LIFE magazine ran one of the late Flip Schulke's photographs of Muhammad Ali in 1961 "training" underwater in a Miami swimming pool. Ali swore that the underwater workouts made him the fastest heavyweight in the world.
This is the punch that sent George Foreman sprawling to the canvas in the round. The "Rumble in the Jungle" was the fight that Muhammad Ali deployed his famous Rope-A-Dope strategy (allowing big George to punch himself out). the rest is history.