Serum Creatine Kinase Isoenzyme CK-MB Following Isometric Exercise

Abstract

Serum levels of creatine kinase (CK) isoenzymes were evaluated in 12 untrained male subjects after three different isometric exercises; one-arm flexion (OAF), two-arm flexion (TAF), and one-leg knee extension (OLE). The serum level of CK isoenzyme MB (CK-MB) was elevated after at least one of the exercises in 50% of the subjects tested. There was no relation between elevated CK-MB level and the type of exercise performed (Totals for OAF = 3, TAF = 3, and OLE = 3). When an elevated CK-MB level was noted, it occurred after the first bout of exercise in five of six subjects and was not so prevalent after the second (two of six) and third (two of six) exercise bouts. Similar results have been noted for total serum CK and suggest that skeletal muscle is affected by an initial bout of exercise.