Just had my repeat test results from last Wednesday back (and had another blood test today) - the Wednesday after the previous Friday I had the first blood test (with no exercise done). Had a print off of the results, and they are now as follows:

Serium sodium level: 140 mmol/L (135.0 - 145.0)
Serum potassium level: 4.0 mmol/L (3.4 - 5.0)
Serum creatinine level: 116 umol/L (35.0 - 125.0)
Serum albumin level: 43 g/L (30.0 - 51.0)
Serum total bilirubin level: 11umol/L (0.0 - 17.0)
Serum alkaline phosphatase level: 101 u/L (30.0 - 135.0)
ALT/SGPT serum level: 84 u/L (0.0 - 50.0) - above average
Estimated GFR: > 60
Serum gamma-glutamyl transferase level: 26 u/L (0.0 - 51.0)
Serum creatine kinase level: 833 u/L (24.0 - 195.0) - above average

Should also add that I had my blood pressure measured when giving the blood and receiving the results and I had a pressure of 117/70 and 118/70 respectively. In addition, I had an ECG which came back as fine.

So it's dropped quite substantially in 5-days when not doing any exercise. And yes, I do always train to failure on every set - perhaps a sign of overtraining? (Will be introducing one week ever eight off to flush out CK levels from my system). Must admit I thought the doctor was going to get a specific test to rule out the heart muscle (I did suggest one and he said that was an older way of testing for it and suggested a newer test but I don't recall the name), but I can't see that in the list above (unless it's one of the ones I don't recognise?).