It is important to select the correct size of skates as you don’t want to waste or lose energy from unnecessary movement inside the skate
Bigger size skates aren’t a good idea, as you want a minimal amount of empty space inside your skates. If your feet have too much space to move around inside the skate, you waste a lot energy (as all the movement and energy is wasted inside the skate), you want all the movement your feet make inside your skate to be transferred on to the blade. This can’t be done properly with the wrong size skates.