Leisure time, occupational aerobic physical activity, and mortality risk in adults of United States: National Health Nutrition and Examination Survey 2007-2016

Abstract

Objectives: Regular aerobic physical activity (PA) is recommended in the Physical Activity Guidelines of the United States. We investigated whether both leisure time physical activity (LTPA) and occupational physical activity (OPA) reduce mortality. Methods: We analysed physical activity data of 28 735 participants and mortality data of 18 498 participants aged 18 to 64 years in the United States National Health and Examination Survey 2007-2016 using R 3.6.1. Results: The proportions of participants having ≥150 min/week of moderate intensity aerobic PA or equivalent from LTPA, OPA and total PA were 39.6% (38.0%-41.2%), 37.5% (36.2%-38.7%) and 61.7% (60.6%-62.9%), respectively. For survival analysis, the median follow-up was 4.8 (interquartile range=2.8-6.8) years. Log rank test showed that all the groups with ≥150 min/week of LTPA had higher survival compared with the group with no PA (all P<0.001), whereas the groups having ≥150 min/week of OPA but <150 min/week of LTPA did not have higher survival (P=0.166, 0.584). In stratified multivariable Cox regression, LTPA ≥150 min/week (hazard ratio [HR]=0.48, 95% confidence interval [CI]=0.33-0.69) with 50≤OPA<100 min/week (HR=0.31, 95% CI=0.14-0.71) was associated with lower all-cause mortality. In contrast, 150≤OPA<300 min/week and OPA ≥300 min/week were not (HR=0.63, 95% CI=0.27-1.47; HR=1.02, 95% CI=0.68-1.53, respectively). Conclusions: Adults doing ≥150 min/week of moderate intensity or equivalent LTPA have half the risk of death. Occupational physical activity is not associated with lower mortality. Our findings support the differentiation between LTPA and OPA in the guidelines. Leisure time physical activity should be encouraged, especially since more than half of adult Americans do not have enough aerobic exercises from LTPA.