Between 30 and 60 minutes of muscle-strengthening activity every week is linked to a lower risk of death from all causes as well as a reduction in the risk of developing cardiovascular disease, diabetes, and cancer, a meta-analysis finds.
Physical activity guidelines already recommend regular muscle-strengthening activities (such as lifting weights and working with resistance bands, push-ups and squats and heavy gardening, including digging and shovelling), largely for musculoskeletal benefit.
Previous studies had shown muscle-strengthening activities were associated with a decreased risk of all-cause mortality and kidney cancer, but the dose-response association was unknown, researchers wrote in the British Journal of Sports Medicine.
To answer the question about the optimal dose, they conducted a systematic review of relevant prospective observational studies, finding 29 potentially eligible studies, of which 16 were included in the meta-analysis.
The studies were published between 2012 to 2020 with the majority conducted in the US, and others from England and Scotland, Australia, and Japan.
The pooled data analysis found muscle-strengthening activities were associated with a 10-17% lower risk of CVD, total cancer, diabetes, lung cancer and all-cause mortality, independent of aerobic activity.
For all-cause mortality, CVD and total cancer, researchers saw a J-shaped association with the maximum risk reduction obtained at approximately 30-60 min/week of muscle-strengthening activities.
Researchers saw an L-shaped association for diabetes, with the risk of the condition sharply decreasing until 60 min/week of muscle-strengthening activities, followed by a gradual decrease.
‘The influence of a higher volume of muscle-strengthening activities on all-cause mortality, CVD and total cancer is unclear when considering the observed J-shaped associations,’ the study authors concluded.
‘In addition, the combination of muscle-strengthening and aerobic activities may provide a greater benefit for reducing all-cause mortality, CVD and total cancer mortality.’
The researchers noted the available evidence was limited and said further studies, with more diverse populations, were needed to increase the certainty of the evidence.
‘The longitudinal influence of muscle-strengthening activities on mortality and NCDs [non-communicable diseases] should be further investigated with a focus on the elderly population in future studies,’ they recommended.