triathlon; ironman race
Refers to a triathlon, especially the long-distance Ironman-branded event. The term is a compound of 鉄人 (ironman) and レース (race).
See also: トライアスロン
He participates in the Ironman race every year.
鉄人レースを完走するには厳しいトレーニングが必要だ。
Completing a triathlon requires rigorous training.