Speed comes from Oral balance, posture of the Head,Chin down more than 15% alters the noeromuscular system adapting. Throws everything out of balance and slows response. A great way to observe this is watching Sprinters. As regars the Head band it keeps the Head where it should be, the head supporting its self stops the shoulders from tightening and not giving them a response, which doesnt have to be changed saving time and energy.