Originally Posted by aliann
You may be "pushing" your punches. Normally when a student punches (depending on their rank of course) they are trying very hard to punch hard and fast. Does it seem like the harder you try to punch hard and fast the slower and more stuck your punch feels? If this is the case you are proibably tensing your muscles through out the movement. The key to fast and powerful punching in in removing the big muscles of the arm from the equation. Your arm should be loose and relaxed right up to impact (think about a towel snap). At the point of impact the body tightens for a brief moment before becoming relaxed again.
You may benefit from placing your mind on the pull back rather than the punch.
Also the more you can become still (relaxed) the better for all your movements and the overall stamina you will be able to maintain. Muscle is not the secret to speed, acceleration is and reduction of friction (your desire to muscle the movement) increases acceleration (speed and power).