Breathing concentrated oxygen under raised pressure sharply increases the oxygen carried dissolved in blood plasma (Henry's Law), letting oxygen reach tissue independently of red blood cells — a 2021 review describes an increase in oxygen diffusion into circulation of more than tenfold.
MechanismOrtega et al., Medicina (Kaunas), 2021
What this does not show
This is physics and physiology, not a clinical benefit. More dissolved oxygen is not, by itself, evidence that anyone feels or functions better.
Read the source (PMID 34577787)

