Letters 15.2

This, then, is the sort of health you should primarily cultivate; the other kind of health comes second, and will involve little effort, if you wish to be well physically. It is indeed foolish, my dear Lucilius, and very unsuitable for a cultivated man, to work hard over developing the muscles and broadening the shoulders and strengthening the lungs. For although your heavy feeding produce good results and your sinews grow solid, you can never be a match, either in strength or in weight, for a first-class bull. Besides, by overloading the body with food you strangle the soul and render it less active. Accordingly, limit the flesh as much as possible, and allow free play to the spirit.

Seneca, Letters to Lucilius 15.2, translated by Richard Mott Gummere