A total of 99,713 individuals with a mean age at the start of the follow-up period of 71.3 years (52.6% female) were included in the analysis and followed over an average of 9.6 years. Overall, 23% of participants reported undertaking any weight-lifting activities.
Adults reporting any level of weight-lifting activity had a 9% lower risk of all-cause mortality (Hazard ratio, HR = 0.91, 95% CI 0.88 – 0.94) and for cardiovascular disease mortality (HR = 0.91, 95% CI 0.86 – 0.97) but the reduction in cancer mortality risk was non-significant. Without any adjustment for aerobic activity, lifting weights 1 – 2 times/week was independently associated with a 17% reduced risk of cardiovascular mortality (HR = 0.73, 95% CI 0.79 – 0.97). Interestingly however, increasing the weight-lifting frequency to between 3 and 7 or more times/week did not further reduce the risk of cardiovascular mortality (HR = 0.76, 95% CI 0.71 – 0.82).
When researchers examined all-cause mortality based on the different MVPA categories, those undertaking weight-lifting 1 – 2 times/week and who met MVPA requirement, had 41% lower all-cause mortality (HR = 0.59, 95% CI 0.54 – 0.64). As before, among those who ‘met’ the MVPA requirements, higher levels of weight-lifting activity, did not further reduce all-cause mortality (HR = 0.61).
The authors concluded that both weight-lifting and aerobic activity were independently associated with a reduced all-cause and cardiovascular disease mortality risk and support the notion that both activities were associated with longevity in older adults.
Gorzelitz J et al. Independent and joint associations of weightlifting and aerobic activity with all-cause, cardiovascular disease and cancer mortality in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial Br J Sports Med 2022