I just read this and it made me laugh: “Where do you get your energy from?”.
The best bit: : “Fat is the body’s preferred and most reliable form of energy, which is why we store excess energy as fat on our bodies. Unless you think we accumulate body fat just to make pants fit tighter.” LOL
Fuelling from fat seems perfectly possible for events that are either short enough to be fuelled straight from glycogen (explosive sports and aerobic activities below, say, 60 minute duration, everything from crossfit to a 40km TT) or so long that the rate of calorie usage is low enough to come from fat burning - IM, ultrarunning, other self-paced endurance efforts.
What I don't understand, and haven't seen many examples of, is people using fat as a primary fuel source for events that fall between these two - a 2 or 3 hour road race for instance which requires the ability to ride way above fat burning exertion for significant portions of time. The glycogen you start with will not be enough to fuel the total effort and fat, even from a well trained fat burning metabolism, cannot supply the energy fast enough to sustain the intensity.
So, is being paleo something a racing cyclist can only do between races? For me it seems so.