There has been a lot of hype surrounding the Yeezy Boost, however, one of the most innovative aspects of the shoe has remained under the radar. All Adidas Boost shoes contain Infinergy, a midsole material created by Germany-based BASF, a chemical company with a footwear division.
Infinergy originated when Adidas requested a special material from BASF for their Boost line, which launched in 2013. The company was looking for a lightweight material that possessed both high resilience and soft cushioning, as the soles of running sneakers often thin out over time. “Infinergy really helped to transform Adidas from a lifestyle brand into a performance brand,” said Chau Nguyen, BASF’s footwear market segment manager.
As sneaker companies continue to market innovation, midsoles have been left out of new development. Nguyen pointed out that for the last 20 to 30 years, most sneakers have been made with EVA (ethylene-vinyl acetate) midsoles, a material that leaves room for improvement.
One of EVA’s faults is an attribute called compression set, meaning that when a material takes a load, it flattens out and doesn’t rebound. Therefore, when BASF was developing a new material, energy return was one of the key areas on which they focused. Infinergy dampens the shock impact and bounces the foot back for a rebound effect. The material achieves a rebound of 55 percent, unprecedented in comparable particle foams.
BASF has now provided a new choice in a market dominated by one material. “When an alternative material comes out, it’s a game changer,” Nguyen said.
Besides energy return, the other main qualities of Infinergy are comfort and durability. These qualities derive from the composition of the material, a closed-cell elastic particle foam that combines the advantages of TPU with those of foams. Inside the foam are tiny plastic cells with enclosed air bubbles.
Last year, Boost shoes proved their efficacy in performance with a series of marathon wins. In 2014, the men’s and women’s New York City Marathon winners and the men’s Berlin Marathon winner were all wearing Adizero Adidas Boost shoes.
In addition to the running line, Adidas is using Infinergy in a variety of other athletic categories including hiking shoes, snowboarding and golf shoes. It is also being used in lifestyle shoes including the Ultra Boost and a collaboration with Marvel’s Avengers for both children and adults. The material is exclusive to Adidas through 2017.