I have the same dress as Gnat, and I think I might have caused a few heart attacks when I wore it for a sprint session last Friday - the shorts that came with it are really short and as with all other shorts that are supposed to go only a few inches down my thigh it ended up in a nice little roll around my crotch. This looked rather interesting when sprinting I'm sure... But it's really comfy!

Warning though: do not leave cellphones in the pocket when sprinting, they fall out.