The average man, when he is pressed to overwork, thinks that by cutting out some of his exercise and devoting the extra time to his work he can accomplish more. There never was a greater mistake; in the long run this method is the most expensive of all.
Nature never punished a man for getting his legs tired. She has punished many for getting their nerves exhausted.
Lack of activity destroys the good condition of every human being, while movement and methodical physical exercise save it and preserve it! — Plato