These microscopic tears are normal and do not lead to injury, but they do allow CPK to enter the bloodstream. CPK values may be used to evaluate an athlete's response to limited types of training stimuli. AST is an enzyme found in the liver and muscle tissues. As well, elevated AST values may be a sign of liver or coronary damage. Cortisol is a hormone secreted by the kidney in response to psychological or physiological stress.
Cortisol increases the rate of breakdown of proteins, carbohydrates and fats.
In times of stress, cortisol allows energy sources to mobilize to provide additional energy requirements. However, when cortisol levels are elevated over a prolonged period, the body can start to break down muscle in order to meet energy requirements. LDH is an enzyme found in the muscle, heart and liver. LDH levels may be elevated following intense exercise or in associated with liver or coronary disease. Hematology Red Blood Cells .