The hormone released during physical activity, often referred to as the "feel-good hormone," is endorphins. These neurotransmitters are produced by the body in response to stress, pain, or exercise and help to relieve discomfort while promoting an improved mood. Endorphins contribute to the phenomenon known as the "runner's high," offering feelings of euphoria and enhanced relaxation post-exercise. This effect encourages individuals to engage in regular physical activity, improving both physical and mental health due to the positive feelings associated with their workouts.