The fact that the body, if left to itself, naturally wakes and sleeps on a twenty-five-hour cycle (known as the circadian rhythm) does not prevent us from waking and sleeping on a twenty-four-hour cycle without harm. On the other hand, studies of night-shift workers have demonstrated that their bodies never completely adjust to the reversal of the wake-sleep cycle.
Night workers suffer a higher incidence of colds and depression than day workers and tend to have chronically weakened immune systems.
What is fundamentally important about biorhythms, I believe, is that they provide the basis for the state of dynamic non-change. I used this phrase to describe the balance of opposites that must be maintained in order for the body to resist disorder. It is necessary that we think, feel, and move in balanced cycles.
If you decided to run a marathon and your body insisted on keeping to its “normal” levels of functioning, you would quickly collapse. A faster heartbeat, higher body temperature, and elevated blood pressure have to kick in for you to be able to run.
We are awash in a tide of balance and imbalance surging back and forth, dozens of bodily functions are disturbed every second, meaning that any fixed definition to health becomes meaningless. Food, water, and air flow through us in rhythmic patterns determined by dozens of variables, and residues of experience are built up like shifting sand dunes.
Structure and motion, the fixed and the changing, both count. Your doctor may tell you that you have a resting pulse of 80, blood pressure of 120/70, and body temperature of 98.6 degrees F, all of which are considered normal. Yet this assessment is purely for convenience. Such measurements are good only for the moment they are taken, for each dances around its balance point, creating the music of the living body.
Adapted from Ageless Body, Timeless Mind, by Deepak Chopra (Three Rivers Press, 1998).