Although changes have been shown in the shoe foam response, it is not easy to set limits to the peak pressures that rep-resent an increased risk of a foot injury. Previous bio-mechanical studies suggested a trainers’ life to be no more than 500 km [16], although no specific reason was given. Tests on the durability of outsoles [17] show that a life of 500 km is possible, due to excessive wear of edge of the heel.