Ketone Bodies Impact on Hypoxic CO₂ Retention Protocol During Exercise

Area of Science:

• Exercise Physiology
• Nutritional Biochemistry

Background:

• Exogenous ketone esters (KME) show promise for enhancing oxygen availability during hypoxia, potentially aiding high-altitude performance.
• Voluntary hypoventilation (VH) with exercise simulates hypoxic conditions by reducing oxygen and increasing carbon dioxide, without changing ambient pressure.

Purpose of the Study:

• To investigate the effects of KME on physiological and metabolic responses during simulated high-altitude exercise (VH).
• To determine if KME can mitigate carbon dioxide retention during VH exercise.

Main Methods:

• A double-blind, randomized crossover study involving 15 male distance runners.
• Participants performed submaximal exercise with VH after consuming either KME or a placebo (PLA).
• Measurements included blood gases, metabolites, oxygen saturation, cognition, and respiratory parameters.

Main Results:

• KME increased R-β-hydroxybutyrate and decreased blood glucose, without affecting lactate.
• VH exercise reduced blood (SpO2) and muscle (SmO2) oxygenation and impaired cognitive reaction time.
• KME significantly reduced carbon dioxide retention (PCO2) post-exercise and during recovery compared to placebo, independent of respiratory rate.

Conclusions:

• KME administration rapidly alters metabolism and acid-base balance.
• KME acts as a countermeasure to carbon dioxide retention during VH exercise.
• KME may offer a metabolic strategy to support performance under simulated high-altitude conditions.