1.6.16-17 (Cambyses and his son Cyrus speaking; tr. Walter Miller):
"[T]ell me what means you adopt to keep well yourself."
 "In the first place, by Zeus," said Cyrus, "I try never to eat too much, for that is oppressive; and in the second place, I work off by exercise what I have eaten, for by so doing health seems more likely to endure and strength to accrue."
μνήσθητι σὺ πῶς πειρᾷ σαυτοῦ ἐπιμελεῖσθαι ὅπως ὑγιαίνῃς.
 καὶ ὁ Κῦρος εἶπε· πρῶτον μὲν νὴ Δία πειρῶμαι μηδέποτε ὑπερπίμπλασθαι· δύσφορον γάρ· ἔπειτα δὲ ἐκπονῶ τὰ εἰσιόντα· οὕτω γάρ μοι δοκεῖ ἥ τε ὑγίεια μᾶλλον παραμένειν καὶ ἰσχὺς προσγενέσθαι.