Collection of blood samples
BLOOD
Blood samples were obtained from the participants at three different time points: before the commencement of the first training session (pretest), immediately after the first training session (acute post-test), and 48 h after the final training session (chronic post-test). Blood (5 mL) was drawn from a cubital vein into pyrogen-free tubes without EDTA by venipuncture. Notably, sampling was performed after approximately 12 h of fasting. Blood samples were then centrifuged at 3000 rpm for 15 min at 4 °C, and serum was transferred to a 200-µL microcentrifuge tube and stored at −80 °C until further analysis. Serum levels of AMPK, PGC-1α, irisin, IGF-1, and MSTN were analyzed using enzyme-linked immunosorbent assay kits for humans (Shanghai Meilian Bioengineering Institute, Shanghai, China), with a sensitivity of 1.0 ng/mL, 1.0 nmol/L, 1.0 ng/mL, 1.0 ng/mL, and 0.1 ng/mL, respectively. The intra- and inter-assay coefficients of variability for all blood markers were less than 10% and 15%, respectively.