What is Creatine Kinase and Why is it Important?

Do you feel muscle pain, nausea, weakness, and dehydration right after an intense workout? While it may be normal and might be due to over-exercising, it might actually indicate something more serious if the symptoms are severe and continue for a long time. In this case you may need to check your creatine kinase levels. The doctor might diagnose you with a condition called rhabdomyolosis, and tell you that this occurred from being a gym rat. Rhabdomyolosis occurs when muscle fibre in your body gets damaged and it triggers release of creatine kinase in your system.

A rise in creatine kinase may also be caused due to taking of cholesterol-lowering drugs called statins, by a heart attack, by a stroke (or other brain damage) or finally by many other muscular disorders.

What is creatine kinase?

Creatine kinase, or CK for short, is an enzyme present in your heart, skeletal, brain and other tissue muscles.

This enzyme’s activity is highest in striated muscle (MM isoenzyme), brain (BB isoenzyme), and heart tissue (MB isoenzyme). Its concentrations are reflective of muscle mass, therefore, males have higher concentrations of it than females.

Any elevation of CK in our blood is normally deemed to be an implicit marker of muscle destruction, specifically for diagnosis of conditions such as myocardial infarction (heart attack) or any other type of heart damage, skeletal muscle disease (Muscular dystrophy), skeletal muscle damage (strenuous training, injury, drug induced such as statins), cerebral damage (stroke).

Why is it important to track the levels of this enzyme?

High levels of creatine kinase indicate damage to muscle tissue, heart muscle, or the brain.

So, if you have high levels of CK, it is most like that you have muscle tissue injury. After muscle damage, CPK leaks into the bloodstream. Doctors try to find out which type of CPK is high in order to determine which tissue has been damaged.

The test may be performed to:

  • Diagnose heart attack
  • Determine the extent of the muscle damage
  • Diagnose muscle disease such as dermatomyositis, polymyositis, rhabdomyolysis, etc.

Exercise induced elevation in CK

Pain is a common indicator of muscle damage but is generally not useful for establishing the extent of injury. For this reason, creatine kinase is often measured to diagnose and evaluate muscle damage.  There isn’t yet a universally agreed level of exercise induced CK elevation where one would define as over-exercise. However, whenever you experience dark brown urine (coca-cola urine) or typical symptoms of a so called exercise induced rhabdomyolysis (muscle pains, poor urine output, muscle weakness, fatigue, soreness), then please report immediately to a local medical center for a quick CK level and urine myoglobin test. Typically if the CK is above 5000 U/L, without any evidence of heart attack or stroke, then exercise induced rhabdomyolysis is probable and IV fluids is given with rest to prevent kidney failure.

As an athlete or body builder, your diet may contain more carbohydrates and proteins, always well hydrated, replace lost electrolytes and go easy on fats. Both the hydration and good dieting will ensure healthy kidneys. Full hydration and limiting your routine to the usual tolerable range can avoid getting to excessive muscle damage and rhabdomyolysis.

Nutritional deficiency?

When your elevated CK cannot be explained by muscle injury (to the heart, brain, or skeletal), it may be an indication of nutritional deficiency. This should be a decision made by your doctor, and it is a rare occurrence.

The nutritional elements that can cause persistent elevation of CK are not well documented but consider these: Vitamin D, vitamin B12, Magnesium (all of which can be tracked by a simple blood test), and carnitine or coenzyme Q10.

When to see a doctor?

You should see your doctor immediately if you have any of the symptoms that indicate a high creatine kinase level. The symptoms may be: shortness of breath, chest pain, muscle pain, nausea, and extreme fatigue.

As an athlete and body builder, watch for dark coloured urine, reduced urine output, weakness, persistent muscle pains, and fatigue. The presence of these require a quick CK level and urine myoglobulin. If elevated to certain levels you require IV hydration to prevent kidney damage.


Creatine kinase (CK), also known as creatine phosphokinase (CPK), is an enzyme mostly found in the skeletal muscles, brain and heart. A high level of creatine kinase occurs when the heart muscle is damaged during a heart attack. You may also have high CK levels if you have damaged your skeletal muscles or brain. It is very important that you track this biomarker. If you are a gym freak, don’t over-exert if you have high CK levels. Keep to the usual routine. Try to follow a heart-healthy diet and maintain a healthy lifestyle.

If you’re interested in learning more about creatine kinase, how it affects your body and what it indicates about your health, read on more about it in our biomarker post here!

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