Originally Posted by
hamster
Aha. As I understand, they claim, roughly speaking, that ketones take precedence over blood glucose and they can be successful at muscle glycogen sparing even in situations where normal edible carbs fail. And they do mention that "The observed improvements in metabolic efficiency ... may translate to greater muscular work output for a given oxygen requirement during exercise" (the aforementioned 28%), though extrapolating from rat hearts to pro cyclists is a bit of a stretch. They work with a compound designed to metabolise into ketones in the bloodstream. One of the authors is a director of a startup that makes that compound.
Well, more than taking precedence as fuel (Peter Attia refers to ketones as "jet fuel") they apparently (read theoretically) preserve the endogenous intramuscular glycogen so that when the ketones run low or out, the glycogen can be used by the body - sprints, breakaways, etc. At first I dismissed the idea of the OP that their use could be labeled doping but now I'm not so sure. The derivativized ketones, allowing them to stay intact during transit through the body, are clearly artificial. Therefore taking these is tantamount to taking an orally bioavailable, performance enhancing drug. Hamster man? yes-no?