Effect of Acute Ingestion of a Ketone Monoester on Psychomotor Vigilance During Acute Severe Hypoxia Exposure

Sixteen male participants completed a double-blind crossover study in which they took a psychomotor vigilance test in normoxia and then in simulated severe hypoxia (6,096 m, 9.7 percent O2) after ingesting either a ketone monoester at 650 mg/kg body mass or a taste-matched placebo. The ketone monoester raised blood R-beta-hydroxybutyrate above 3 mM and lowered blood glucose by about 20 mg/dL compared with placebo. Heart rate rose in hypoxia in both conditions, with no difference between conditions in that change.