Very informative Vet. Are you saying that overtraining alone could be the cause of very high CK level in some individuals? That would shut a lot of mouth on here and I would agree with you. I know 2 guys who went for Uralysis days following very hard leg days and showed up with blood cells in their urine, low count but still above normal.
Sort of. I'm saying that CK levels will be elevated post intense exercise. The degree of elevation is dependant on alot of factors. Capture myopathy is a disease process seen in animals secondary to extreme exertion while being captured (in a trap, net, by hand, or by being chased). Basically what happens in the animal is that muscular exertion leads to formation of lactic acid, which during extreme exercise will build up within the blood, causing a drop in blood pH. This will negatively affect heart output by affecting potassium within the blood, further making things worse because the heart won't/cant pump blood to the muscle as its needed to provide the necessary oxygen. As the muscle is damaged, the CK enzyme is released into the blood stream.
This is the same thing you see with athletes who exhert themselves in an extreme manner. It is important to determine the isoenzyme of CK that is in the blood if its present at an extreme level. CK-MM is present highest in muscle (so elevated levels indicate skeletal muscle damage), CK MB is present in the heart (So elevated levels indicate heart muscle damage) and CK BB is in the brain.
Kidney failure occurs secondary to muscle releasing myoglobin into the blood stream as its damaged. Myoglobin will severely damage the kidney, leading to further circulation problems and eventually kidney failure. If the renal tubules are damaged, you may see evidence of blood in the urine. The myoglobin is excreted by the kidney, and depending on the way the urinalysis is done, may be mistaken for hemoglobin in the urine, a marker for blood in the urine. Because of differences in the source of CK, a mildly elevated CK doesn't necessarily mean there will be renal problems, however a substantially elevated CK requires diuresis (fluid therapy) because muscle tissue is the only one present in the blood with enough mass to generate capture myopathy level CK elevations.
To me the people who are most likely at risk for an elevated CK post exercise are people like myself---Heavyweight to SHW powerlifters or other strenght athletes in intense training where maximal weights are being lifted creating a signficant short term oxygen debt (and we all know the lung conditioning of SHW powerlifters) or underconditioned gym goers who for some stupid reason get caught up in the exercise mode and do set, after set, after set without realizing they are overexerting their bodies or competitive bodybuilders who are dehydrated secondary to drugs or dieting working for a long period of time during an intense workout---say precontest. Performance Drugs may have an effect, not because they cause myositis, but because they can signficantly effect cardiovascular output starting off the cascade.