Herzogenaurach, Germany - Granules of foamed thermoplastic polyurethane (TPU) are central to adidas's new 'Boost' running-shoe technology, launched in New York, 13 Feb 2013.
adidas claims the new technology offers "a new way to run" with this foam, which the footwear giant's Eric Liedtke, head of Sport Performance, says, "provides the highest energy return in any running product."
According to Liedtke, "Everyone wants more energy … whether you're running a marathon, training for an upcoming season or just trying to get back in shape."
adidas says Boost combines seemingly contradictory performance benefits: soft cushioning and responsiveness.
"… energy is the secret weapon that can set you apart from the competition. An added boost of energy is what allows you to push yourself ahead of everyone else to cross that finish line first, especially in a sprint when every millisecond counts," said Yohan Blake, the current 100-m World Champion, who joined adidas at the launch of the Energy Boost running shoe.
The cushioning material is based on a BASF development: solid granular TPU is foamed, forming a cellular structure. adidas describes this as "thousands of small energy capsules which make up the footwear's distinctive midsole."
Tests on the TPU foam showed that, when taken from +40° to -20°C, it is three times more temperature-resistant than standard EVA material, providing a more consistent run. EVA (ethylene vinyl acetate) foam is the material commonly used as the midsole in running shoes.
Not only the midsole, but the upper on the new Energy Boost shoe also features PU - in the form of adidas Techfit technology with durable, elastic polyurethane, which adidas says provides "optimal comfort and support to the entire foot while in motion."
Here, a stretch, breathable mesh offers good fit -- like a sock -- while "engineered powerbands" across the upper give support to stabilise the foot when moving, says adidas.