Breath Control. To generate maximum power in a Taekwondo technique, you must use proper breath control. See the breath control topic for more information on proper breathing. The kiai (yell) is used during the execution of any Taekwondo technique to control the breath and focus total concentration and power. See the kiai topic for more information on the kiai. Dercks, Lässig, and Ebert, at the Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany conducted a study on the acceleration and timing of a Karate punch inside the breathing cycle. Subjects performed a punch during four phases of breathing: during inspiration, after inspiration, during expiration, and after expiration. The peak value of breath flow was found after the maximum velocity of the punch. The highest amount of acceleration of a punch appeared during expiration of a breath. The well performed Karate punch seems to be in fixed relation to breathing. Antagonist muscles were activated before agonist muscles. Acceleration did not correlate with trainees ranks.
Calm Mind. To execute a powerful technique that strikes its intended target before the opponent can react, the mind must remain calm and relaxed, while also achieving maximum concentration. Concentration does not mean you must be tense. On the contrary, to concentrate on the movements of an adversary, the mind must be calm so it may react quickly to any attack. Calmness in the mist of turmoil can be achieved through the practice of meditation or through hours and hours of free-sparring. With a clam mind, you is not distracted by internal negative thoughts, the opponent, or by other external distractions.
Leverage. The angle of a limb joint at impact affects the power delivered by the limb. When a limb is at full extension (180º), it has no power left in it. If the limb has some bend in it (<180º) at the moment of impact it still has some power left in it that may be used if the target range was misjudged and more extension is required.