Is it necessary to adjust current creatine kinase reference ranges to reflect levels found in professional footballers?

Objective We aimed to explore the validity of applying current reference ranges of the enzyme creatine kinase (CK) when analysing the medical status of professional footballers and to offer a more functional CK reference range for professional footballers. Methods A sample of 27 professional male footballers competing in The Football League Championship was analysed. The single sample Wilcoxon signed-rank test was used to compare the CK distribution of the study group with that of a control group of military personnel reported in the literature. Results The median values for study group and the published control group were 284 U/L and 124 U/L, respectively (P