Plutarch's Rules for the Preservation of Health (16-17)

ZEUXIPPUS. But we shall begin and treat of each of these, and first we shall discourse of those exercises which are proper for a scholar. And as he that said he should prescribe nothing for the teeth to them that dwelt by the seaside taught them the benefit of the sea-water, so one would think that there was no need of writing to scholars concerning exercise. For it is wonderful what an exercise the daily use of speech is, not only as to health but even to strength. I mean not fleshly and athletic health, or such as makes one’s external parts firm, like the outside of a house, but such as gives a right tone and inward vigor to the vital and noble parts. And that the vital spirit increases strength is made plain by them who anointed the wrestlers, who commanded them, when their limbs were rubbed, to withstand such frictions in some sort, in holding their wind, observing carefully those parts of the body which were smeared and rubbed.[*] Now the voice, being a motion of the spirit, not superficially but firmly seated in the bowels, as it were in a fountain, increases the heat, thins the blood, purges every vein, opens all the arteries, neither does it permit the coagulation or condensation of any superfluous humor, which would settle like dregs in those vessels which receive and work our nourishment. Wherefore we ought by much speaking to accustom ourselves to this exercise, and make it familiar to us; and if we suspect that our bodies are weaker or more tired than ordinary, by reading or reciting. For what riding in a coach is compared with bodily exercise, that is reading compared with disputing, if you carry your voice softly and low, as it were in the chariot of another man’s words. For disputes bring with them a vehemence and contention, adding the labor of the mind to that of the body. All passionate noise, and such as would force our lungs, ought to be avoided; for irregular and violent strains of our voice may break something within us, or bring us into convulsions. But when a student has either read or disputed, before he walks abroad, he ought to make use of a gentle and tepid friction, to open the pores of his body, as much as is possible, even to his very bowels, that so his spirits may gently and quietly diffuse themselves to the extreme parts of his body. The bounds that this friction ought not to exceed are, that it be done no longer than it is pleasant to our sense and without pain. For he that so allays the disturbance which is within himself and the agitation of his spirits will not be troubled by that superfluity which remains in him; and if it be unseasonable for to walk, or if his business hinder him, it is no great matter; for nature has already received satisfaction. Whether one be at sea or in a public inn, it is not necessary that he should be silent, though all the company laugh at him. For where it is no shame to eat, it is certainly no shame to exercise yourself; but it is worse to stand in awe of and be troubled with seamen, carriers, and innkeepers, that laugh at you not because you play at ball or fight a shadow, but because in your discourse you exercise yourself by teaching others, or by enquiring and learning something yourself, or else by calling to mind something. For Socrates said, he that uses the exercise of dancing had need have a room big enough to hold seven beds; but he that makes either singing or discourse his exercise may do it either standing or lying in any place. But this one thing we must observe, that when we are conscious to ourselves that we are too full, or have been concerned with Venus, or labored hard, we do not too much strain our voice, as so many rhetoricians and readers in philosophy do, some of whom out of glory and ambition, some for reward or private contentions, have forced themselves beyond what has been convenient. Our Niger, when he was teaching philosophy in Galatia, by chance swallowed the bone of a fish; but a stranger coming to teach in his place, Niger, fearing he might run away with his repute, continued to read his lectures, though the bone still stuck in his throat; from whence a great and hard inflammation arising, he, being unable to undergo the pain, permitted a deep incision to be made, by which wound the bone was taken out; but the wound growing worse, and rheum falling upon it, it killed him. But this may be mentioned hereafter in its proper place.

ZEUXIPPUS. After exercise to use a cold bath is boyish, and has more ostentation in it than health; for though it may seem to harden our bodies and make them not so subject to outward accidents, yet it does more prejudice to the inward parts, by hindering transpiration, fixing the rumors, and condensing those vapors which love freedom and transpiration. Besides, necessity will force those who use cold baths into that exact and accurate way of diet they would so much avoid, and make them take care they be not in the least extravagant, for every such error is sure to receive a bitter reproof. But a warm bath is much more pardonable, for it does not so much destroy our natural vigor and strength as it does conduce to our health, laying a soft and easy foundation for concoction, preparing those things for digestion which are not easily digested without any pain (if they be not very crude and deep lodged), and fleeing us from all inward weariness. But when we do sensibly perceive our bodies to be indifferent well, or as they ought to be, we should omit bathing, and anoint ourselves by the fire; which is better if the body stand in need of heat, for it dispenses a warmth throughout. But we should make use of the sun more or less, as the temper of the air permits. So much may suffice to have been said concerning exercises.