Elevated CPK Levels

I am a 17 year old boy that runs track 3-5 days a week and works out frequently; I am more or less in top physical shape. I have a relatively low heart rate (~50-60) and have had high cholesterol for the past few years. Last Tuesday, my aunt took a sample of my blood to check for my cholesterol and found that I had extremely high levels of CPK. (544 U/l). This immediately frightened me so I looked it up online and saw that elevated levels of CPK was related with heart attacks, muscle damage, and renal failure. My aunt believes that this elevated concentration of CPK is in fact due to my running workouts and weight training routines (I ran Monday, the day before she took blood) so she decided to take blood again on Friday (even though I ran again on Wednesday). This time, the numbers came down slightly to 474 U/l. On Saturday, I went to see my doctor and he believes that its also because of my strenuous workouts. Is this possible? I haven't heard of any cases online where a person has elevated amounts of CPK in his/her blood due to working out.

Also: My troponin is low (< 0.02 ng/mL), TSH is 1.53 uIU/ml and cholesterol is 212.

[MamaBush]

Yes, CPK levels can rise due to working out.

CPK levels indicate muscle damage, which is common when working out the way you work out.  If you would discontinue your workouts, your CPK levels would go down as your muscles heal.  VERY COMMON.