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. So the sympathetic nervous system shuts down these processes. It decreases their rate. So the overall effect of our sympathetic nervous system is to basically increase the blood flow to our heart, to our cardiac muscle, as well as to our skeletal muscle.