I made a full commitment that I'm gonna be in America.

我竭尽全力留在美国。

I made a full commitment that I'm gonna go be a body-building champion.

我竭尽全力去做健美冠军。

This just means to have full commitment to something.

这只是意味着对某事有完全的承诺。

He was always a man of full commitment, so he was going to either try all in or not at all.

他一直是一个全身心投入的人，所以他要么全力以赴，要么根本不做。