Ketone ester ingestion impairs exercise performance without impacting cognitive function or circulating EPO during...

Area of Science:

• Exercise Physiology
• Nutritional Biochemistry
• Altitude Medicine

Background:

• Altitude-induced hypoxemia negatively impacts exercise performance and cognitive function.
• Ketone esters (KE) may mitigate hypoxemia and cognitive decline at extreme altitudes.
• The effect of KE on cognition and performance in milder hypoxia, without improved oxygenation, is unknown.

Purpose of the Study:

• To investigate the impact of KE on exercise performance and cognitive function in simulated moderate-altitude hypoxia.
• To assess if KE influences circulating erythropoietin (EPO) levels following hypoxic exercise.

Main Methods:

• Double-blind, cross-over study with 13 healthy males at 4,000m simulated altitude.
• Participants ingested KE or placebo (CON) during two 5.5-hour sessions.
• Evaluated exercise performance (EX_MAX, EX_SUBMAX), cognitive function, blood gases, oxygenation, and circulating EPO.

Main Results:

• KE ingestion reduced peak exercise power output by 3.6% without altering blood or cerebral oxygenation.
• KE ingestion led to lower blood pH, bicarbonate, pCO₂, and glucose levels.
• Cognitive function was not affected by KE; circulating EPO increased similarly in both KE and CON groups post-exercise.

Conclusions:

• KE impairs high-intensity exercise performance in hypoxia when hypoxemia is not alleviated.
• KE does not protect against hypoxia-induced cognitive decline, even with progressive oxygenation.
• KE fails to augment the exercise-induced increase in circulating EPO during hypoxic exposure.