Give me a few days and I will find you an answer. I will talk to my co-workers this week and see if any of them know or have an explanation.
I would say that the barometric pressure has no affect, for example 1012.1 hPa feels the same on your body regardless if you are 14000 ft up or if you are sitting in the bottom of the deepest cave. But O2 saturation will have an affect. There is a reason why elite athletes train at high levels.
Another option is to go to weathernetwork.ca and under interact go to communications and Ask The Expert
They will get you an answer.