Well, you're technically disagreeing with my nephrologist. lol. I'm just regurgitating what he tells me concerning elevated creatinine and BUN in people who exercise intensely. From what he has told me and what I've read, intense exercise can show false readings concerning kidney function levels. Creatine alone is not a good indicator of actual kidney function in athletes, especially strength athletes. Other tests like cystatin c (CC), Urine albumin-to-creatinine ratio (UACR), BUN, and Creatinine all need to all be looked at together to gauge true kidney function. A 24 hour urine collection also has to be done. Even if those blood tests come back out of whack, a kidney tissue biopsy is usually needed for a good diagnosis to happen. This all had to take place in my case to get my diagnosis anyway.
I'm not trying to be argumentative, btw, but BUN and creatinine will show up elevated a lot of the time in strength athletes. I totally do feel like he needs to get it looked at, though. I just don't want to sound alarmist. That is counter productive. Know what I mean?