Karageorghis is looking for a power song—one that resonates so strongly that it alters the athlete’s mood and physiology. He can often tell right away when he’s hit on an effective track. “You immediately observe a rhythm response,” he says. The athlete starts bobbing his head or tapping her toes. There are also the telltale signs of physiological arousal, such as dilated pupils and piloerection, when the hair on your skin stands on end. This is how Karageorghis knows the song is triggering an adrenaline rush.
