Originally Posted by
Hermes
In the ketosis example, what happens when there is no or little glycogen and the ATP CP cycle is over and full muscle contraction required? What is the mechanism and the byproduct? How does fat get converted to ATP in the absence of oxygen? I would like to see an energy balance and biochemical chart on this. Even though converting glycogen to ATP requires more oxygen, maybe more ATP is made per unit of O2 with glycogen than with fat. An energy balance will show that.
I don't know the details, but all the studies I have seen indicate that, while sub-maximal performance can be OK on a ketogenic diet, your top-end (VO2Max and above) performance is significantly less. A ketogenic diet may be useful for something but it isn't something you would use if you were racing or were concerned with performance.
It may be a bit of a misconception that you have no glycogen in your muscles on a ketogenic diet. Studies have found that on a ketogenic diet one has roughly half the muscle glycogen stores at the beginning of an exercise session but the body also adapts and ends up burning proportionately more fat during exercise. Glycogen still gets produced on a ketogenic diet through a different mechanism than when you consume carbohydrates.