Because long after parkour and buildering have gone out of fashion there will be nice sweaters.
Check the latest from James at: http://sploid.gizmodo.com/watch-this-guy-perform-a-massive-leap-and-hang-490-feet-1582583737
His website (many sweaters!): http://jameskingston.co.uk/
Margaret Howell makes some nice sweaters: http://www.margarethowell.co.uk/men-ss14/knitwear
Full disclosure: buildering.net receives shit all from Margaret Howell, but I personally think their sweaters are made from baby unicorn fur. So soft.