Wearing the Elevation Mask may seem weird (especially version 1.0 shown above) but you can make your workout harder than you can imagine. It simulates breathing at high altitudes by restricting the amount of air you can breathe in, which is supposed to make your lungs work very hard. A number of professional MMA fighters swear by it including Sean Sherk and Anderson Silva. The idea is that if the training is hard, the fight will be easy. There is no scientific evidence yet that confirms that working out with an altitude training mask can improve performance but if you're looking for a challenge, it may be worth a shot. There's a version 2.0 but some feel that version 1.0 is better.