Asencio responded like most people, the chemistry of his blood literally changed so that it would be able to coagulate more easily. At the same time, his blood vessels constricted so that he would bleed less if he got hurt. His blood pressure and his heart rate shot up. And a slew of hormones—in particular cortisol and adrenaline—surged through his system, giving his gross-motor muscles a sort of bionic boost. (The hormones are so powerful that, after a life-or-death situation, many people report having an odd, chemical taste in their mouths.)
