Heart Rate & Motor Skills

The effect of increased heart rate on motor skills function is a common topic of discussion among tactical athletes and self-defense specialists. The existence of the Survival Stress Response, or SSR, and its influence on the sympathetic nervous system have been discussed since at least the 1970s. Military and law enforcement trainers have worked with leading physiologists to determine what these effects are and how to overcome them.

Survival Stress Response

SSR is a scientific term to describe what is commonly referred to as the fight-or-flight syndrome. It occurs when a person is suddenly thrust into a life-threatening situation with no forewarning. Among the physical symptoms that arise from the SSR are auditory exclusion -- most easily described as either temporary deafness or selective hearing, depending on severity -- and visual exclusion, which may be either tunnel vision focused on the threat or even a blackout if the situation is scary enough. The third symptom of SSR is increased heart rate.

Heart Rate Factors

The elevated heart rates induced by SSR can cause serious repercussions to motor skills function. At 100 to 110 beats per minute HR, fine motor skills may degrade noticeably. These are movements that involve independent movements of the individual fingers and hands, such as playing the piano, or specifically, performing precise movements such as hooking a rappelling rope into a climbing harness prior to a SWAT team assault. At 115 to 145 bpm HR, complex motor skills begin to disintegrate. These are more robust movements for performing joint lock restraint holds in a close-combat situation such as prisoner restraining.

Gross Motor Skills

Theoretically, the only motor skills to survive the SSR are gross motor skills. Basic striking techniques such as punches and kicks, simple shooting techniques such as unaimed pint-shooting and other simple movement skills are gross motor skills. These movements are possible even when the heart rate exceeds 200 bpm. This is far in excess of the exercise-induced heart rate of most conditioned athletes.

Fallacies in the SSR Concept

There are several fallacies in the SSR concept regarding heart rate and motor skills degradation. The first of these is several millennia of evidence to the contrary. Although the degradation of motor skills may occur in untrained people under stress, there is ample historical and modern evidence that it is completely possible for a well-trained person to perform complex, fine-motor skills under the most stress-inducing situations. Additionally, trainers have discovered ways to test a tactical athlete's ability to function under the physiological effects of SSR in a training environment. These tests have shown that the apparent effect of heart rate on motor skills function may be more psychological than physiological.

Overcoming the SSR

Realistic, focused training can overcome the loss of motor skills due to high heart rate under the effect of SSR. According to shooting instructor and self-protection expert Dave Kenik, in his book "Armed Response," in studies conducted at the Lethal Force Institute in New Hampshire, trained shooters were injected with epinephrine to induce an SSR-like adrenaline spike, including the resultant heart rate increase. These shooters managed to perform at nearly the same level as without the injections. Additionally, modern trainers have discovered that it's possible to inoculate trainees against the stress of SSR by familiarizing them with the sensations they will encounter in real-world conflicts through realistic training with Simunition wax bullets fired from real firearms and scenario-based role-playing during training evolutions.