FIGURE 1.

Schematic diagram of the experiment to investigate whether acute ingestion of (R)‐3‐hydroxybutyl (R)‐3‐hydroxybutyrate (R‐BD R‐βHB) ketone monoester (KME) impacts cognitive performance and oxygen saturation ($S_{\mathrm{p}{\mathrm{O}}_2}$) at rest and during moderate‐ to vigorous‐intensity exercise in the form of a weighted treadmill ruck during rapid‐onset acute hypoxic exposure. Abbreviations: GI/AMS, Gastrointestinal & Acute Mountain Sickness Questionnaire; HR/HRV, Heart Rate and Heart Rate Variability; KME, Ketone Monoester; PLA, Placebo; R1, Ruck 1; R2, Ruck 2; RPE, Rated Perceived Exertion; SpO2, Oxygen Satuation.