Ketone monoester intake attenuates exercise performance decline in normobaric hypoxia: A post-hoc subgroup analysis of 5 young male adults without acute mountain sickness

This post-hoc subgroup analysis included 5 young healthy men who completed both sessions of a 29-hour protocol at a simulated altitude of 4000 to 4500 m, with regular ketone ester (KE) or placebo intake, without developing severe acute mountain sickness. KE did not change peak power output during the first two maximal cycling tests, but increased it by 36 W during the combined maximal-submaximal test at 26.5 hours. KE increased blood oxygenation before all three tests and muscle oxygenation only before the combined test, while sleep and cognitive function were not affected.