Glucose higher in endurance athletes?

Are baseline glucose values higher in endurance athletes? (just day-to-day…not during exercise)

I guess I am sorta just hoping this is true so I’m fishing for info.

got a CGM and my baseline seems to be ~105-110. I am learning that 70-100 is normal with a preference to 70-90. so I am slightly freaking out.

Found this article at the very bottom it shows Rate of disappearance of glucose in trained athletes is lower during exercise. not sure if maybe this applies after exercise also?


For starters, I’d say that you’re mis/overinterpreting that paper.

As for post exercise, not much beats training for increasing glucose removal. You can even cure overt type 2 diabetes in as little as 7 d with repeated bouts of exercise:


I figured :confused: just fishing for good news I guess.

i’ll follow up with an MD for more tests this week.

thank you for replying

Hi @genefish,

Notwithstanding the limitation of CGMs, you appear to be showing evidence of prediabetes. This is in fact common in endurance athletes for obvious reasons (we consume a lot of carbs and sugar typically - I was the same), and I had Dr Andrew Koutnik on my podcast who explains this — 30% of athletes from his studies in your boat.

The good news you can learn in the podcast is that all athletes displaying what you are alleviated the prediabetic symptoms within about 2 weeks when the altered their diet. With all due respect to your MD, they are unlikely to have any awareness of nutrition as it isn’t taught in medical school. So relatively easy solution. You can reverse your symptoms in a short period.



How, why did you get a CGM without a doc in the first place? Supersapiens?

FWIW, my morning blood glucose level is always just over 100. I’m 57 now and it’s been this way since I first noticed it on a test in my 30s. My doc said not to worry about it and no doc every since has been concerned. I’ve had a HbH1Ac test and it’s perfectly in range.

Fasted blood sugar is just one number. You can also get a glucose tolerance test and HbH1Ac.

If you don’t have any other signs of type 2 diabetes you are probably fine.

Personally, I think CGMs for ‘health and wellness’ is a mostly useless exercise. It can lead to disordered eating. The wellness influencers will tell you that if your CGM hits 200, it’s bad. If you believe this then you stop eating sugar and high glycemic foods and you end up eating low carb or keto in order to eat to the device. The body’s normal response to sugar or potatoes is an insulin spike. This is the way it’s supposed to work. It’s not ‘bad’ unless you are type 2 diabetic. In any case, don’t fall down that rabbit hole.


yeah I don’t even have an MD so I figured I’d learn as much as possible before going.

thank you I’ll check your podcast out


yes basically…one of their “competitors” Levels. some doctor that never met me wrote me a prescription…lol. can’t get supersapiens in the USA for now.

thank you for replying.

just a little surprised to see some of these spikes. it went up to 180 after 2 bananas and yogurt.

I am really just hoping to learn more about myself and see if I can spot any habits that can be improved. I eat very similar foods so if I can even change one habit it’ll be worth it. also curious what info I can pick out for on bike fueling.

agree i’m not going to eat to get a good number for the meter and the plan is to not wear this long term if it’s not providing me actionable data in the future. I’ll be careful to not obsess.

I already have changed one big habit - I have always eaten my biggest meal late at night (which includes heavy carbs). this was just partly how my day played out and partly I just enjoy eating when everything is quiet. my cgm showed my blood sugar was all over the place for the first half of the night. last night i ate my last bite 3 hours before bed…steady blood sugar all night and slept great. only sample of one night but that could be huge if it helps me sleep better…so looking for anything like that to monitor and improve on.


Speaking of CGMs:


You think that there might be a good reason for that?

CGMs are like 23andMe, i.e., they often provide data without adequate context, upsetting people and causing them to pursue unneeded follow-up, all while turning a hefty profit.


I’m surprised to see you perpetuating such myths.

ETA: For those who prefer to get their information from true experts who have built their careers around studying such issues:

About John Kirwan:


I feel like it would be tough to have true type 2 diabetes or even prediabetes as an endurance athlete with well-above-average mitochondrial function and density. Carbs isn’t the cause of diabetes.


Here’s the study. Don’t understand how that makes me “perpetuating myths”.

Highly trained competitive middle-aged athletes underwent two 31-day isocaloric diets (HCLF or LCHF) in a randomized, counterbalanced, and crossover design while controlling calories and training load. Performance, body composition, substrate oxidation, cardiometabolic, and 31-day minute-by-minute glucose (CGM) biomarkers were assessed. We demonstrated: (i) equivalent high-intensity performance (@∼85%VO2max), fasting insulin, hsCRP, and HbA1c without significant body composition changes across groups; (ii) record high peak fat oxidation rates (LCHF:1.58 ± 0.33g/min @ 86.40 ± 6.24%VO2max; 30% subjects > 1.85 g/min); (iii) higher total, LDL, and HDL cholesterol on LCHF; (iv) reduced glucose mean/median and variability on LCHF. We also found that the 31-day mean glucose on HCLF predicted 31-day glucose reductions on LCHF, and the 31-day glucose reduction on LCHF predicted LCHF peak fat oxidation rates. Interestingly, 30% of athletes had 31-day mean, median and fasting glucose > 100 mg/dL on HCLF (range: 111.68-115.19 mg/dL; consistent with pre-diabetes), also had the largest glycemic and fat oxidation response to carbohydrate restriction.

@genefish has readings of ~105-110 mg/dL. As per his other comments, he’s rightly experimenting and learning his individual responses to different foods and likely exercise.

When we ran a study comparing changing diet (low carb) or adding HIIT over 12 weeks on visceral adipose tissue (VAT) and cardiorespiratory fitness (CRF) level in overfat individuals, only diet, either in isolation or in combination with HIIT, was shown to induce a significant reduction in VAT mass and body composition variables. HIIT alone did not cause such effects on body composition, but improved exercise capacity.

What we learned in that study was that you can get fitter with HIIT, but you don’t get healthier. You need to consider the diet.

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Good video. As my colleague Jon Little explains at 7:40, high glucose readings like @genefish is experiencing cause heightened levels of advanced glycation end-products (AGEs), which ultimately contribute to faster ageing (sugar molecules sticking to other molecules in your cells like proteins and fats, causing them to not work as efficiently). This heightens inflammatory responses systemically. These also create reactive oxidation species (ROS). This creates an unhealthy athlete as Phil Maffetone and I describe in detail elsewhere. Easy solution by changing a few simple behaviours.

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The myth you’re perpetuating is that the higher amounts of carbohydrates consumed by most athletic individuals leads to diabetes. Nothing could be further from the truth, and the studies you cite don’t really address the question.

TL,DR: the best thing you can do for your “metabolic health” is 1) exercise a lot, and 2) consume something along the lines of the Mediterranean diet (which is most definitely NOT low carb).

ETA: I do have to compliment you for hitting the trifecta by citing Noakes, Vogel, and Maffetone in a single post, not one of whom is taken seriously by anybody in science/medicine.


With all due respect, please do not go on perpetuating the myth that doctors are “clueless” and that we only treat sick people (often because we are “in the pockets of Big Pharma”). T2DM prevention is directly in the wheelhouse of all PCPs. The number one tool we have is diet and exercise. Most importantly, we are able to interpret the entire patient, not a single number. If the patient were concerned, I’d get an A1c to demonstrate that their insulin sensitivity is a-okay (and while I’m doing a poke, I’ll get a BMP to check their kidneys and random glucose). CGMs are used to monitor (as is in the name) diabetes, not diagnose diabetes.


Postscript: readers are directed to this recent review regarding the use of CGM in sport


I too enjoyed this greatly. In fact, I originally created my TR forum account to tell people to disregard Noakes. I still want to know who is responsible for this fantastic Twitter account.


I’m going to have to share this account… hilarious :laughing:


Prediabetes isn’t diagnosed off of random cap glucoses (unless they’re fasted values).

With all due respect to your MD, they are unlikely to have any awareness of nutrition as it isn’t taught in medical school.

As someone who is involved in med school curriculum design/planning this is news to me! :sweat_smile: Even 20 years ago nutrition was contained in them. How much an individual physician uses this knowledge in their practice is going to be variable though, and somewhat dependent on specialty and specific practice setting.

This is in fact common in endurance athletes for obvious reasons

The incidence of diabetes in endurance athletes is lower than in the general population.


Presumably this is before the top guys started consuming up to (and maybe over) 120gCHO/hr. Should they be concerned about the long term implications of such a high consumption in both races and training.

Please no.


No. (it’s a piece I wrote on this exact concern last year.)


  1. Everything @The_Cog has said in this thread is spot on.
  2. Pancreas activity is vastly different during exercise than all other times. It makes all the difference in long-term effects.

Dental health is a much more reasonable concern.