The Spira running shoe is a controversial running shoe because they have been banned by the International Association of Athletics Federations (IAAAF) as well as many national associations. This means that they can’t be used and so are prohibited from every running events held under their regulations.  The Spira running shoe has been banned as it as a recoil technology in the heel of the shoe that is supposed help prevent injury in runners. However the recoil technology also enhances performance, giving the runner wearing them an alleged unfair advantage.

To overcome this ban the Spira company have offered a million US dollars to anyone who can win a race using the shoe. The runners faces a ban by the IAAF if they do so. So far, two runners have collected the million dollars.

The Spira Striker is the flagship shoe from the company. The WaveSpring technology in the heel is designed to help transfer energy forward. It is assisted by a viscoelastic heel unit and an elastic forefoot. This allows for a very smooth ride when running, but the ride is also very stable. It is often hard for a running shoe to get the combination between stability and cushioning right, but the unique recoil or WaveSpring technology in this shoe allows this. There are also independent springs in the forefoot the allow for forefoot flexibility, but also are optimized for the energy needed during push off. The shoe also has a high level of durability. Other shoes in the Spira range include the Genesis, the Paseo, the Del Sol and the Volare