Example Number 2 – C Reactive Protein (CRP)

This is an example of a ultra-endurance runner who is in his early forties. He ran a hot, 100 miler in 28 hours and he suffered quite a bit after becoming dehydrated. He then recovered and finished the event. Comparing his pre and post run labs tell quite a lot about what is happening in the body during these events.



We check a hs-CRP (versus a normal CRP) and it 2.45 pre-race and it climbed to 31.94 post race. Hs-CRP stands for “heart specific C reactive protein and many people, including medical doctors actually don’t know what CRP is except that it is a measure of protein. CRP is a protein that is made in the liver, and it’s job is to go around the body and attach itself to cells that are dead or on their way to dying. So it is really a scavenger of sorts, signaling to the body which cells need to go. In the hospital, CRP increases for just about any cause of inflammation you can imagine: surgery, pneumonia, cancer, etc. In sports, an increased CRP usually signifies that damage to muscle has occurred. It also raises if there is liver or intestinal damage. I once saw a CRP jump to the 600’s in a patient after a cyclocross race; which is a one hour high intensity bicycle race. I observe the same thing in UFC fighters after their fights.


Ferritin is a protein that stores iron in the short term. Ferritin is also a protein of inflammation, just as is CRP. Ferritin often goes up in tangent with CRP and it is because there is iron released from damaged cells that the ferritin must carry. The body works very hard to make sure there is no free forms of iron floating around the body. The ferritin jumped from 90 pre-race to 240 after the race. Again, we see this same pattern in the hospital. The fact that ferritin can increase so suddenly is the reason it is not a good idea to check it when you are sick or after a very hard training session or race. We know that it is going to be elevated and it is not a good indicator of iron storage in this case.


Just as the LFT’s increased in the first example of the female triathlete, we see that this runners LFT’s also increased. Although not nearly as high as triathletes LFT’s, but they are pretty high nonetheless. The increase from normal levels to the 100’s is a pretty typical response in a well trained athlete. The LFT’s usually go back down after some days. One can only speculate why the LFT’s did not increase into the 1000’s, but it probably has to do with blood flow to the liver during exercise.

Cholesterol Profile

We checked a super fancy lipid panel called a NMR Lipoprotein Assay pre and post race. It needs to be remembered that this individual is a fat adapted athlete and consumes a significant portion of his calories from fat. Also his body is able to burn fat for energy much more efficiently than someone who is not fat adapted. It is interesting that the LDL Particle count dropped from 1624 to 1315 after the race. The LDL dropped from 165 to 150 and the cholesterol remained about the same.

Cholesterol Metabolism and Prolonged Exercise

A large contribution of lipid oxidation to energy supply during prolonged exercise is a major source of energy. Most lab tests show reduced LDL and triglyceride levels immediately and 24 h post marathon. Total cholesterol, HDL and LDL levels are usually decreased at the end of a prolonged exercise session. Most fat is stored as triglyceride in fat and muscle cells. Plasma and muscular triglyceride are consumed equally during the early stages of endurance exercise, and subsequently the free fatty acid become the major source of energy. This can explain the reduction in triglyceride at the end of the race. Cholesterol levels normally decrease after prolonged exercise and cholesterol levels are not affected by changes in plasma volume post-exercise. It must be remembered that cholesterol is our bodies first responder to inflammation. The lipoproteins that carry cholesterol are shuttled around during periods of inflammation to the tissues that most need them. Every cell in the body needs cholesterol. So it is no wonder that the cholesterol levels found in the blood are decreased by significant amount. It is reasonable that cholesterol is being used throughout the body after a prolonged exercise.







I hope these examples of lab changes after long exercise doesn’t raise concern about the health benefits of exercise. But it should raise awareness about the dose and intensity of exercise and how it can affect your body. It should also make you think about the health of your liver and other organs and your decision to take part in a Triathlon or Ultra endurance event. For example, if you have metabolic syndrome or fatty liver disease, it is reasonable that your liver may endure more stress than if you did not have these problems. Exercise is a healthy output and benefits us all.