If elite male cyclists eat a super high-fat diet for six days and then carb-load for one day, they’ll perform worse in sprints—even though they don’t feel more tired, their heart rate doesn’t change, and their muscles fire the same way.

If elite male cyclists eat a super high-fat diet for 6 days before carb-loading for a day, they’ll feel just as fast over a long 100-km ride — but they’ll have less power for short, intense sprints compared to when they eat a high-carb diet first.

If a male cyclist eats a super high-fat diet for 6 days and then loads up on carbs for 1 day, it won’t slow them down in a 100-km race compared to eating lots of carbs all along.

If male cyclists eat a super high-fat diet for six days, their body's 'fight or flight' system might get a bit more active — and that change doesn’t go away right after they start eating carbs again.

If elite male cyclists eat a super high-fat diet for six days, their bodies get better at burning fat for fuel — even when they switch back to eating lots of carbs for a day.

Whether you eat carbs, protein, or nothing before a hard cycling workout with short bursts of maximum effort, your power output stays the same — your body can still push hard regardless of what you ate beforehand.