In 1962, Muhammad Ali was still Cassius Clay and already understood something most fighters did not, attention mattered. Around that time, Clay told reporters he trained underwater to build lung strength and speed. Many who were close to him later said this was not something he genuinely did as part of his routine. It was likely invented, or at least exaggerated, to sound different, futuristic, and unbeatable. It worked. The claim caught the attention of Sports Illustrated, who wanted to see it.

Muhammad Ali's inspiring speech about life and death - Andscape

Muhammad Ali: 'Just take me to jail,' conscientious objector speech - 1967 — Speakola