MyAirAide to improve lung capacity?

What’s your opinion on MyAirAide?..www.MyAirAide.com

I’ve used it for about 4 long rides and thought I loved it…then I used it at a race over the weekend and felt very sluggish…could’ve been the heat though…

Thoughts/experiences?

Since you dont use 100% of the O2 you breathe in I wouldnt think stuffing more air in your lungs would do anything.

Anyone, Bueller, Bueller???

I am wondering if anyone has tried this. I got a coupon for it at a major bike ride here in Denver.