Courage of the Heart
I must admit that I have never been a boxing fan. However, Muhammad Ali demonstrated the kind of "courage of the heart" defined by the original Latin and Old French meanings of courage in his passion and commitments. He lived his life with heart based on his innermost feelings, inner strength, and temper. He also had the characteristics of bravery, wrath, pride, confidence, and lustiness that are more characteristic of English-language definitions of courage.
He also had the required discipline to accomplish his own goals. Consider these quotations cited on Wikipedia
Float like a butterfly, sting like a bee.
I hated every minute of training, but I said, 'Don't quit. Suffer now and live the rest of your life as a champion.'
Don't count the days, make the days count."
Float like a butterfly, sting like a bee"
was well-known. However, I don't remember ever hearing either of the other two quotations. Both of these are powerful statements about courageousness, discipline, and the willingness to take risks.