Strength Training Linked to Less Premature Mortality, CVD, and Diabetes

Hitting the gym to lift some weights appears to both reduce the risk of all-cause mortality and lower the risk of developing noncommunicable diseases (NCDs), such as cancer and cardiovascular disease, according to the results of a new meta-analysis.

The maximum benefit was observed among those who performed strength-based physical activity for 30 to 60 minutes each week, a finding that “suggested that optimal doses of muscle-strengthening activities for the prevention of all-cause death, cardiovascular disease, and total cancer may exist,” according to lead investigator Haruki Momma, PhD (Tohoku University Graduate School of Medicine, Miyagi, Japan).

Moreover, when researchers analyzed the combined effects of aerobic and strength-based exercise, the benefits were additive, with a 40%, 60%, and 28% lower risk of death from any cause, cardiovascular disease, and cancer, respectively.

“Based on these findings, the combination of muscle-strengthening and aerobic activities may provide a greater benefit,” Momma told TCTMD via email. “For those with aerobic activities, it is recommended to add muscle-strengthening exercises into daily life.”

Several guidelines for physical activity, including those from the United States and World Health Organization, advocate for regular muscle-strengthening exercise for adults, but the current Japanese guidelines do not make such a recommendation, said Momma. A revision of the Japanese physical activity guidelines is currently underway, and there is some debate as to whether strength-based activity should be included as part of the next iteration. Momma noted that existing guidelines for physical activity primarily focus on the musculoskeletal benefits of resistance training—gains in muscle/bone strength and improved physical function—so they wanted to support future recommendations by providing some evidence on its effects on premature mortality and NCDs.

Dose-Response Curves

The meta-analysis, released this week in the British Journal of Sports Medicine, included 16 studies published between 2012 and 2020. The studies, most of which were conducted in the United States (others in England, Scotland, Australia, and Japan), included a mix of men and women, and the maximum duration of follow-up was 25.2 years.

My stand is that muscle-strengthening activities could never replace aerobic activities in recommendations and guidelines. Haruki Momma

In seven studies with 42,133 deaths among 263,058 participants, muscle-strengthening exercise was associated with a significant 15% lower risk of all-cause mortality. A nonlinear relationship was observed, with the lowest risk of all-cause mortality seen in those who performed 40 minutes of muscle-strengthening exercises each week. For CVD, in which there were seven studies with 16,056 cases among 257,888 participants, muscle-strengthening activity was associated with a significant 17% lower risk. Again, a J-shaped relationship was observed, with maximum benefit seen in those who worked out 60 minutes each week.

Muscle-strengthening exercise was associated with a significant 12% lower risk of cancer and the maximum benefit was seen in those who did 30 minutes of strength work each week.

Resistance training also lowered the risk of diabetes, but there was a different relationship observed with volume. Specifically, the risk declined in those who performed up until 60 minutes per week of activity, a point that was followed by a gradual decrease in benefit. With diabetes, said Momma, “a clear dose-response association can be established because muscle-strengthening activities increase or preserve skeletal muscle mass, which has been identified as the major tissue in glucose metabolism.”

In terms of the dose-response, Momma said there is still much to learn about the optimal volume of muscle-strengthening exercise for reducing the risk of death and NCDs, as well as the optimal intensity and type of workouts. Given their findings, though, a recommendation of at least 2 days per week of weight-based training is reasonable. “However, my stand is that muscle-strengthening activities could never replace aerobic activities in recommendations and guidelines,” said Momma. 

The researchers acknowledge several study limitations, including the limited number of studies and the potential for publication bias that may have overestimated the pooled reductions in risk. Also, given that the majority of studies were performed in the US, generalizability of the findings to other populations is difficult.