And to keep our temperature of the body at the same temperature, we have to expel that energy. And we do that by the process of sweating. Now, when we're running, we don't have to worry about digestion. We don't want to have to worry about digestion because our body basically needs to use the majority of the energy to basically run instead of digest. And so what happens is that decreases our digestive rate and at the same time, it inhibits peristalsis because parastosis is the movement of our food products through our small intestine for the process of absorption. So when we essentially begin to run, we don't want to worry about digestion or peristalsis.