These are excellent drills that promote not only a good warm-up but also technique, coordination, plyometric movements, and neurological development. This might look simple or "silly" but actually it is very difficult to do (at least 15 to 20 minutes straight) This is like "child's" play, this is what children do when they are young as you get older you don't do this type of movements which are an important component in running efficiency. Here in the west, especially middle and long-distance runners don't do this and over a period of time (years) the running becomes not as "bouncy" Sprinters might do this type of training.
