Bruce Lee dedicated most of his time to training.

 He wasn’t just training his muscles, but even his bones, his tendons and his skin. He wanted to turn himself into a man of steel. He did so by dedicating up to eight hours a day to physical conditioning and training. This included pounding buckets of gravel and hitting rocks and wooden planks.As the above photo shows, Lee’s training left him with severely calloused knuckles and thickened bones. The general idea was that all parts of his body should be rock hard and powerful, whether inside or outside the body. His fingers alone were so strong that he could effortlessly pierce through a coke can, back when the walls of soda cans were far thicker than they are today; Bruce Lee’s fingers and hands were quite literally weapons, honed by hours upon hours of hitting hard objects mercilessly. He spent a lot of time developing crazy grip strength, too — he was able to crush walnuts between his fingers like it was nothing. While never heavier than 160 pounds at his heaviest and standing only 5′8″, the man was ridiculously strong and was pretty much all muscle with very little excess weight.