How Arnold developed huge biceps?

Arnold Swarzenegger was the best bodybuilder of his time. He had 22 inch Biceps. That was a size admirable by almost anyone of his age. There were various techniques he explained that he used in order develop those huge arms. He told in a interview that he strained the muscle until it fainted. That meaning he over trained the muscle. But there is a slight controversy with over training. It is thought that over training ruins your muscle fibres but the harsh truth is that it actually builds muscle and makes it grow. He was not any ordinary bodybuilder, he took the biceps to their final peak until he was not able to do anymore.Muscle development is the final result of pushing your muscles to the limit and that is why Arnold had huge biceps.