Does running skew cholesterol test? (Read 203 times)


    My annual checkup is coming up, and I will fast for 12 hours before the blood test. The test is on Thursday morning, should I skip my normal run Wednesday night? Does exercise skew the results one way or the other? But running every day is now "normal" for me, so I don't know... I just don't want to get invalid results and waste my trip and copay to the doc.

      I've never had it affect my cholesterol level, but a hard workout has affected my CREATININE level.

      Petco Run/Walk/Wag 5k

        I'm not a doctor but was told by my Cardiologist not to run/walk/exercise before fasting blood tests because it can affect some of the tests they do. Not sure about cholesterol but would imagine it would affect at least glucose

        bob e v
        2014 goals: keep on running! Is there anything more than that?

        Complete the last 3 races in the Austin Distance Challenge, Rogue 30k, 3M Half, Austin Full

        Break the 1000 mi barrier!

        History: blessed heart attack 3/15/2008; c25k july 2008 first 5k 10/26/2008 on 62nd birthday.

          I have a test coming up in 2 days.  Hadn't really given this any thought - since I run every morning, seems like that is my "normal".  Interested in hearing replies from med professionals here.

          Well at least someone here is making relevance to the subject. - S.J.

          Feeling the growl again

            Over time, for many people, LDL will be lowered.  "High" mileage can have the effect of also raising HDL, so in combination your ratio would be improved.  This is not a universal, guaranteed phenominon, we are all individuals.


            As to the effect of a single run, I have not seen any studies on this but I would not expect it to have a significant effect.  I have run and not run before tests and the results are always about the same.

            "If you want to be a bad a$s, then do what a bad a$s does.  There's your pep talk for today.  Go Run." -- Slo_Hand


            I am spaniel - Crusher of Treadmills


            Jon the Freshman

              It most likely won't have an affect considering cholesterol is gained/lost gradually not overnight. That being said you may have other skewed results that your doctor may want to continue testing you for. I recently experienced from my own blood test where my bilirubin, liver enzyme, was elevated. I did a little research and discovered that bilirubin is responsible for recycling red blood cells. Considering the fact that I was doing hard interval repeats at that point in my training I considered that to be acceptable and has never caused me any health issues. Also I tested high for thyroid enzymes as well, but again seeing as my metabolism would be elevated from competing I again saw no reason for concern. All things considered, train how you like and when the results come in don't entirely rely on your doc's interpretation.


                I remember someone (I think it was Trent) said that the triglycerides value can vary a lot even throughout the day, but I don't know if running will cause it to go out of whack. I was mainly thinking about HDL/LDL/trig numbers because my doc flagged them in previous years, but the test do analyze a bunch of other stuff as well, which I hope will not suddenly get screwy because of me working out the night before. Maybe I should take the cautious approach and just keep the run very easy and not do anything long or hard, without really knowing why (but I do want to know. Just curiosity.)


                  On my last test I also had the Dr tell me that I had a high bilirubin level and I most likely had something called Gilberts syndrome after checking and finding the level was cause by dead red blood cells, I think my daily running was the cause for this level but all my other levels were awesome.



                    Last bloodwork I had,  I had run to the doctor's office. Liver enzymes were up but cholesterol was unaffected.




                      I did a quick lit search and found this:  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1859549/pdf/brjsmed00268-0037.pdf


                      In this study of males (of varied age and fitness levels), their cholesterol levels were elevated from baseline during and immediately after exercise.


                      I would interpret those results with caution, however.  For example, if you don't fit into the study population (e.g.,  if you are female), the study results may not be applicable to you.  In addition, although reasonably designed, the study was a relatively small one.


                      Here is another study that addresses this question.

                      J Sports Med Phys Fitness. 1988 Mar;28(1):7-10.

                      The effects of acute physical exercise on blood serum cholesterol, triglycerides, human growth hormone (H.G.H.) and free thyroxine (T4) in men over fifty years of age.

                      Métivier G, Gauthier R


                      However, I can't access the full paper on the road, so I can't comment on the study or results.  (Obviously, this study would not necessarily apply to you if you are a female or a male under 50 years of age).


                      Other than that, I couldn't find a lot that addresses your specific question.


                      You may wish to skip that morning's run, so that you remove the possible influence of short term exercise on your results.  (If you don't, and you get an abnormal results, you'll probably end up spending more money to make sure it was real).


                      Good luck--hope this helps a little..


                      PS:  The other comments about glucose level are probably correct (although not as much as you might think--assuming you aren't a diabetic, have liver disease, etc.).    Other possible labs that might be influenced would be your hemoglobin/hematocrit if you grossly overhydrate or underhydrate on a lengthy training run in unfavorable weather.  Also, if you have a vigorous run, your creatine kinase might be bumped a bit (but that test is not part of the usual health maintenance labs..

                        I just had my mandatory  health assessment for work last Wednesday.   All numbers were pretty much normal, however, my cholesterol was the highest it has been in the last six years, at 200 mg/dl.  However, my HDL was also the highest it has been as well at 77 mg/dl, which was good.   I did run that morning before the test, which I have done most years.   I should also note  I am at the peak of training for a Sept Marathon, and my mileage is the highest it has been in the past few years.  Others mentioned it would affect  glucose level,however, I didn't see this.   I ran a hard 10 mile tempo run 3 hours before my blood draw and it was the same as it has been in other years.  Here's my cholesterol history:


                        2013 - 200 mg/dl

                        2012 - 181

                        2011 - 151

                        2010 - 176

                        2009 - 177

                        2008 - 180