Combination of muscle strengthening and aerobic exercise linked to reduced mortality risk

For older adults, combinations of aerobic and muscle-strengthening activities might lower the risk for all-cause mortality, according to researchers.

Adults aged older than 65 years should participate in muscle-strengthening activities (MSAs) 2 or more days per week, and moderate to vigorous aerobic physical activity (MVPA) for 150 or 75 minutes, depending on the intensity of the exercise, according to current HHS recommendations.

Previous research has shown that exercise can not only reduce mortality risk, but also help boost mental health.

The current research, published in JAMA Network Open, aligns with other recent studies that indicate combinations of exercising with weights and aerobic exercise may lower the risk for mortality from any cause except cancer.

Bryant J. Webber, MD, MPH, of CDC’s division of nutrition, physical activity and obesity, and colleagues conducted the cohort study to explore “the dose-response association between MSA and all-cause mortality in older adults,” both independent of MVPA and combined with it.

The researchers analyzed data from 115,489 participants who responded to the 1998-2018 National Health Interview Survey. They calculated weekly MVPA and defined four levels by weekly minutes (<10, 10-149, 150-300 and >300). They also defined four levels of MSA by weekly episodes (0-1, 2-3, 4-6 and 7-28). The researchers then used Cox regression, adjusting for factors like age, race and ethnicity, sex and more, to determine hazard ratios and 95% confidence intervals for all-cause mortality.

Of the participants, about 57.3% were women, 57.8% were aged 65 to 74 years and 80.4% were white. During the nearly 8-year follow-up period, about 45,000 deaths occurred, and “no interaction was evident between MSA and MVPA categories.”

Compared with fewer than two MSA episodes, the researchers found that two to three MSA episodes (adjusted HR = 0.83; 95% CI, 0.79-0.87) and four to six MSA episodes (aHR = 0.79; 95% CI, 0.72-0.86) per week were linked to a lower all-cause mortality risk, after adjusting for MVPA. Notably, the findings were not replicated for those with seven to 28 episodes per week, according to the researchers.

Compared with less than 10 minutes of MVPA per week, 10 to 149 minutes (aHR = 0.83; 95% CI, 0.81-0.86), 150 to 300 minutes (aHR = 0.75; 95% CI, 0.72-0.78), and more than 300 minutes (aHR = 0.68; 95% CI, 0.66-0.71) per week were associated with a lower all-cause mortality risk, after adjusting for MSA.

However, combinations of both MSA and MVPA saw lower mortality risks. Adults aged 65 to 85 years who met both MSA and MVPA guidelines had a significantly lower risk for all-cause mortality compared with those who met neither guideline:

• aHR = 0.68; 95% CI, 0.64-0.73 for adults aged 65 to 74 years;
• aHR = 0.74; 95% CI, 0.69-0.79 for adults aged 75 to 84 years.

“Leisure time MSA and MVPA were independently associated with lower all-cause mortality in this cohort study of U.S. adults aged 65 years or older,” Webber and colleagues wrote. “By using finer age and physical activity categories, a larger sample, and longer follow-up, we build on earlier studies and offer new insights for older adults and their health care professionals.”

They noted that a “U-shaped dose-response between MSA and mortality, independent of aerobic physical activity,” indicates that somewhere between two and six episodes per week “may be optimal.”

“This study highlights the mortality benefit of both MSA and MVPA for older adults of any age,” the researchers concluded.