Welcome to the world of altitude tents, considered by many to be the next frontier of training technology. For nearly 40 years, athletes have been experimenting with high altitude training; the notion of simply sleeping at a high altitude has been around for about 15 years. To achieve this, athletes can install tents in their bedrooms, thereby seamlessly integrating altitude training into their everyday lives. A long list of pros has been testing out the concept. By some accounts, 16 of the top 20 finishers of the 2005 Tour de France, all of the Americans tipped as hopes for the general classification at the 2006 Tour, and five of the top six finishers of the 2006 Tour use the tents as part of their training program.