Ketone monoester reduces blood glucose, exogenous CHO oxidation, and oxidation efficiency in trained male cyclists when fed 120 g/h of CHO during exercise

To promote exercise performance, endurance athletes frequently consume CHO during exercise at ingestion rates of 90–120 g·h −1 . Here, we report for the first time that coingestion of a ketone monoester before and during prolonged cycling reduces blood glucose concentrations, exogenous CHO oxidation, and oxidation efficiency compared with CHO alone (120 g·h −1 ; 1:0.8 ratio of maltodextrin and fructose). Ketone monoester ingestion also increased plasma abundance of metabolites associated with carbohydrate metabolism (glucaric acid) and protein turnover (3-methylhistidine).