The high altitudes of Nepal, Machu Picchu, and Denver may naturally administer pulmonary resistance that conditions human lungs, and improves athletic endurance, but who wants to spend the time and money to travel there? More importantly, who wants to train amongst their smelly tribal peoples who don't speak English? This is the era of shortcuts. Steroids, spray tans, calf implants, and now a mask that simulates massive elevations all make sure that when you bust your ass during a workout, you get your GD payday.
Above 8,000 feet, decreases in pressure result in a decreased access to oxygen, causing people who live at high elevations to adapt, and function normally while breathing lower levels of air, and causing the rest of us to get nauseatingly winded like a fat kid running from the Rottweiler he tried to steal a steak from. Rogue Fitness' Elevation Training Mask uses filters to restrict oxygen intake in an analogous way, so the people of Florida can build the same diaphragmatic strength, and alveoli elasticity as the people of the Bolivian Andes. Imagine the economic boost the State of Florida would enjoy if 80% of its population suddenly had the stamina to go to the Cracker Barrel past 5 pm!
The training mask is popularly worn for endurance-based endeavors, such as running or cycling. Training with less oxygen for an extended period of time ultimately results in the power to push through for longer, and at a higher level of exertion, when oxygen levels increase upon mask removal. The mask is also appropriate for other types of workouts, including lifting, CrossFit, aerobics, and P90X. Obviously, it looks cool too. No one who sees you in it will think you're a terrorist, or a paranoid schizophrenic or anything. Actually, the people we polled agree there's nothing they'd rather encounter during a yoga class or trail run at dusk than a panting extremist in a gas mask.
On second thought, the potential for freaking people out could be a pleasant bonus. Maybe the 'roid-raging lugnuts at the gym will finally give you some space to lift. And that jackhole who walks on the treadmill at 2.3 mph yapping on his cell while you're waiting for a machine might be more inclined to finish up. And the guy whose eyes linger just a little too long on your ass in the locker room...gone.