Competing in the Olympic Games of the 154th Olympiad in 164 BC, the last of the "golden age" of the ancient Games,[4] Leonidas captured the crown in three separate foot races: the stadion, the diaulos, and the hoplitodromos.

Leonidas's lifetime record of twelve individual Olympic victory wreaths was unmatched in the ancient world.

[5][6][7] His record was broken in 2016 CE by swimmer Michael Phelps.

Philostratus the Athenian wrote in his Gymnastikos that Leonidas made all previous theories of runners' training and body types obsolete.

[9] The stadion and the diaulos, foot races of some 200 and 400 meters respectively, were best suited to sprinters, while the hoplitodromos (a diaulos performed with bronze armor and shield) required more muscular strength and endurance.