Does weight lifting decrease all-cause risk of death? Original paper

To maximize health and longevity, the World Health Organization (WHO) recommends that adults perform 150–300 minutes of moderate-intensity or 75–150 minutes of vigorous-intensity aerobic physical activity and 2 or more resistance-exercise (e.g., weight lifting) sessions per week.^[1] Although performing moderate-to-vigorous aerobic activity is consistently associated with a reduced risk of all-cause mortality,^[2] the relationship between resistance exercise and all-cause mortality is less clear.

This prospective cohort study examined the association between weight lifting and all-cause mortality in 99,713 adults (average age of 71; average BMI of 28) in the United States over an average follow-up time of 9.6 years. In 2006, the participants completed a questionnaire on the frequency of their weight lifting and moderate-to-vigorous aerobic activity over the previous 12 months.

All-cause mortality was the primary outcome. Analyses were also conducted to assess whether weight lifting and moderate-to-vigorous aerobic activity altered all-cause mortality risk and to determine primary causes of death (i.e., cardiovascular disease or cancer). The results were adjusted for a number of potential confounders, including age, sex, education, BMI, alcohol consumption, smoking status, and comorbidites (i.e., coexisting conditions). The analyses for weight lifting were only adjusted for aerobic physical activity.

Only 23% of the participants reported performing any weight lifting, and 16% lifted weights 1–6 times per week. For moderate-to-vigorous aerobic activity, 31.6% met or exceeded the WHO recommendations.

Compared with not doing weight lifting, performing weight lifting was associated with a lowered risk of all-cause mortality:

• Less than once per month to 7+ times per week: 9% lowered risk
• 1–2 times per week: 14% lowered risk
• 3–7+ times per week : 7% lowered risk

Weight lifting was also associated with a lower risk of cardiovascular disease mortality:

• Any weight lifting: 9% lower risk
• 1–3 times per month: 11% lower risk
• 1–2 times per week: 15% lower risk

For cancer mortality, weight lifting 1–3 times per month was associated with a 15% lower risk.

In the joint analysis, compared with inactive participants, the reduction in all-cause mortality risk was highest among the participants who performed weight lifting 1–3 times per month or 1–2 times per week and met or exceeded the WHO recommendations for moderate-to-vigorous aerobic physical activity:

• 1–3 times per month and met recommendations: 44% lower risk
• 1–3 times per month and exceeded recommendations: 45% lower risk
• 1–2 times per week and met recommendations: 41% lower risk
• 1–2 times per week and exceeded recommendations: 47% lower risk

A limitation of this study is that it assessed weight lifting and aerobic activity frequency at only one time point, so it did not account for potential changes in exercise routine over time. The analysis also lacked details about the weight lifting routines (e.g., intensity, load, and volume).