An Exploration of Force and Attention

Abstract

Many people exhale loudly when performing an action that requires force. ‘Grunting’ has been found to increase force when weightlifting and playing tennis, as well as possibly even being capable of distracting your opponent. The kiai (key-eye) is a breathing technique taught in martial arts that involves the sudden exhalation of breath when conducting a move that requires force (e.g., a kick), and can be considered analogous to a grunt. In martial arts, it has been speculated that this can lead to increased striking force in addition to possibly being able to distract an opponent rendering him or her less capable of defending the attack. However, no empirical testing has been done to corroborate these claims. The present experiment explored whether the kiai does lead to an increase in force, and whether it is also capable of distracting the opponents ability to determine where an attack will be targeted. Kicking force was measured with participants from a martial arts school who performed kicks while incorporating, or not, the kiai. Force was significantly higher with the kiai than without. In order to address distraction, a separate group of participants viewed video clips of person kicking either high or low. Each clip was presented either with or without a sound. The participant pressed one of two keys as quickly as possible to indicate whether they felt the attack was going to land above or below midline. Participants were significantly slower and less accurate in their responses when there was a sound present.