Does exercise affect blood tests ?

Fastandfurious · Oct 20, 2005

Is there any way weight training may affect blood tests for liver function ? I'm about to have the usual checkup and want the results to be valid and show the actual picture of things,not exercise induced results.

Someone told me exercise is recognized as inflammation or a severe stressor and as such (apart from CpK and such) may contribute to higher liver enzyme showings.
Do you agree with that and if so how many ways off would it be enough to overcome this ?

Thanks for any input.

Snarf · Oct 20, 2005

Yes, intense exercise can cause elevated transaminase levels which will show up as elevated ALT/AST on a standard LFT panel. Usually, this is a mild elevation with values reporting at less than 125. However, many physicians do not know this and get spooked by any LFT abnormality.

If you can, rest from training 48-72 hours prior to your lab draw. Otherwise, figure an AST/ALT of 125 or less is pretty normal in the absence of other factors (hepatitis associated symptoms, alcohol use, APAP use, overt hepatic disease, etc).

Most labs report a normal range for LFTs between 0-40 or 0-50. Above 125 (or 2.5x ULN) (ULN=Upper Limit of Normal) docs start to get concerned. This is characterized as Grade II drug induced hepatitis. Over 250 is a Grade III event and over 500 (10x ULN) is a grade IV event.

Hope this helps.

Fastandfurious · Oct 20, 2005

This was very helpful indeed .Thank you very much.

JETHRO TULL · Oct 20, 2005

SNARF'S ANSWER WAS GREAT.

I WILL SAY YES....MY LEVELS WERE HIGH AST ALT CPK.........I HAD TRAINED 4 DAYS IN A ROW AND ON THE MORNING OF MY TEST. NOT GOOD. I HAD IT DONE A MONTH LATER AND RESTED A COUPLE DAYS AND EVERYTHING WAS BACK DOWN. FROM EVERYTHING I READ....AND I FREAKED OUT....ATHLETES ARE GOING TO HAVE HIGHER LEVELS DUE TO TRAUMA. I READ THAT IF YOU GET IN A CAR WRECK, YOUR CPK LEVELS WILL BE HIGH. SO, IF YOU'VE BEEN REGULARILY BREAKING DOWN TISSUE IN THE GYM, THOSE LEVELS WILL BE HIGH.

I'D REST A COUPLE DAYS...AND I MEAN REST BEFORE YOU GET YOUR BLOODWORK DONE. I'D ALSO GET IT DONE ON AN EMPTY STOMACH.

THAT'S MY OPINION!

dragonfire101 · Oct 20, 2005

Yes, same thing happened to me at a checkup.Exercise also also affects other things. Example I had a urine screen done for a job and the doctor reading the screen said I had protien in my urine and it was a sign of kidney malfunction and to see my primary doctor. So i did and he said it was very normal for persons who exercise or play intense sports. He said even in children who play sports this is true and sees it all the time.He said thos edoctors or nurses reading urines would not know about that all they know how to do is raed a lab report.

Fastandfurious · Oct 20, 2005

Jethro Tull,i always do a checkup on an empty stomach as per doctor's orders.Blood tests on a full stomach show too many variables out of line-especially blood sugar,triglycerides,cholesterol and perhaps even ast/alt.

Should i also stop supplements a couple days beforehand,even the milk thistle ? I think this might also help toward a more accurate result.

Kahn · Oct 20, 2005

I'd have to say if you want normal and honest readings, stop everything for three days just to be safe.

Eatbig2getbig · Oct 24, 2005

I had blood work done after doing intense leg workout the day before. My company doc. said that my liver enzymes indicated that I was headed for liver failure. In fact, he stated that if my enzyme count appeared that I was an excessive alcoholic. I got all freaked out about this thinking that it was due to gear and after talking to my personal doc. who knows a great deal about supps., training, etc. reassured me that my elevated count was most certainly due to my heavy leg training the day before. I would recc. taking it least three days off of training prior to blood work and fast for 12 hours as necessary to get an accurate blood test.
Just goes to show you that many docs. that are not used to treating athletes are not up to speed.