The creatine kinase response to resistance exercise.

Area of Science:

• Exercise Physiology
• Biochemistry
• Sports Medicine

Background:

• Resistance exercise induces localized muscle tissue damage, affecting cellular structures like the sarcolemma and contractile elements.
• This damage leads to the release of intracellular enzymes, including creatine kinase (CK) and lactate dehydrogenase, and proteins like myoglobin into circulation.

Purpose of the Study:

• To review the mechanisms by which resistance exercise increases circulating creatine kinase (CK).
• To identify and discuss factors influencing the CK response to resistance exercise.
• To evaluate the utility of serum CK as a marker for training status and overtraining.

Main Methods:

• Literature review focusing on studies investigating muscle damage markers after resistance exercise.
• Analysis of factors affecting serum CK levels, including interindividual variability, training status, muscle groups, and gender.
• Discussion of the physiological basis for CK release and its interpretation in sports science.

Main Results:

• Serum CK is a commonly used, cost-effective indicator of muscle damage following resistance exercise.
• Significant interindividual variability exists in serum CK responses to exercise.
• Factors such as training history, specific muscle groups trained, and gender can significantly impact CK levels, often more than exercise volume.

Conclusions:

• While elevated serum CK indicates muscle damage, its high variability and susceptibility to confounding factors limit its reliability as a sole indicator of training intensity or overtraining.
• Further research is needed to establish more precise reference ranges and contextualize CK levels within individual athlete profiles.
• Understanding the multifactorial influences on CK response is crucial for accurate interpretation in athletic monitoring.