"This is one of those fitness situations that evades basic definition: Started by Taryn Toomey, it's a self-titled cathartic experience, where you spend 75 minutes engaging in intense movement to “break open and activate ‘stagnant’ layers in the body.” In short you move, and scream, and shake, and yell as you release emotional energy–and get a pretty incredible workout in the process. It requires an open mind and a willing spirit. Photo Credit: Jaimie Baird"