Subject characteristics are reported as median (IQR) and proportions (IQR) for continuous and categorical variables, respectively. The aim was to explore any associations between biomarkers and each of the four PA classes. The analyses were divided into three steps. In the first step, unadjusted (crude) analyses were performed, with the biomarker as the dependent variable and each PA class as independent. Biomarker concentrations were transformed to the log2 scale.