The weakest among us can become some kind of athlete, but only the strongest can survive as spectators. Only the hardiest can withstand the perils of inertia, inactivity, and immobility. Only the most resilient can cope with the squandering of time, the deterioration in fitness, the loss of creativity, the frustration of emotions, and the dulling of moral sense that can afflict the dedicated spectator. Physiologists have suggested that only those who can pass the most rigorous physical examination can safely follow the sedentary life. Man was not made to remain at rest.
Inactivity is completely unnatural to the body.
And what follows is a breakdown of the body's equilibrium. When the beneficial effects of activity on the heart and circulation and indeed on all the body's systems are absent, everything measurable begins to go awry. Up goes the girth of the waist and the body weight. Up goes blood pressure and heart rate. Up goes cholesterol and triglycerides.