Skeletal muscle creatine kinase MB alterations in women marathon runners

Abstract

Total creatine kinase (CK) and CK MB activities were determined in gastrocnemius muscle and serum obtained from 14 female marathon runners. The level of CK MB in muscle increased significantly (pp−1) and CK MB (23 UL⁻¹) activities 24 h after the race (r=0.97,P<0.05). These results suggest that gastrocnemius muscle in women adapts to training with increased CK MB activities and imply that skeletal muscle is the major source of elevated serum CK MB activities in women marathon runners.