On, Hoka and other challengers are catching up fast.

The origin of On, a Swiss sportswear brand, is unusual. In 2010 Olivier Bernhard, a triathlete, stuck bits of garden hose to the bottom of his trainers for added cushioning. The idea worked so well that he and two friends decided to make a business out of it. Their shoes were a hit; last year the company made almost $2bn in sales.