As you are probably aware there are a number of physiological tests for supplements and foods: Coco and Pulse to name two.
Do you know of any correspondence between these procedures?
And off subject: In my slow raising of oygenation using Buteyko I exercise using nose breathing alone. I use the inclination to mouth breathe as an indication of excessive energy expenditure relative to oxygen supply. What appears to be happening is the "mouth breathing threshold" is rising. is this the correct process? Do you know of any research which may have been done on this subject and its correspondence to VO2 Max?