A man must constantly exceed his level

​One of Bruce Lee’s pupils ran three miles every day with him. One day, they were about to hit the three-mile mark when Bruce said, “Let’s do two more.” His pupil was tired and said, “I’ll die if I run two more.” Bruce’s response? “Then do it.” His pupil became so angry that he finished the full five miles. Exhausted and furious, he confronted Bruce about his comment, and Bruce explained it this way: “Quit and you might as well be dead. If you always put limits on what you can do, physical or anything else, it’ll spread over into the rest of your life. It’ll spread into your work, into your morality, into your entire being. There are no limits. There are plateaus, but you must not stay there; you must go beyond them. If it kills you, it kills you. A man must constantly exceed his level.”
Source: Forbes , Author Travis Bradberry