Who Gets 67 C-Reactive Protein Tests? I do!


My very first C-Reactive Protein test was from a blood draw taken November 20th, 2015. It was in bold and made clear I was in deep, deep trouble. Here were the reference ranges:

My score? 14.3!!!

Ironically, this was also when I got my first NMR as well.

After some panicky message passing to my doctor, I found he wasn’t quite as worried once I gave the context. It has been two days after (1) I had finished a half marathon and (2) gotten terribly sick afterward (nausea, vomiting, etc). He said this can happen with runners and wanted to test again in three months.

Eff that, I thought. I’m going to pay out of pocket and test in two weeks, along with getting another NMR.

You already know about this two week period from many of my podcast interviews and presentations, but you’ve never heard me talk about CRP before. The reason for that is simple — my doctor was right — my next CRP was just 0.63. And for the next eight tests afterward, it would be under 1.0.

Sedentary Phase December 2015 to July 2016

During this period I was intentionally avoiding any intensive exercise. I typically fit in a walk of around 2-3 miles a day, but would otherwise keep from anything very exhaustive. This was due to my wanting to control this variable for my research.

Of the nine CRPs from that period, five took place over the Identical Diet Experiment I took with my sister that summer.

I was impressed at just how consistent they were. Not only were each under 1.0, but the marker was 0.31 at the lowest, 0.69 at the highest for just a 0.38 delta. That’s pretty small.

Overall, I was pretty happy to see the consistently low numbers, further emphasizing the original 14.3 was indeed related to both the exercise and getting sick. Little did I know I was about to confirm each would boost this number independently. That… and that this would actually be my third highest score!

Exercise Phase August 2016 to January 2017

Things changed quite a bit when I added exercise back in. Remember, I had quite a schedule of races during that period:

  • August 22nd – Training and exercise phase starts
  • Sept 24th, 25th – 10k and half marathon – Couldn’t do blood tests as we were in Paris
  • November 5th-6th – 10k and half marathon
  • November 12th-13th – 10k and half marathon
  • January 4th-8th – 5k, 10k, half marathon (canceled), full marathon

Knowing in advance what the previous half marathon did with my CRP, I was especially curious what my numbers would look like when taken 24 hours after a race.

Needless to say, we have plenty of confirmation these running phases certainly had an impact on my markers.

Sedentary January to August 2017

Generally, I was focusing on many experiments over this period of time. Starting at around April, most of the experiments involved various versions of carb-swapping, so I wasn’t sure what effect it might have on my CRP. But overall it appeared to hold pretty steady.

However, I did have one period of time where I got sick during an experiment in February. My CRP happened to reflect this with a sustained bump over that period of time quite prominently (although nowhere near as dramatically as the distance running.

As I’ve talked about with Siobhan many times over, I’ll try to be mindful to get regular blood testing the next time I get sick as I’m very interested in having that data for further comparison.


One Last Half Marathon

My wife and I did one more 10k followed by a half marathon on November 11th and 12th, respectively.

Without surprise, I saw my CRP rise in the test taken 24 hours after, then return to baseline as I expected.

The Mysterious September 12th

Okay, so we have a seemingly strong narrative that explains every bump in CRP to be sickness and/or exercise. But what about September 12th? I didn’t mark it for either.

As it happens, that’s when I was doing my first additive carb experiment (which I haven’t had a chance to do a post on). However, the test the morning of the 12th was the baseline. In other words, I hadn’t yet ingested any carbs by that point, so carbs can’t be suspected.

There was one thing that stood out about that time: stress.

Just before that, I was in the process of launching the Patreon. At my current rate of savings depletion I was going to be in bad shape were I not to do something soon. So I was finally taking the advice I was given countless times before after reaching a bit of a stretch point.

So in a sense, it wasn’t just money stress by itself, it was also the stress of hurriedly putting together the Patreon and getting it ready to launch. But moreover, I’ll concede it was actually difficult for me to request the help. I’ll have more about this fateful time in my book. But needless to say, it was a challenging period of time in my life and I wouldn’t be surprised if my stress levels were at much higher than normal levels.

Was that the real reason? Your guess is as good as mine.

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Raf C
Raf C
2 years ago

Just added you on Patreon. It’s not much, but it’s what I can do for now to help out your continuing research. Cheers.

Benjamin Kuo
Benjamin Kuo
2 years ago

This makes me feel much better. I got an inexplicable 3.0 on my test in January. I dug out my training log and found out I had just done a really long run the day before.

Mark G
Mark G
2 years ago

This is a little off-topic for this post, but… I understand you started this journey with a high glucose result. How is all of this affecting your glucose?

2 years ago

I had a CRP test result come back at 10.9. Yikes! I’m prediabetic and had an extremely stress filled week and went to the ER due radiating pain in my chest/stomach area prior to the test. I assumed the high CRP score was caused by eating too many carbs but stress/sickness may have played a part in it also, am I correct? I was able to lower the CRP score in 3 months to 2.5. by eating a keto diet.

Siobhan Huggins
2 years ago
Reply to  Linda

Yes, sickness for sure can influence CRP. I’ve tested CRP while I was sick even with mild colds, it ranged from 0.5-1 (normal/healthy) to 48 (fairly sick/fever).
If you suspect you were sick when you got tested, getting a retest when you feel better might be warranted. Sickness can also affect other markers too (including your lipid panel, depending on the illness!).
I’m not sure about stress, but chronic stress is tied to things like worsened insulin resistance, so there’s certainly a possibility.
Exercise can also influence CRP… it’s a finicky test, but combined with other markers it can be helpful to determine over all health. Taken alone, it can result in some confusion.

John Wolverton
2 years ago

Dave, great work that I have just become aware of. As a follow engineer (Electrical and Systems) the first question I have is, “How do you baseline your system?” Followed by if I make a valuestream map of the curren system what do I want the future state to look like? Data driven decisions should drive any change and it seems the current medical system is not equipped to do this. So how do we do this? Thoughts?

1 year ago

I’m an average LCHF guy and I practice a 16/8 daily fasting schedule. Recently I went two week experiment of getting into full-on >20g of net carbs and protein to 1.5x body weight. To simplify things I ate the two same meals for lunch and dinner everyday and I do high intensity resistance training 3x per week. I was also calorie deficit but tried as I could, I just wasn’t hungry and didn’t care to eat more.

My glucose hit personal bests below my average of 105 mg/dL and my HBA1C came in at 5.3%. Kidneys and Liver tests came back clean. Lipdis are as expected: HDL normal, LDL elevated and Triglycerides below normal. TG/HDL ration are 0.8 (mmoL) and 1.8 (mg/dL) respectively.

However my HS C-Reactive protein came in at 9.2 mg/L and my doctor was alarmed as it’s 3x higher than the cutoff for high-risk. Reading this gave me some comfort because the day before the test was a hard day at the gym. While I didn’t do a half-marathon like Dave, I push myself hard each workout. Maybe it was a mistake to take a test less than 24H after that session.

I was wondering, based on how I work out, how then should I get a solid read on inflammation in my body? Should wait a few days after a strenuous workout? A week? The big goal here is to determine: is there inflammation in my body that puts me at risk of heart disease despite my other measures?

Any thoughts on this Dave? Thanks for all your work!

Siobhan Huggins
1 year ago
Reply to  Taffy

Based on other active people who’d done the test, and had the pleasure of troubleshooting, it seems best to avoid strenuous exercise for a few days leading into the test.

What's the frequency, Kenneth?
What's the frequency, Kenneth?
1 year ago

You indicated that stress can cause elevated CRP. I was on an extended fast when I had a battery of tests done. I know fasting is supposed to be stressful, though it’s often hard to tell after the first few days, as…hormones. Do you think this could explain a CRP of 5.2?

FWIW, I know that I’m insulin resistant, and have been in ketosis for about six months. My A1C is down to 4.8 from 7.2, and I’ve dropped over 1/4 of my all-time-high body weight in less than a year.

Siobhan Huggins
1 year ago

When I did an extended fast (7 days) my CRP/inflammatory markers were lower, not higher. However, hs-CRP can go up for a variety of reasons.
For example, did you do exercise prior to the blood draw (morning of or in days leading up)? Were you feeling under the weather at all? It might be worth a re-test under more “normal” circumstances, e.g. fasting 12-14 hours water only after eating normally for the week prior.

Andrea Farinacci
Andrea Farinacci
1 year ago

Hi – I’ve been LCHF for 5 mos- just tested my C-Reactive Protein and it almost doubled from 0.7-1.3.
I’ve since started with a Vit C and Magnesium supplementation. When should I test again? That jump surprised me. Any thoughts?

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