Just as with any other boots (or even a running shoe, for that matter), you'll want to give your feet and your new boots some time to get to know each other. You'd never take off on a long hike with a brand new pair of standard hiking boots and the same is true here. Of course, how long you need will depend upon the manufacturer and the individual. Some people will find their new barefoot hiking boots feel perfect from the first time they put them on.