I am speculating here, but you just might have a case of
glycogen storage disease type 0, which is a deficiency in the glycogen synthase enzyme. If this is the case, the you cannot synthesize glycogen in the liver and / or muscles, which means that under circumstances where your pancreas is secreting glucagon to stimulate your liver to release glucose into the blood stream, the liver cannot comply, since it lacks the glycogen storage form of the glucose.
Now you may think that the circumstances under which your pancreas secretes glucagon are limited, but in fact, glucagon is secreted pretty much after every mixed meal, approximately 2 hours after ingestion. You eat, insulin is produced by the pancreas, this lowers blood sugar a bit too much, but the pancreas secretes glucagon shortly after the insulin to goose glucose levels back and maintain normoglycemia. There are only two types of meals that do not follow this pattern: high carbohydrate and pure fat.
If you do have this pathology, fasting for you is a bad idea. During the first 24 hours of a fast, normal individuals are relying on stored glycogen for energy. If you don't have any glycogen to speak of, that is obviously only going to result in you going hypoglycemic. Further, there is simply no way for you to "train yourself" into releasing glucose to tide you over during your intermittent fasts ... your metabolism is simply incapable of this mode of operation.
There is also another broader implication here. If you decide to train, and specifically, train by adopting conventional grok wisdom using sprints, you are dead meat ( exaggerating here ). Sprinting is an anaerobic activity meaning that it relies largely on fast twitch muscle which in turn relies heavily on glycolytic respiration. Which brings us back to the fact that folks with glycogen synthase disease don't have any glycogen to spare, which means that glycolysis is not going to go very far for them, and fatigue will set in much more quickly than for a normal individual. Training for such a person would be a challenge, and they would have to avoid short intense bursts of activity, instead relying on higher repetition ranges with lower weight and force output. Unfortunately, you are not off the hook with respect to endurance type activities either, because all muscle types rely on glycolysis for energy production to some extent, it's just that the fast twitch fibers do so much more extensively than the slow twitch. And, sadly, again, you cannot train your way out this.
I do not have glycogen storage disease, but if did, I think that I would attempt to address it with a strict ketogenic diet, more akin to what is prescribed for severe epilepsy rather than the conventional "wrap everything in bacon" version. Basically, you want to eat extremely high fat, moderate protein, low carb. I think your ratios would be something along 70/20/10 at least. The basic idea is to avoid meals that require a compensatory glucagon release, which pretty much puts a limit on protein which is quite insulinogenic. High carbohydrate diets would be a problem because one of the primary disposal pathways, synthesis of glycogen in the liver and muscles is simply impossible ... people with glycogen storage disease simply cannot carbo load!
If you were eating a strict ketogenic diet, meal frequency would not be much of an issue for you.
Lastly, though, keep in mind that the incidence of this disease is fairly low, I think on the order of 1 in 25000 people has it. However, this low incidence rate may be due to inadequate diagnostic tests and or medical awareness. But again, that is more speculation on my part. You might want to run this by your doctor.
Hope you sort it out. If you do decide to go the ketogenic route, let us know how you make out.
-PK