20.500.12556/RUL-185594 Ketone ester ingestion impairs exercise performance without impacting cognitive function or circulating EPO during acute hypoxic exposure Altitude-induced hypoxemia impairs exercise performance and cognition. Interestingly, ketone ester (KE) ingestion may attenuate hypoxemia, which likely explains the observation that KE impairs high-intensity exercise performance in normoxia but not in hypoxia. Moreover, KE was reported to attenuate cognitive decline at extreme altitudes (~6,100 m). Given that hypoxemia is unaffected by KE in milder conditions, the impact of KE on cognition and performance in the absence of elevated oxygenation remains unknown. As KE may increase postexercise circulating [erythropoietin] ([EPO]) at sea level, we also assessed if KE might augment the blood [EPO] response after hypoxic exercise. In a double-blind, cross-over design, 13 healthy, male participants completed two 5.5-h sessions at 4,000-m simulated altitude while receiving either KE or placebo (CON). Throughout a graded exercise test (EX $_{MAX}$) after 1.5 h, and a submaximal exercise bout (EX $_{SUBMAX}$) after 3 h, blood and tissue oxygenation, ventilatory parameters, and acid-base balance were evaluated. Other measurements included cognitive function and blood [EPO]. KE reduced power output achieved during EX $_{MAX}$ by 3.6%, whereas blood and cerebral oxygenation were similar. KE ingestion lowered blood pH, [HCO$_3$], pCO $_2$, and [glucose], but did not impact cognitive function. In both KE and CON, circulating [EPO] increased by ~56% after 5 h. These results indicate that KE ingestion impairs high-intensity exercise performance, at least if not compensated by elevated oxygenation. A progressively increasing oxygenation upon KE was unable to protect against hypoxia-induced cognitive declines and potentially counteracted a KE-induced augmentation of circulating [EPO]. sport altitude cognition erythropoietin (EPO) exercise performance hypoxia ketones šport nadmorska višina višinske prilagoditve kognitivne funkcije eritropoetin (EPO) hipoksija hipoksična izpostavljenost ketoni true false true Angleški jezik Slovenski jezik Članek v reviji 2026-08-11 14:43:02 2026-08-11 14:43:03 2026-08-12 04:03:49 0000-00-00 00:00:00 2025 0 0 Str. 1309-1320 iss. 6 Vol. 138 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 796.01 1522-1601 10.1152/japplphysiol.00097.2025 236890371 stalmans-et-al-2025-ketone-ester-ingestion-impairs-exercise-performance-without-impacting-cognitive-function-or.pdf stalmans-et-al-2025-ketone-ester-ingestion-impairs-exercise-performance-without-impacting-cognitive-function-or.pdf 1 5DCD6FEAA51E6D0524C0D3479E653B46 d837fc70da48ab6615e5f48b4b28ce52a699b414002c49a3d6321de03deddc2b 55325e85-9586-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244287 https://journals.physiology.org/doi/full/10.1152/japplphysiol.00097.2025 0 ddbcf0d3-9585-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244286 Fakulteta za šport 0 0 0