The longevity benefit of physical activity may remain consistent regardless of age

Key takeaways:

• Physical activity corresponded with reduced risk for death at all ages.
• The association between physical activity and mortality risk grew stronger with increasing age.

The beneficial impact of physical activity on mortality risk remained consistent across the adult lifespan, even growing stronger later in life, according to study results published in JAMA Open Network.

In contrast, other modifiable health factors saw their effects on the risk for mortality decrease with increasing age.

Several prior studies have tied various levels of physical activity, even 11 minutes of walking daily, to reduced risks for death from all or specific causes.

“However, it is unclear, but plausible, that this association may differ by age,” David Martinez-Gomez, PhD, an associate professor in the department of preventive medicine and public health at the Autonomous University of Madrid in Spain, and colleagues wrote.

They noted that the same amount of physical activity — 150 to 300 minutes of moderate-intensity physical activity, 75 to 150 minutes of vigorous-intensity physical activity or a combination of both — is recommended for adults of all ages.

Understanding the links between physical activity and the risk for death across age groups “is vital for tailoring age-specific physical activity recommendations to optimize health benefits throughout the adult lifespan,” they wrote.

In the study, the researchers used data from four population-based cohort studies — the U.K. Biobank, National Health Interview Survey, Mei Jau and China Kadoorie Biobank — to determine how age impacts not just the positive effects of physical activity on mortality risk but the benefits of five other modifiable health factors.

Such factors included a high educational level, not regularly drinking alcohol, not smoking, maintaining a healthy body weight and living without diabetes or hypertension.

Analyses were done for the total sample and by age groups, which were 20 to 29 years, 30 to 39 years, 40 to 49 years, 50 to 59 years, 60 to 69 years, 70 to 79 years and 80 years or older.

The total sample comprised 2,011,186 individuals aged 20 to 97 years (mean age, 49 years; 55% women), among whom 177,436 deaths occurred during a median follow-up of 11.5 years.

The reduced risk for mortality varied by physical activity levels. For example, meeting half the recommended amount of physical activity reduced the risk by 8%, while having five times the recommended amount lowered the risk by 26%.

The researchers found that physical activity consistently reduced the risk for death across all age groups, although the risk reduction — especially at high levels of physical activity — was greater among older adults vs. younger adults.

The HRs for mortality tied to meeting the recommended physical activity vs. not meeting the recommendations were:

• 0.78 (95% CI, 0.77-0.79) for the total sample;
• 0.84 (95% CI, 0.76-0.93) for those aged 20 to 29 years; and
• 0.78 (95% CI, 0.75-0.81) for those aged 80 years or older.

Age also modified the beneficial effects of the additional modifiable health factors on mortality risk, but these benefits diminished as age increased, with the associations more pronounced in younger vs. older age groups.

“It is crucial to communicate to adults that engaging in an adequate amount of physical activity remains critically important throughout the lifespan, gaining even greater importance as one ages,” Martinez and colleagues concluded. “Policy actions must be addressed to facilitate and promote desired amounts of physical activity that can promote physical activity engagement and sustainability at all stages of adult life.”