Speed punching

While punching on a bag, act as if it were an opponent, and your target: side-step as it swings back, and attack it firmly. If you are rank beginner on the punching back, reach higher on the bag -- the bag is softest on top, middling at the middle and hardest below. The last stage -- hardest -- you must try after your punch becomes more perfect. Remember never to slacken your fist while punching -- otherwise wrists bear the brunt.

Best boxing!!