Reflotron plus

To determine blood lactate and CK concentrations, aliquots of blood were obtained from a finger-prick sample. Blood lactate was directly analysed using an automated analyser (2300 STAT plus, Yellow Springs Instruments Inc., Ohio, USA) in duplicate. A 32 µl sample of blood was pipetted onto a CK Test Strip (Reflotron® Plus, Roche Diagnostics, UK) and analysed in duplicate using a commercially available Reflotron CK Assay (Reflotron® Plus, Roche Diagnostics, UK). Self-ratings of perceived quadriceps muscle soreness were assessed using a 10 point scale ranging from 1 (not sore) to 10 (very, very sore) (35) while the participants stood.

Thirty minutes after each training session, the players were asked to provide an RPE rating, using the modified CR10-scale by Foster [11] (link). All players were familiarized with the RPE scale prior to the commencement of the study. Players were prompted to track their RPE individually using a customdesigned application on a portable computer tablet. Each player selected their RPE rating by touching the respective score on the tablet, which was then automatically saved to the player's profile. This method helped minimise factors that could influence a player's RPE rating, such as peer pressure and replicating other players' ratings [43] . Each individual RPE value was multiplied by the session duration to generate a session-RPE (s-RPE) value [12] (link)[13] [14] .
Forty-eight hours before the matches, we measured the concentration of plasma CK found in each player [7] . To accomplish this, the skin was first cleaned using a 95% ethyl alcohol. After drying, 32 μL of capillary blood was collected using an automatic lancet. The blood was saved in a heparinized capillary tube (Reflotron Plus, Roche Diagnostics) and immediately pipetted onto a reactive CK strip (Reflotron Plus, Roche Diagnostics), to be placed in a Boehringer Mannheim Reflotron Analyser®.