Objective This study aims to explore the association between physical activity and high-sensitivity C reactive protein, based on different types of physical activity—occupational and leisure time.

Methods Using cross-sectional data from the Korea National Health and Nutrition Examination Survey 2015–2018, we explored the association between different types of self-reported physical activity and high levels of high-sensitivity C reactive protein (>3 mg/L). We estimated the ORs for high-level high-sensitivity C reactive protein using multiple logistic regression models after adjusting for covariates from 12 970 eligible subjects (mean age 44.8).

Results Compared with subjects who did not engage in moderate-to-vigorous level of occupational physical activity (OPA), the group that engaged in moderate-to-vigorous level of OPA showed a significantly high OR (1.32, 95% CI (1.03 to 1.69)), whereas the group that engaged in moderate-to-vigorous level of leisure-time physical activity (LPA) yielded a low OR (0.84, 95% CI (0.69 to 1.01)). The group that engaged in moderate-to-vigorous level of OPA but not LPA showed a significantly high OR (1.76, 95% CI (1.27 to 2.45)) compared with subjects who engaged in moderate-to-vigorous level of LPA but not in OPA.

Conclusions OPA is directly associated with high C reactive protein levels, suggesting that it increases the risk of inflammation.