Association between work-related physical activity and mortality among US Cohort.

Purpose: The benefits of leisure-time physical activity (LTPA) in reducing mortality are well-known, while the relationship between work-related physical activity (WRPA) and mortality remains controversial. The study aimed to investigate the association between WRPA and mortality, and to determine whether LTPA should be recommended in a population with a high level of WRPA.

Method: Data were obtained from a sample of adults aged 20-80 years included in the National Health and Nutrition Examination Survey (NHANES) cohort from 2007 to 2018. Hazard ratios (HRs) for the association between WRPA and all-cause mortality were estimated using Cox proportional regression models. All analyses were performed in accordance with NHANES guidelines, in which data were complex-weighted first and then analyzed in the next step, Statistical significance was defined as a two-sided P-value < 0.05.

Results: A total of 27,567 participants were included in the study. Over a median follow-up period of 78 months, a total of 2,553 (weighted ratio, 6.5%) participants were assumed dead. The mean age (SD) of this cohort was 47.5 (16.7), and 48.5% were men. Compared to participants without WRPA (as the reference group), participants engaged in WRPA exhibited a significantly reduced risk of all-cause mortality over different time periods. Specifically, the HR for participants with less than 17.5 h of weekly participation were 0.70 (95% CI: 0.62-0.78). For those participating between 17.5 and 35 h per week, the HR was 0.80 (95% CI: 0.64-1.00), while participants engaging in more than 35 h of weekly participation had an HR of 0.71 (95% CI: 0.56-0.91).

Conclusions: WRPA is a protective factor that reduces the risk of all-cause death, especially in people without LTPA.