I've always had somewhat high fasting blood sugar levels. It hasn't climbed over the years, but I'm usually in the 100-110 level, and I think anything above 100 is considered high. Like you, I'm very fit and have a healthy diet. I don't know if it's connected to training or to the high level of simple carbs consumed as fuel, but it's always been concerning.

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-Andrew

What was the number? If you think it was abnormal, a $15 meter from CVS comes with 10 strips for you to test on your own.

What does your Dr say? That seems like a more important opinion than the insurance company.

X2, what was the fasting reading?

 I am in excellent shape. Over the last 6 years, I have averaged 10-15 hours a week on the bike year around. Resting heart rate mid 30's to low 40's, 6' 160 pounds. I have a very clean diet. I have been sitting at about 100 on my blood sugar levels for the last 4 years which puts me at a pre diabetic state. I have not seen seen any hard data on this but I think its common for chronic endurance athletes to have elevated blood sugar levels.

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BoulderCyclingCoach.com

when the "new" standards for fasting blood sugar came out (or they were new to me, anyway - 2001), it was 103. I had to laugh when my doc's nurse called and told me I was pre diabetic - they didn't like my total cholesterol either; despite a great HDL ratio. Anyway, the laugh part was when the nurse said I should consider an exercise program. I said if I did anymore exercise I'd have to quit working.

Now, I just do at least a medium intensity swim before going in and having my blood drawn. Solves the "you may want to consider an exercise program" conversation.

Ironically, a few year ago my brother in law and I had a bet; he also is fairly active. About a half an hour after a holiday feast, complete with wine and dessert, we decided to take our blood sugar - lowest one wins. We both thought for sure that we'd need immediate hospitalization with our numbers. Mine was just below 100.

Sometimes, even though I love data as much as the next tri geek; I wonder if we don't get a bit wound up about our numbers being off by such small fractions. My single digit IQ never bothers me (Ignorance is bliss). :-|

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I saw this on a white board in a window box at my daughters middle school...
List of what life owes you:
1. __________
2. __________
3. __________

My fasting glucose was 87 when I was tested last year which is in the normal range. My A1C however is in the prediabetic range at 5.7-5.8 over the past year (5.7 is the lower limit for prediabetes).

My doctor is not too concerned because it is staying stable. I think its partly genetic because others in my family have had blood sugar issues as well.

I always get questioned about my resting heart rate. It was 38 when they checked me last month.

I'm not aware of any reason training should lead to elevated blood sugars--on the contrary, athletic activity is usually thought to have the opposite effect, in particular leading to the opposite of insulin resistance, i.e. sensitizing the tissues to insulin (which is why diabetics often have to be careful with exogenous insulin post-workout).

It's worth keeping in mind that the "normal" range of blood sugars are values that are normal for the majority of the population and aren't bounded by hard and fast thresholds. The numbers are most useful both over time (are they changing?) and in the context of the bigger health picture.

Another nuance is that blood sugar levels appear to be markers of other dynamics, e.g. inflammation, down into the normal spectrum. Average blood sugar, as measured by A1c, correlates with heart disease risks well below the diabetic threshold.

But there are also other reasons why one might have elevated blood sugar having nothing to do with such dynamics--for example, monogenetic mutations that may upregulate the glucose thermostat without many of the health consequences associated with elevated blood sugar caused by more typical mechanisms. If blood sugars are only modestly elevated and don't worsen much over time and aren't very susceptible to other interventions (diet, oral meds, insulin), that would all suggest a possible monogenetic cause (regular diabetes, both T1 and T2, of course also has genetic drivers, but so far the link is far weaker).

If we were going to play lay doctor, it'd be useful to know some things about body weight, diet, fitness, and if possible also fasting blood sugar, glucose tolerance (which is pretty easy to do at home), and average blood sugar (HbA1c). That would start to map out a picture one could interpret.

that straight-up glucose test doesn't mean much, esp for a 1-off test. lots of factors come into play.

an hgba1c test is more meaningful...but there are some reasons where it can be misleading.

when did you last work out? had you been in a hard training block leading into the tests?

I would be interested to know if it is coincidence or if exercise just keeps blood sugar extremely stable. Fasted or fed, by glucose levels are always between 90-100. It would be interesting to see what they are after a race, too.

My fasting glucose levels have always been just below 100 as well, even when seriously training or the day after doing a significant workout (long run or long bike). It's always worried me a bit, so it is good to know that others are seeing a similar thing, I guess.

I heard somewhere that the A1C being high is more because it's also a bit of a reflection of the volume of blood sugar you process over the past month(s). So an endurance athlete's is naturally going to be a bit on the high side. A bit, but not tons.

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My blood sugar been on the normal side even when not fasting. Last annual test I did, I went not fasting because I am always up early for workouts and didn't want to just workout without eating anything so had my usual pre workout food, did the workout, didn't eat anything after the workout and went to get my test done. Came back just above the normal range.

My guess is your body tap into your glucose while exercising and my blood was a just a little too sweet.

Couple weeks later, my company had on site testing and got mine done again and it was in the 80s (non fasting) but about 3 or 4 hours after my morning workout, even though I was eating all morning. So who knows!

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Did my yearly exam/labs with my PCP in January. My fasting BS came back high 101 (range 65-99). Since my previous BS levels ran in the low 90's range he said lets do an A1C just to be on the safe side.

My A1C was 5.3. (Range <5.7 Consistent with the absence of diabetes.)

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Train safe & smart
Bob

Nope. A1c just measures average blood sugar over roughly the past three months weighted to recent weeks. Basically, glucose bonds to red blood cells in proportion to its presence in the bloodstream. So consuming carbs only raises your A1c if it raises your blood sugars. One additional variable is that people's red blood cells have varying lifespans, and if exercise affects those lifespans, it would also affect the A1c (if those red blood cells stick around longer, more opportunities to become glycated, and vice versa).

Same here. Right at 100 on last 3 physicals. My doc said it's the volume of training the quantity of food that flows through my system every week. I'm not a big guy (170 lbs), but eat a bunch to keep weight up. She said I'd probably see this until volume dropped below 7-9 hours per week for a long period of time/

Interesting. I'd like to know how training load and fueling can cause insulin resistance.

I think her argument in my case was more of a lack of insulin to keep up with the amount of glucose I'm producing with what she would argue is too many calories of a rich carb diet. She thinks lower volume = lower consumption = better bloodsugar balance. In an interesting twist, I mostly ran in the offseason (minimal bike/swim) and it was lower versus the middle of my tri season.

Right, that's more like I had heard. Red blood cells see more glycation (sugar exposure) in an endurance athlete because of higher blood sugars from the fueling while training (hopefully just while training). The catch is that higher blood sugar while exercising does NOT raise insulin, so you aren't becoming insulin resistant from it. It's insulin resistance that's the problem, and A1c isn't the best test because it throws a false-positive of sorts. Simply resting blood sugar might be better. Theoretically, if you eat sugary stuff (in moderation) while exercising and stay away from it while not, then you're good to go. Your body will burn it off before it can have a detrimental effect. The problem is when people keep pouring high-octane fuel into their gas tank when the car is just sitting still and then it starts spilling all over the place and the next thing you know you're face-to-face with Sea Bass in the restroom, 3am in a Colorado truck stop.

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Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

That's reasonable, though exercise also does a fantastic job of keeping blood sugars in check. So if you're spiking your blood sugars by fueling during exercise, you're probably overfueling. And insulin resistance isn't primarily produced by the presence of insulin--it's produced by other things (like getting fat, or for that matter just consuming fats which end up in the bloodstream), and in response to that insulin resistance the body puts more insulin into the blood.

Right. I think the problem is that because some is good, people think even more is better. They start eating simple carbs and overeating in general all the time. What's a nice performance enhancer starts becoming toxic. Like caffeine, water, alcohol, drugs, libertarians, pet wolves... easy foods seem like a great idea at first, but the aftershock is not so pretty.

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Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

Eating fat can cause insulin resistance? I know being fat is a risk factor....

Yep. Insulin sensitivity isn't some static thing, it fluctuates, and one sure-fire way to quickly increase your insulin resistance is to consume a high-fat meal that increases the lipids circulating in your bloodstream. Which doesn't automatically mean it's a bad thing...

Agreed! Outside of exercise, simple carbs, and overdoses of carbs in general, are nasty stuff. Like gasoline on a fire--in appropriate context and moderation, an amazing fuel; in excess or in the wrong circumstances, catastrophic. I hate when people say the problem with sugar is it's not nutritious--the problem with sugar is that it's *too* nutritious!

My husband's was running above 100 (fasted) and his A1C was pre-diabetic. He's a pretty lean fit guy that does tris. Being more careful about his sugar intake brought his A1C back just below the pre-diabetic range. No more sweet tea, much smaller servings of ice cream and far less frequently, and I started watching our high glycemic carb meal inputs. His doctor seems to think that Type 2 in eventually inevitable for him, but we might as well keep it at bay for as long as possible.