Between 30 and 60 minutes of resistance training activity every week is linked to a 10-20% lower risk of death from all causes.
Physical activity guidelines recommend regular resistance training that strengthens the muscles for adults, primarily because of the known benefits for skeletal muscle health. Lifting weights, training with resistance bands and heavy gardening constitute as adequate resistance training.
Historically, research has indicated that resistance training activity that strengthens muscles is associated with a lower risk of death, but it is unknown what the optimal dose might be. The researchers sought to figure out this unknown phenomenon, and they scoured research databases for relevant prospective observational studies that included adults without major health issues who had been monitored for two years or more.
The data analysis was published online in the British Journal of Sports Medicine.
Analysis of resistance training and health outcomes
The final analysis included 16 studies out of an initial selection of 29. The earliest study was published in 2012, and most studies were carried out in the USA, with the rest from England, Scotland, Australia, and Japan. The maximum monitoring period lasted 25 years.
Study participant numbers varied from nearly 4,000 to almost 480,000, and the age range was from 18 to 97. Twelve studies included both men and women; two included just men, and three included only women. All the studies considered aerobic or other types of physical activity as well as resistance training activities.
The pooled data analysis highlighted that resistance training activities were associated with a 10-17% lower risk of death from any cause, as well as death from heart disease and stroke, cancer, diabetes, and lung cancer.
However, no association was found between resistance training and a reduced risk of specific types of cancer, including those of the bowel, kidney, bladder, or pancreas.
The emergence of a J-shaped curve
A J-shaped curve emerged, with a maximum risk reduction of between 10-20% at approximately 30-60 of resistance training activities that strengthens muscle for death from any cause, cardiovascular disease, and all cancer.
The researchers discovered an L-shaped association was observed for diabetes, with a large risk reduction up to 60 minutes a week of resistance training activities, after which there was a gradual tapering off.
Joint analysis of muscle-strengthening resistance training and aerobic activities showed that the reduction in risk of death from any cause, cardiovascular disease, and cancer was even greater when these two types of activities were combined: 40%, 46%, and 28% lower, respectively.
The researchers acknowledged certain limitations to their findings, the main one was that data from only a few studies were pooled for each of the outcomes studied. The included studies also relied on subjective assessment of resistance training activities. Additionally, the majority of the studies were carried out in the US, the results may not be widely applicable, and the studies were observational rather than clinical trials.
The researchers noted that given the J-shaped associations, the potential of a higher volume of resistance training activities on the reduction in risk of death is unclear. However, they concluded that: “The combination of muscle strengthening and aerobic activities may provide a greater benefit for reducing all-cause, [cardiovascular disease], and total cancer mortality.
“Given that the available data are limited, further studies—such as studies focusing on a more diverse population—are needed to increase the certainty of the evidence.”
