The above graph is reprinted from Perry et.al the authors conclude
“The data showed that a higher power output was required to maintain heart rate during hyperoxic training. This increased training intensity during hyperoxic resulted in improved exercise performance whereas cycling at 90% VO2max in room air and may be due to peripheral factors because cardiorespiratory responses were similar.”
Further worth noting is that the normoxic group plateaus out after 4 weeks while the hyperoxic group continues to develop. As most exercise physiology studies are conducted on college students any structured training regimen would lift their performance considerably. An elite athlete is already close to peak and only extraordinary stimulus would be able to increase performance. This is where oxelerate comes in.
Perry C G,Reid J, PerryW, Wilson BA. Effects of hyperoxic training on performance and cardiorespiratory response to exercise. Med Sci Sports Exerc.2005 Jul;37(7):1175-9.