LM. Burke and TD. Noakes (2026). Does a low-carbohydrate diet impede endurance sports performance? Debate Consensus. The American journal of clinical nutrition, 123(5), 101271. https://doi.org/10.1016/j.ajcnut.2026.101271

PubMed 42070893

[Abstract]
According to current scientific consensus, strategies that promote the availability of body carbohydrate (CHO) stores to meet the fuel needs of endurance sport represent the best approach to optimize performance. Such strategies are known to achieve a range of metabolic and nonmetabolic benefits during both high intensity exercise of short duration and more prolonged exercise of lower intensity. This debate considered a counter proposal to the concept that fat oxidation cannot supply ATP sufficiently rapidly to support performance in such events. Indeed, the "ketogenic low-CHO high-fat" diet can increase the athlete's capacity to oxidize the more plentiful body fat stores. Even here, however, CHO ingestion during exercise improves performance of prolonged events by preventing exercise-induced hypoglycemia. This debate sought to advance current understanding of the competing ideas that to maximize either their CHO or fat oxidation during exercise and so optimize their performance, endurance athletes should eat diets rich in either CHO or fat. Points of agreement include the muscle's capacity to be trained to increase oxidation of either fuel, whereas points of disagreement include whether strategies to promote highest rates of CHO oxidation provide advantages over the amounts needed to prevent hypoglycemia. Future research should target challenges in measuring both metabolism and performance.