he'd kick

Ciao a tutti

Due persone stanno correndo. "We ran to the top of a wooded hill two and a half miles from the gym and started back, still stride for stride: it would be that last two hundred yards when he'd kick". Come posso tradurre quel "kick"?
Il resto della frase mi suona così: "Corremmo fino in cima alla collina coperta di boschi, distante due miglia e mezzo dalla palestra e poi cominciammo a tornare indietro, ancora a lunghe falcate. Erano gli ultimi duecendo metri scarsi quando HE'D KICK".
Come posso tradurlo?

I don't know how to translate it into Italian, but it means that he made his greatest effort during the last two hundred yards of the run.

"Quando ha tirato fuori il massimo" oppure "quando ha dato il meglio di sè".

Sprint finale?

If you watch athletics, you often find that middle-distance and long-distance runners have a steady pace for the majority of the race, then speed up significantly for the last 200m or so. That is what is meant. So a translation of "speed up" would be appropriate, or find out the exact phrase that is used by athletics commentators.

Andrebbe bene anche "quando ha alzato il ritmo".