A pre-competition glycogen depletion training block, where a significant amount of medium intensity training is logged in a fasted&#x2F;glycogen depleted state, followed by a glycogen load immediately prior to competition is the gold standard in terms of competition preparation for sports that need a mix of aerobic and anaerobic endurance.<p>As for athletes that get the majority of their surplus calories from carbs rather than fat, look up various world champions and google their diet:<p>* Sprinters
* Rowers
* In-season bodybuilders
* Powerlifters cutting weight for competition
* Mixed martial artists<p>There is a bit of movement towards paleo eating in the MMA community (though oats, potatoes, rice and dairy are still typically consumed) and offseason bodybuilders&#x2F;powerlifters will frequently eat a balanced mix of carbs and fat.  Almost nobody at the top levels does low carb&#x2F;high fat though.