The problem with loose-fitting running shoes is that when your feet strike the ground, the cushion you’re expecting isn’t necessarily where you expect it to be. Your feet and leg muscles are priming themselves for a footstrike with a little flip to one side, but your shoes flop on impact instead. Over time all those misfires add up, and where they add up is often in your knees. Which is what makes the Zoom Elite 9 so great: At just 8.2 ounces, it’s an uptempo shoe with race-day fit, but enough cushion to keep your knees from feeling every inch of asphalt.