Muhammad Ali began boxing in order to learn how to defend himself and stand up to others. He was just twelve years old when he began fighting.
According to About.com, when Ali was twelve years old, his bicycle was stolen from the Columbia Auditorium. Ali was so furious about the incident that he immediately reported it to a police officer named Joe Martin who was in the basement of the Columbia Auditorium at the time. In addition to being a police officer, Joe Martin was also a boxing coach at the Columbia Gym. When Ali said he wanted to fight whoever stole his bicycle, Joe told him that he needed to learn how to fight first. That simple statement launched one of the greatest boxing careers in history.
Young Ali took his training seriously. He was in the gym six days a week, and he would get up early each morning to run. In the evenings, Ali would be at the gym for several hours working on his technique and endurance. When Martin's gym closed in the evening, Ali would go to another gym to train. His long hours in the gym paid off, and his boxing skills became extremely refined. Ali went on to make history by becoming the first boxer to win three heavyweight titles.