How lucky you are to have this terrific added exposure. You should put some displays in the doorway with fun items for parade goers. Make them impulse buys--inexpensive, of course--and as customers bring these to the register, they'll get a good look at your merchandise.

You could also have a costumed character or two in the entrance of your store. Make the costume tie in with your store--such as a superhero or mythological character who runs very fast in . . . (you guessed it) great running shoes. 

You can bring kids and their parents into the store by having a costume contest before the parade. This will take some advance marketing and publicity, but the exposure will be well worth it.

Have fun!