Occupational Physical Activity and Mortality Risk: Evidence From a Nationally Representative US Sample (National...

Leisure-time physical activity is associated with health benefits, whereas occupational physical activity (OPA) may, paradoxically, increase health risks. This study examined associations between OPA and mortality in a representative US sample.

Data from 8041 full-time workers (age 41.4 ± 0.2 y) in the 1999-2006 National Health and Nutrition Examination Survey, linked to the 2019 National Death Index, were analyzed. Self-reported occupations were categorized as low, moderate, or high OPA. Cox proportional hazards models estimated adjusted hazard ratios (aHR) for all-cause and cardiovascular disease (CVD) mortality, adjusting for demographics, health behaviors, and health status. Effect modification by age, sex, race/ethnicity, education, smoking, and leisure-time physical activity was examined.

Moderate OPA was associated with higher all-cause mortality (aHR = 1.24, 95% CI, 1.00-1.53) compared with low OPA. Moderate (aHR = 1.79, 95% CI, 1.16-2.75) and high OPA (aHR = 1.71, 95% CI, 1.00-2.92) showed higher CVD mortality risk. Adults aged ≤44 years and females with high OPA had higher all-cause mortality risk compared with low OPA (aHR = 1.60, 95% CI, 1.00-2.57 and aHR = 1.59, 95% CI, 1.05-2.41; respectively). Among never smokers, those with some college education, and those meeting leisure-time physical activity guidelines, high OPA was associated with increased CVD mortality (aHR = 3.44, 95% CI, 1.26-9.37; aHR = 3.50, 95% CI, 1.60-7.64; and aHR = 6.21, 95% CI, 2.10-18.39; respectively).

This analysis supports the physical activity health paradox in a US population, with higher OPA levels associated with increased mortality risk, particularly from CVD. These findings underscore the need for targeted workplace interventions, especially for vulnerable populations.