Creatine kinase
80 μl of capillary blood were collected from the participants’ earlobe and immediately centrifuged (Universal 320 R, Andreas Hettich GmbH, Tufflingen, Germany) for 10 min at 3000 rounds per minute. After centrifugation, 10 μl of blood plasma was collected with a reusable pipette (Eppendorf Research Plus, Eppendorf, Hamburg, Germany), pipetted on a dry slide reagent, and analyzed in a point-of-care-testing system (DRI-CHEM Analyzer FDC NX500, Fujifilm Europe, Duesseldorf, Germany). Post-exercise samples were manually diluted in the form of a dilution series (1:2; 1:4; 1:8; 1:16; 1:32; 1:64), using a concentrated 0.9% sodium chloride solution. The lowest dilution was placed on the dry slide reagent for analysis, and if the value was not detectable, the next highest dilution was applied. Finally, the undiluted value was calculated by multiplying the diluted value with the dilution factor.