Has anyone tried this? Where did you get info on it

I am going to get set up. I have an O2 concentrator (it's a bit low @ 5) and a mask

I will make a stationary roller bike stand for the ride. This way my wife and I can use our bikes and still easily take them out for a ride.

I'm an inveterate researcher and hadn't heard of EWOT before. So I hit the google machine. Guess what? The only websites that talk about EWOT are selling EWOT. There are no peer reviewed journal articles investigating EWOT either for training or rehab. None.

The only sensible link I could find discussing it is here:
Exercise With Oxygen Therapy: Triathlon Forum: Slowtwitch Forums

I have a pulse oximeter and, going as hard as I can, I can't get it below 99% saturation at sea level. More O2 is not going to make any difference. At 10,000', I have trouble getting it below 97% and I live at sea level.

IDK anything about EWOT, but more O2 does make a difference. That's the point and benefit of EPO. It allows the blood to carry more O2. Saturation is the percentage compared to the max the blood can carry. But if the max is higher, then there's more at the same level of saturation.

The T in EWOT seems to stand for Therapy, not Training. So, if someone is selling something, I guess it seems to be some kind of (unproven) therapeutic effect, not an unproven training benefit.

Thanks carbonfibreboy. Your link supplied me with the German study that I had read about.
Oxygen Multistep Therapy: Physiological and Technical Foundations - Manfred Von Ardenne - Google Books

Also some interesting chatter about it.

I am a gadget guy and a pulse oximeter is on my list BTW.

Igualmente, You're right, my mistake, it is therapy. I read about this from someone who is not selling it.

For the record I am not doing this to train for competition. I could not find any other spots on the site to post it so this seemed like the best bet. My goal is to maintain fitness for my wife and I. In the winter we have a lot of days when it is just raining 2 much and she is not crazy about getting drenched and doing damage to her Pinarello. We do lots of other things daily and since we are in kissing distance of 70 we are not ready for a walker.

There's the rub. Our atmosphere is about 21% oxygen. At that concentration any healthy athlete's hemoglobin (the part of the blood that carries oxygen) is about 98-100% saturated even under intense training. Your blood simply cannot carry more. Even at threshold, you only use about 1/3 to 1/2 of the oxygen you are taking in as the air you exhale is still 12 to 14% oxygen. Breathing in a higher concentration of oxygen when your hemoglobin is saturated to 99+% just means that you will be exhaling all that extra O2. The only way to carry more O2 is to increase the amount of hemoglobin in the blood, not just breathing a higher concentration of O2. Even with very high hemoglobin levels (which has health risks including impaired circulation and clotting abnormalities) an athlete's muscle cells can only use so much oxygen, the rest is just recirculated. Once you get outside of the high normal range for hemoglobin, the risks outweigh the benefits rapidly.

Many people have the mistaken idea that you breathe harder during exercise because you need more oxygen. In reality, the primary respiratory drive is based on signals from chemoreceptors that measure the slight decrease in pH and increase in CO2 from the increased metabolism that comes with exercise. The body does have a back-up drive (the hypoxic drive) that is oxygen based, but it only comes into play in individuals who have respiratory compromise, like COPD, in which their CO2 levels are chronically high. The problem in a healthy athlete isn't getting more O2 in, it's getting CO2 out.

If you really think about it, exercising with supplemental oxygen is back asswards. To increase hemoglobin naturally, athletes train in an oxygen deprived environment such as training at altitude. Because there is less O2 available in the atmosphere, the body compensates by producing more hemoglobin (getting acclimated to high altitude). While I don't know of any research to back it up, it is a reasonable hypothesis that exercising in an oxygen rich environment would decrease the amount of hemoglobin the body needs which could actually impair performance once you return to a 21% oxygen environment.

^+1. This is correct. Just gotta do the work. There are no shortcuts. Even EPO doesn't make much difference without training.