Abstract
The aim of this study was to assess how much risk a resistance exercise can provide to individuals who have distinguished hyperCKemia response. Twenty-three healthy men performed an exercise protocol, during which 4 sets of biceps curl were performed at 85% of 1 repetition maximum (1RM). Each bout was performed to voluntary fatigue and the workout volume completed was calculated. Subjects provided blood samples prior, and at 24, and 48 h following exercise to evaluate serum creatine kinase (CK) activity. Based on serum CK activity responses the subjects were separated into two groups called: Normal Responders (NR) or High Responders (HR). A great interindividual variability in serum CK activity following exercise and a significant difference between NR and HR were observed. The workout volume demonstrated a significant reduction along sets but without difference between NR and HR. Our main finding was the great inter-individual variability in serum CK activity that is seen even when using a single exercise performed on a the day-to-day basis.