Stillness Is the Key by Ryan Holiday

champion Kerri Walsh Jennings has said makes her such a killer on
the court.
Some ancient traditions have held that the soul is in the belly,
which is fitting for two reasons. Because we’ve just been through the
belly of the beast part of our journey, and because it sets up where
we go next.
Stillness isn’t merely an abstraction—something we only think
about or feel. It’s also real. It’s in our bodies. Seneca warned us not to
“suppose that the soul is at peace when the body is still.” Vice versa.
Lao Tzu said that “movement is the foundation of stillness.”
What follows then is the final domain of stillness. The literal form
that our form takes in the course of day-to-day life. Our bodies
(where, you must not forget, the heart and the brain are both
located). The environment we put those bodies in. The habits and
routines to which we subject that body.
A body that is overworked or abused is not only actually not still,
it creates turbulence that ripples through the rest of our lives. A mind
that is overtaxed and ill-treated is susceptible to vice and corruption.
A spoiled, lazy existence is the manifestation of spiritual emptiness.
We can be active, we can be on the move, and still be still. Indeed, we
have to be active for the stillness to have any meaning.
Life is hard. Fortune is fickle. We can’t afford to be weak. We
can’t afford to be fragile. We must strengthen our bodies as the
physical vessel for our minds and spirit, subject to the capriciousness
of the physical world.
Which is why we now move on to this final domain of stillness—
the body—and its place in the real world. In real life.