These are used in middle distance events such as for example, running a 400 meters distance run. And these are the muscles. So type two B or FAS glycolytic are used in sprint events. So for example, if we're diving or sprinting, let's say 100 meters or swimming 50 meters, these are the muscles that are basically used. So let's discuss the fast glycolytic. So fast simply means these also have a fast contraction speed and that's because they break down ATP quickly.