How Exercise Promotes Positive Well-Being Exercise can also be used to enhance well-being in people who already feel mentally healthy. Increased physical activity has been found to enhance mood, improve energy levels, and promote quality sleep. There are several reasons why physical activity can be good for psychological well-being: Exercise decreases stress hormones. Exercise decreases stress hormones like cortisol. It also increases endorphins—your body's ‘feel-good’ chemic