Extremely lightweight, but what would you expect from a world class running shoe. Nothing less! The shoe runs a bit small for the size chart, so get at least one size larger than your regular shoe size. I was not happy to find that the nylon mesh material was/is not that durable. Don't drag or scuff the uppersthey will tear, and very easily. The bottoms are expected to lastup to six months, I'm told under heavy use. I'm not an avid runner, so no problems here. Good shoenot great, but good . . .  bgs.