HRmax

Once the central nervous system detects that the body has exceeded HRmax (maximum heart rate), which is about 220 beats per minute minus your age, it assumes we are in extreme danger and dumps a cascade of hormones into the bloodstream to help the body deal with the emergency situation. Most people, even martial artists, have seldom, if ever, been in a situation that would drive them into HRmax, so they do not know how to deal with its effects. The hormone dump brings out instinctive behaviors that are commonly known as the “fight, flight, or freeze” reflexes. The body prepares itself to fight, run away, or simply freeze and not move at all.

Some of the effects of a hormone dump are tachipsychia (time warp), auditory exclusion, visual exclusion (tunnel vision), tone amplification (screaming), the Moro reflex (hands-up, shoulders lifted, neck tight, face grimaced, clutching), teeth baring, snarling, fist clenching, and short-term memory exclusion. These reflexes were useful for our ancestors when they had to deal with predators. They may still be useful, but sometimes they cause problems when dealing with modern threats.

When we have trained to deal with the unexpected, such as martial arts training, we lessen the chances of reaching HRmax; our training is useful in handling such things as an unexpected attack. However, once we reach HRmax, the body thinks we are unable to handle the situation with our martial art skills and it allows our basic instincts take over. When this occurs, our martial art skills, and any other conditioned skills, are suppressed; techniques are slower, weaker, and uncoordinated.