Mind-Body Relationship
And the underlying assumption of the relationship between physical activity and mental health is really that we cannot separate the mind from the body, that the mind and body have a very intimate relationship and they don't operate as independent units; in fact, they're very closely integrated. And so, interestingly, this is not a new idea. The Greeks subscribed to the saying of mens sana in corpore sana, "in a sound mind is a sound body," and so for a long time, people have been thinking about the connection between mind and body, and in ancient Greek, regular physical activity was encouraged for both mental and physical health.