The shoe for training and the shoe for the actual race if they differ, if they are the same then just that shoe.
For me I'm not sure, still trying to find that perfect shoe. I was using the hoka clifton 1 for awhile but it's just a little too bulky for my tastes and I don't like the tongue, seems awkward and I want to try to pull it up more. I'm liking the new balance propel, would like to try out the beacon 2.