BACKGROUND AND PURPOSE:

• The guidelines for minimum physical activity levels needed to maintain a healthy lifestyle are the same for adults of all ages
• Martinez-Gomez et al. (JAMA Network Open, 2024) explored whether there is an age-dependent association between physical activity and all-cause mortality

METHODS:

• Cohort study (4 population-based prospective cohorts)
  • National Health Interview Survey (1997 to 2018) | UK Biobank (2006 to 2010) | China Kadoorie Biobank (2004 to 2008) | Mei Jau (1997 to 2016)
• Exposure
  • Self-reported leisure-time physical activity
  • Age group
• Study design
  • Cox proportional hazards regression models with stratification by study were used to calculate mortality hazard ratios
• Primary outcome
  • Death

RESULTS:

• 2,011,186 individuals
  • Mean age: 49.1 (SD, 14.3 | Range, 20 to 97) years
  • Women: 55.0%
  • Median follow-up: 11.5 (IQR, 9.3 to 13.5) years
• The association between physical activity and mortality in the total sample showed a nonlinear dose-response pattern
• Physical activity was consistently associated with a lower risk of mortality across all age groups
  • The reduction in risk was greater in older vs younger age groups, especially at high levels of physical activity
  • Age modified this association (P_interaction<0.001)
  • Greatest reduction in risk in older adults was observed at physical activity levels 4 to 5 times higher than current recommendations
• Overall mortality hazard with recommended physical activity
  • Hazard ratio (HR) 0.78 (95% CI, 0.77 to 0.79)
• Meeting physical activity levels was positively associated with modifiable risk factors
  • High educational level | Not smoking |Healthy body weigh | No hypertension | No diabetes
  • Age modified the associations of these modifiable health factors with mortality (all P_interaction<0.001)
  • The magnitude of associations was greater in younger vs older age groups

CONCLUSION:

• Meeting physical activity recommendations was associated with reduced mortality risk throughout adulthood
• The benefit of physical activity may actually increase slightly with age
• Other modifiable health factors such as not smoking also reduced mortality, but unlike physical activity their benefit decreased with increasing age
• The authors state

In this pooled analysis of cohort studies, the association between PA and mortality risk remained consistent across the adult lifespan. This contrasts with other modifiable health factors, including educational level, smoking, alcohol consumption, body weight, hypertension, and diabetes, where we observed that their associations with mortality risk diminished with age

Given these findings, the promotion of regular PA is essential at all stages of adult life

Learn More – Primary Sources:

Physical Activity and All-Cause Mortality by Age in 4 Multinational Megacohorts