Analysis of the trends of creatine kinase levels during the preseason of a professional soccer team

Physical exercises can result in tissue damage on the muscular system, including during the preseason, which is a period of physical training aiming subsequent competitions. The aim of this study was to analyze the behavior of plasma CK as a marker of muscle damage during preseason of a professional soccer team; determine when preseason CK levels reach their peak value; and verify CK concentration on preceding moment to the first official match of the season. Professional soccer players (n = 31) attended this study (24.3 ± 3.9 years, 181.0 ± 7.0 cm, 9.1 ± 1.3%GC and 66.0 ± 4.5 mLO2/kg/min). The plasma concentration of CK was determined at the beginning of the preseason (M1), 4 (M2), 10 (M3) and 15 (M4) days after. We identified CK values of 178.2 ± 12.0, 540.0 ± 59.1, 389.8 ± 49.5, 408.7 ± 45.0 U/L for M1, M2, M3 and M4 respectively. The peak concentration of CK occurred on M2 (p