Without the presence of catecholamines your body is naturally filled with endorphins, nature's "love drug" and natural pain reliever. When endorphins are released, your muscles are relaxed and there is a feeling of well-being and safety. Catecholamine release is a fear-based response, creating constriction in the muscles that is generally associated with pain. What's most interesting about catecholamines and endorphins is that they don't simultaneously exist. However, they are both always present--one will always be more dominant. The goal therefore is to "turn off" catecholamines and "turn on" endorphins.