I recently bicycled 500 miles in colorado. The entire time I was at an altitude of between 6500' and 12,000'. With the Altitude training that I had completed with Dr. Rosen I was able to do the long (10-15 mile) climbs over the mountain passes with no breathing problems. In previous years of exertion at altitude I had problems catching my breath, but this time the 12000' passes felt easier and without that ""I can't catch my breath"" feeling. Dr. Rosen herself is just wonderful to work with, she was incredibly flexible with her schedule, very knowledgeable, and just a downright nice person. I would highly recommend talking with Dr. Rosen.