Investigating Muscle Damage and Inflammation Markers

Venous blood samples were collected into K₂EDTA-coated vacutainers (BD Biosciences, Franklin Lakes, NJ, USA) for analyses of DNA methylation and mRNA expression. Serum samples were isolated from venous blood samples collected in silica-coated vacutainers (BD Biosciences, Franklin Lakes, NJ, USA) for the determination of protein markers of muscle damage and inflammatory cytokines at the Pre-ex, Post-ex, Post-ex + 1 h, Post-ex + 3 h and Post-ex + 48 h timepoints (Figure 1B). Blood cell counts were also performed at each time point using a Yumizen H500 system (Horiba Medical, Kyoto, Japan). Skeletal muscle biopsies were obtained for the determination of DNA methylation and mRNA expression from 6 of the 8 participants (2 participants opted out of biopsies but completed the remaining parts of the study). Following collection, the skeletal muscle tissue was blotted dry and any visible fat or connective tissue was removed, snap-frozen in liquid nitrogen and stored at −80 °C prior to the analysis.