Definition creatine kinase
Creatine kinase (CK) is an enyzm. It is found in skeletal muscle, heart, brain and smooth muscle with their three isoenzymes CK-MM (muscle type), CK-MB (heart type) and CK-BB (brain type). The determination of CK activity is used in medicine for the diagnosis of diseases of the heart and skeletal muscle. In sports science it is considered for training diagnostics and training control.
Significance in training diagonistics
Creatine kinase is the key enzyme in anaerobic-alactic energy production. Creatine kinase enters the blood through the permeability disorder (increased permeability) of the muscle cell wall during intense exercise. They indicate the intensity of the load. In particular, unaccustomed and new stimulus-effective training loads lead to an increase in creatine kinase activity. This activity of creatine kinase can last up to five days after exercise. During exercise, CK activity can increase up to ten to twenty times the resting value. A load change or reduction is necessary if creatine kinase rises too sharply. Therefore, the highest values are not measured directly after the athletic performance, but only hours later (cf. Clasing/ Siegfried). However, if the values are constantly elevated after the night’s rest, it can be assumed that the stress is too intense.
The limits of the normal range are 80 U/l. With continuous training, values up to 200 U/l can be taken for granted. Values above 300 U/l indicate abnormal cell wall permeability. Structural changes are to be expected here.