Originally Posted by
elcruxio
So many questions...
Failed the glucose tolerance test how? Were you having a high blood glucose or low? And how was the test performed? Also, why is that given to anyone in a normal checkup is really weird. Did they do a fasting blood glucose test first?
Also considering you ate a high carb diet for a while, you may gotten a chronic high blood sugar. After you've been high for a while, when you come back down to normal levels you're going to have the symptoms of hypoglycemia.
And one option is just that something triggered a hypoglycemia disorder which would have started in any case at some point. It does happen. But you average healthy person doesn't get that from eating carbs. If something, they can get type 2 diabetes, where depending on the type of type 2, one symptom actually is having hypoglycemias.
My doctor ordered a fasting glucose tolerance test when I reported in with my symptoms. I don't remember the numbers, but the message from the diabetes doc was that my test was abnormal and that I should cut back on carbs and increase fat and protein in my diet. He said I was in the range of being pre-diabetic. I immediately incorporated those changes in my diet.
I doubt that it would have happened anyway. I'd never had a blood sugar problem and wasn't overweight or sedentary. And this was back before I started serious cycling, so maybe 25 years ago. Cycling has helped, particularly working with Chapple's principles for improving fat burning, but the base problem is still there. I have to be careful. A favorite afternoon snack is now an ounce of walnuts or a jigger of virgin olive oil or a piece of cheese, rather than toast and jam.
If one experiences the OP's lethargy symptoms on a ride, the advice is to eat and the best thing is high G.I. carbs. As you say, that works great on a ride, but it's not good advice if one is experiencing blood sugar swings off the bike, which IMO is what the OP is experiencing. It's not normal for me or anyone I ride with to experience lethargy after a ride. OTOH I don't feel like going dancing either, just a little normal tiredness.