Joshua Iyalla broke three world records — the most punches in one minute with gloves, without gloves and with dumbbells. He talks about becoming the world's fastest puncher when many said he couldn't.

The best boxers of all time—from Floyd Mayweather to Manny Pacquiao to Muhammad Ali—have different styles, but the one thing they have in common is a ripped physique. Unlike powerlifting which builds ...