So, I did a little literature search this morning in some sports med journals and checked out some abstracts. The conclusion is..... inconclusive.
But...
What I can say is that everyone on this thread seems to be on the right track. One of the more recent findings in sports physiology is that there is a protective mechanism in the central nervous system (brain and spinal cord) that anticipates a blood glucose catastrophe and will refleively decrease power output.
So, if you strech this a little, well maybe a lot, and yes I am stretching, about to tear something even...
Here's my new thought, your blood glucose is dropping but rather than falling into a full bonk you end up in this state of reflexive decrease in activity due to protective mechanisms in the CNS. Now, If you've taken in a lot of easy to digest glucose and quickly stored a bunch of it because you didn't need quite that much *and* your thyroid is not able to easily help manage metabolism because of other factors. I think your body can't equilibrate the level of glucose in your blood stream easily. Because of how and what your eating as well as hormonal issues.
My newest suggestion is to eat complex carbs with a balance of protien and fat an hour, 2 might be better before a long ride, this may help to even out your glucose absoption. Then carry on with the usual recommended intake for you during exercise. Also, think about any meds you might be taking and how they affect your metabolic rate, you may need to change your med schedule. But that's something you have to talk to a doctor or pharmacist about.
CC - I hope I didn't upset you by bringing up the thyroid thing in this post, but I really think its a factor.
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