The Acute Response of Irisin and Brain-derived Neurotrophic Factor in Blood to Resistance Exercise Load

In this study, the investigators will examine how three resistance training protocols acutely affect BDNF levels (in serum, plasma, platelet count, and BDNF per platelet) and irisin levels in blood (plasma). The resistance training protocols will differ in intensity, rest intervals between sets and repetition execution. Blood samples will be collected from participants at four time points: before the start of the protocol, 5 minutes after completion of the final set, 1 hour after completion of the final set, and 3 hours after completion of the final set. In addition, blood lactate levels will be monitored at the same time points. Heart rate will also be recorded (immediately before the start of the protocol and 30 seconds after completion of the final set). A control protocol will also be implemented, in which blood will be collected at the same time points. Data will be collected across five visits to the kinesiology laboratory at the University of Ljubljana, Faculty of Sport. Each visit will last approximately 4 hours, except for the first visit where 1RM will be measured.