With each repetition, I felt more confident. (Para.8)
Meaning: As I repeated my actions, I became more and more sure of my success in the Olympics.
confident: a. having belief in one's power or ability
I'm confident that our team will win the match. 我相信我们队会赢得这次比赛的胜利。
He feels confident about passing the exam. 他相信自己会通过考试的。