Passage 5.8.9
τὰ δὲ ἐπὶ τοῖς παισὶν ἐς μὲν τῶν παλαιοτέρων οὐδεμίαν ἥκει μνήμην, αὐτοὶ δὲ ἀρέσαν σφίσι κατεστήσαντο Ἠλεῖοι. δρόμου μὲν δὴ καὶ πάλης ἐτέθη παισὶν ἆθλα ἐπὶ τῆς ἑβδόμης καὶ τριακοστῆς Ὀλυμπιάδος, καὶ Ἱπποσθένης Λακεδαιμόνιος πάλην, Πολυνείκης δὲ τὸν δρόμον ἐνίκησεν Ἠλεῖος. πρώτῃ δὲ ἐπὶ ταῖς τεσσαράκοντα Ὀλυμπιάδι πύκτας ἐσεκάλεσαν παῖδας, καὶ περιῆν τῶν ἐσελθόντων Συβαρίτης Φιλύτας.
Regarding the contests for boys, no tradition reaches back into the more ancient times, but the Eleans themselves established them according to their preference. Prizes for running and wrestling for boys were first introduced during the thirty-seventh Olympiad; Hipposthenes of Sparta was victorious in wrestling, and Polyneikes of Elis in running. In the forty-first Olympiad, they first introduced boxing for the boys, and Philytas from Sybaris defeated the other contestants.