Our brains change as we age, and adults lose up to 13 percent of the dopamine receptors in the reward system with each passing decade. This loss leads to less enjoyment of everyday pleasures, but physical activity can prevent the decline. Compared to their inactive peers, active older adults have reward systems that more closely resemble those of individuals who are decades younger. This may be one reason exercise is so strongly linked to happiness and a reduced risk of depression as we get older. It may also explain why people who eschewed exercise earlier in life find themselves drawn to it
...more
