You may have heard "healthy mind, healthy body" or the actual passage from Juvenal's Satire X, "orandum est ut sit mens sana in corpore sano." The message is that one needs to nourish not only one's mind or body, but the other one, as well. Plutarch, the famous biographer of the great men of Greece and Rome, wrote other treatises, including ones on morality. In his advice about keeping well, he includes a section on the proper way to train physically to be a scholar.

It includes instructions for both mind and body. Plutarch considers the voice the part of the body that most needs strength training and suggests an application of oil much like that used by athletes. A strigil, which was used with oil for cleansing, is shown on the vase above. The following passage appears in the 1928 Loeb edition, but is copied from Bill Thayer's site.

16 1 Let us now take up each topic anew once more; and in the first place, on the subject of exercises suitable for scholars, we beg to remark that one might follow the example of the man who, by saying that he had nothing to write for people dwelling by the sea on the subject of ships, showed clearly that they were in use; and so in the same way one might say that he was not writing for scholars on the subject of exercise. For it is wonderful what an exercise is the daily use of the voice in speaking aloud, conducing, not only to health, but also to strength — not the strength of the wrestler which lays on flesh and makes the exterior solid like the walls of a building, but a strength which engenders an all-pervasive vigour and a real energy in the most vital and dominant parts. That breathing gives strength the athletic trainers make clear in telling the athletes to brace themselves against the rubbing and stop their breath meantime, and keep tense the portions of the body that are being kneaded and massaged. Now the voice is a movement of the breath, and if it be given vigour, not in the throat, but, as it were, at its source in the lungs, it increases the warmth, tones down the blood, clears out every vein, opens every artery, and does not permit of any concretion or solidifying of superfluous fluid like a sediment to take place in the containing organs which take over and digest the food. For this reason we ought especially to make ourselves habituated and used to this exercise by continual speaking, or, if there be any suspicion that our body is not quite up to the mark or is somewhat fatigued, then by reading aloud or declaiming. For reading stands in the same relation to discussion as riding in a carriage to active exercise, and as though upon the vehicle of another's words it moves softly, and carries the voice gently this way and that. But discussion adds contention and vehemence, as the mind joins in the encounter along with the body. We must, however, be cautious about passionate and convulsive vociferations. For spasmodic expulsion and straining of the breath produces ruptures and sprains.

After reading or discussion, before going to walk, one should make use of rubbing with oil in a warm room to render the flesh supple, extending the massage so far as practicable to the inward parts, and gently equalizing the vital spirit and diffusing it into the extremities. Let the limits of the amount of this rubbing be what is agreeable to the senses and not discomforting. For the man who thus composes the inward disquiet and tension in his vital spirit manages the superfluous in his body without discomfort, and if unfavourable weather or some engagement prevent his going to walk, it does not matter, for Nature has received her proper due. Wherefore neither travelling nor stopping at an inn ought to be made an excuse for silence, nor even if everybody there deride one. For where it is not disgraceful to eat it is certainly not disgraceful to take exercise; nay, it is more disgraceful to feel timid and embarrassed before sailors, muleteers, and innkeepers, who do not deride the man who plays ball and goes through the movements of sparring alone, but the man who speaks, even though in his exercises he instruct, question, learn, and use his memory. Socrates said that for a man's movements in dancing a room that would accommodate seven persons at dinner was large enough to take exercise in, but for a man who takes his exercise through singing or speaking every place affords him adequate room for this exercise both when standing up and when lying down.

Also see what Seneca says is the way to train -- for the purpose of developing your character: Seneca on Healthy Mind, Healthy Body.