Kidney Health for Fitness Enthusiasts & Bodybuilders
What’s up superhumans? I realize that since most of us are into fitness and or bodybuilding so I’m going to have to expand on yesterday’s bloodwork guide.
The scariest yet most common thing jacked chads/stacy’s will hear at the NPC clown doctor upon bloodwork review? “You may have kidney disease”
A bunch of you may be laughing since you can relate to this common situation us fitness enthusiasts eventually find ourselves in, but for those who are new or haven’t had this scare yet allow me to elaborate.
There are three tests on the CMP (Complete Metabolic Panel) that are used to assess kidney function:
Creatinine
BUN
eGFR (Calculated from creatinine)
A serum creatinine test measures the level of creatinine, a waste product of muscle metabolism, in the blood. It is primarily used to evaluate kidney function, as impaired kidneys have difficulty filtering creatinine from the body.
A serum BUN (blood urea nitrogen) test measures the amount of urea nitrogen present in the blood. Elevated BUN levels may indicate impaired kidney function or other underlying conditions affecting protein metabolism or hydration status.
The estimated glomerular filtration rate (eGFR) is a calculation that uses the serum creatinine level along with other factors such as age, sex, and race to estimate the kidney's filtering capability or level of kidney function.
Here’s the problem: The reference ranges were designed for the general population and the fit lifestyle will almost always cause harmless elevation of these biomarkers. Let’s explore why:
Why Creatinine Can Be Misleading
Creatinine, as mentioned before, is a waste product of muscle. Shocking to no one, having more muscle mass than the average person will lead to higher creatinine.
A hardcore workout up to a week before your blood test will also elevate creatinine, because when you lift weights you break down muscle tissue, spilling creatinine into the blood.
Another thing that’s overlooked, that most of us do? Supplement with creatine.
Creatine metabolizes into creatinine, artificially elevating serum creatinine levels and making it appear that your kidneys aren’t functioning properly. Monohydrate is known to cause this, but creatine ethyl ester is an even worse offender.