adidas’ long standing collaboration with British designer Stella McCartney fuses sportswear and sustainability – as this training cap shows. Made from recycled polyester, the classic six-panel set-up is coloured in black and designed to keep your hair, sun and sweat out of your face when you’re on the move. It’s fitted with a handy and hidden zip pocket - so you can leave everything but your house key at home - and features a drawcord adjuster at the back to help customise the fit.