These shoes came flawed.  As I live overseas, I decided to try to make them work.  But I can't make them work. I put a band aid inside the left forward section of the left shoe where the defect was sticking my foot with a plastic sliver.  The plastic sides are too inflexible and they cause soreness on the tops of both of my feet.  The heel pockets are too wide and and my heels slip up and down as I walk.  After a hour walking on a path my feet hurt.  After a half hour on a treadmill, my feet hurt.  I think replacing the stiff plastic sides with leather or fabric would do a lot to make them more comfortable.  I do not intend to wear them again.  Exercise shouldn't be tortuous.  Wearing these shoes is torture!