I've always worn cross trainers before but I'm using them typically on the treadmill, eliptical, and walking outdoors. So I mentioned to the girl in the store that I've been having some numbness in my toes with my current shoes. She recommended I go up 1/2 a size and try a running shoe instead of a cross trainer. So thats what I did. Heres my questions.. 1) Now when I'm on the eliptical my calves are getting tired really easily, is it because of a different position that my feet may be in with the new shoes? Or should it be a concern? 2) I really feel like my feet are moving around a lot in the shoe and I'm getting a stretching sensation in my arch.. Any clues? Basically.. should I scrap these shoes because of these issues and try something else or chalk it up to a new fit/style and just make myself get used to them?