Mixed

Adapting to a ketogenic low carbohydrate, high fat (LCHF) diet during intensified training impairs exercise economy and negates performance improvements in elite endurance athletes, despite increasing peak aerobic capacity.

For elite endurance athletes, switching to a strict ketogenic diet during intense training blocks is likely counterproductive. While it may increase your ability to burn fat, it appears to make your body less efficient at using oxygen at race speeds, leading to no performance gain despite improved aerobic capacity. Stick to high-carbohydrate or periodized carbohydrate strategies for performance outcomes.