Carbohydrate mouth-rinsing does not rescue simulated time trial performance in trained endurance cyclists following a 5-day ketogenic diet

The data indicate that repeated 6.4% CHO-MR during endurance cycling is insufficient to overcome performance impairments induced via a 5-day ketogenic diet. This suggests that peripheral substrate availability may constrain the hepatic glucose output in response to central nervous system cues. Further research is required to elucidate how peripheral glycogen stores, central neural drive, and ergogenic interventions interact under low-carbohydrate conditions.