Passage 6.23.2
χωρὶς μὲν δὴ ἐς ἅμιλλαν τῶν δρομέων ἐστὶν ἀποκεκριμένος δρόμος, ὀνομάζεται δὲ ὑπὸ τῶν ἐπιχωρίων ἱερός, χωρὶς δὲ ἔνθα ἐπὶ μελέτῃ δρομεῖς καὶ οἱ πένταθλοι θέουσιν. ἔστι δὲ ἐν τῷ γυμνασίῳ καλούμενον Πλέθριον· ἐν δὲ αὐτῷ συμβάλλουσιν οἱ Ἑλλανοδίκαι τοὺς καθʼ ἡλικίαν ἢ καὶ αὐτῷ διαφέροντας τῷ ἐπιτηδεύματι· συμβάλλουσι δὲ ἐπὶ πάλῃ.
There is a separate track specially set apart for contests among runners, which the locals call sacred, and another distinct area where runners and pentathletes practice their exercises. Within the Gymnasium is a place called the Plethrion; here the Hellanodikai pair competitors according to age or skill, matching them together for wrestling bouts.