Sorry
@Replenished for delay in replying. From what you describe it does sound like 'hitting the wall' or the bonk - a condition of sudden fatigue and loss of energy which is caused by the depletion of glycogen stores in the liver and muscles. When the body switches fuels from carbohydrate to fat burning, there's an intermediate step of protein recycling within cells (not muscle breakdown) that fuels the body for about an hour before your body ramps up lipolysis (fat breakdown) and production of ketones. You were probably attempting intense exercise during this transition period - essentially the same as 'hitting the wall'. Not long before this transition begins there's usually hunger or cravings. I found a high fat zero carb meal like Salmon helped quell such hunger and get me into Ketosis. Another option is MCT oil which the body supposedly can quickly convert into ketones.
I wonder, is the muscle fatigue in 'hitting the wall' a direct result of energy starvation within the muscle cells? Or is it created within the brain (to make you stop exercise) in order to protect itself? - since the brains requirement for energy takes precedence.
Sounds like stopping the diet was absolutely the right thing to do - since you know that's safe. And because some other action based on a wrong assumption could possibly result in loss of consciousness. If you were wearing a Continuous Glucose Monitor to ensure blood glucose remained at a safe level then you could experiment (without stopping the diet) with small amounts of clean (non-toxic) carbohydrate fuels like berries or a teaspoon of raw dark honey.
I wonder, could you have provided fuel for the body without raising insulin?
My thoughts about exogenous ketone supplements: Research has shown the overall effect of the ingested BHB is to decrease lipolysis (fat breakdown) - not what you want. And it would do nothing to restore depleted glycogen stores. Not good.
What about Fructose? Fructose does not raise insulin. It is converted into glucose and glycogen mainly within the liver and also within muscle cells. Hence the suggestion of fruit or honey (in above preceding paragraph).
What about honey - different opinions - generally not recommended until you're metabolically healthy!
Is Honey Okay on the Carnivore Diet?
Is Honey Carnivore/Animal-Based? -
My apologies to original poster. I was too quick to dogmatically preach the 100% pure carnivore diet - that is recommended for people with autoimmune conditions like ME/CFS. If you find honey works for you, good for you!