An athlete follows a very low-carbohydrate diet for a week and then performs a 30-second maximal sprint. Which performance outcome is most plausible and why?

• A. Performance will substantially improve because absence of dietary carbs forces immediate upregulation of protein synthesis that enhances sprint power.
• B. Performance becomes dependent exclusively on ketone bodies produced during low carbohydrate intake because muscles cannot use fatty acids under any circumstances for ATP.
• C. Performance likely decreases because short, maximal efforts rely heavily on stored muscle glycogen and readily available carbohydrate-derived ATP, which are depleted on low-carbohydrate diets.
• D. Performance will be unchanged because fats can be oxidized fast enough anaerobically to supply ATP for a 30-second sprint as efficiently as glycogen.

Answer: (C)