Objective: Creatine kinase (CK) is an enzyme that is expressed in higher proportions in skeletal and heart muscle, lower concentration in brain tissue. It may be used to determine injury of skeletal and heart muscle. Creatine kinase-myocardial isoenzyme (CK-MB) is a good indicator that is used by the diagnosis for myocardial infarcts and also inflammatory skeletal muscle diseases. The aim of this study was to examine the effects of acute exercise on CK, CK-MB levels in sedentary male subjects. Thus, exercise induced muscle injury levels will be determined.

Materials and Methods: Total of 50 male subjects were participated. Subjects performed an acute aerobic exercise work load corresponded to 50-80% of maximal heart rate. Venous blood samples were drawn before and at the end of the exercise. CK, CK-MB levels were measured using autoanalyser.

Results: CK and CK-MB levels were both increased significantly in all subjects. During exercise, CK-MB level, as evaluated in terms of percent change is increased more than CK levels.

Conclusion: These results indicated that exercise induced muscle injury significantly increases CK, CK-MB levels. The observation of higher increases in CK-MB levels during acute exercise may reveal the heart muscle injury.