Sunday, 9 December 2012

Physiological Stress vs Physical Stress

Physiological Stress versus Physical Stress in Tactical Training

There are many videos of courses of fire and range drills post on the internet that combine physical activity and shooting. Many of the ‘experts’ post these segments claiming that it will “simulate a body alarm response” or ‘how your body will react in combat”. Unfortunately, the science does support those statements. There is a difference between Physiological Stress and Physical Stress.
Physiological Stress is a natural defence mechanism that allows us to deal with a threat or perceived threat; either by hurtling towards or running in the other direction.  When your body executes the “fight-or-flight" reaction or Body Alarm Response (BAR), the Sympathetic Nervous System (SNS) initiates, synchronizes and orders specialized changes in how the body performs.  Hormones, including adrenaline, facilitate immediate physical reactions preparing for violent muscular action. These include the following: speeding up of cardiac and respiratory system, constriction of blood vessels in some areas of the body, dilation of blood vessels in other areas, smooth muscle is relaxed to allow more oxygen into the lungs, discharge of stored nutrients (chiefly fat and glucose) for muscular energy, slowing or stopping of the digestive tract, and dilation of the pupils. This ramps the body increasing strength and speed, slows needless body processes and increases the attributes of others needed to fight. The affect on senses is the most interesting. Humanity has evolved as a vision based predator. The dilation of the pupils allows us to collect in more visual data, even in lower light, increasing our ability to judge distance but only on one target at a time. Tunnel vision or peripheral narrowing is very common. Also, the body reduces sensitivity of other senses: auditory exclusion and reducing pain sensitivity.  This allows us to target and deal with a threat. It can have negative effects in a team  and  multiple target environment. The length of Sympathetic Nervous System (SNS) activation lasts until the perceived threat or actual threat has been dealt with. Then the Para-Sympathetic Nervous System kicks in and slows the system down.

This is Physiological Stress

Physical stress caused by exertion is the expenditure of energy by skeletal muscles; a strenuous or costly muscular effort. The effect of exertion physical stress differs at the level of activity and the body’s physical conditioning.  Increased physical activity requires a matching increase in metabolism, cardiac output, respiration rate and produces more waste products that must be disposed. The increased activity produces heat.  Dissipated through perspiration and increased respiration which results in fluid loss (blood volume decreases) and electrolyte consumption. The intensity of exertion physical stress can be measured by the rate of which oxygen is expended, heat is produced, respiration rate and heart pace.  Strenuous or endurance training can deplete the body’s energy and fluid levels enough to have effects on cognitive function. On the cessation of high physical activity, heart rate decreases rapidly, respiration rate returns to normal and body heat is dispelled faster.

This is Physical Stress. RCN Boarding team member
Courtesy of CF Combat Camera
Click on to Enlarge
The differences are quite evident. Physical stress is dependent on the level of activity, physical conditioning and recovery time. It has little to no effect on cognitive function or sensory system except at extreme levels or duration. Most of those are due to hypoglycemic, dehydration and fatigue. Physiological stress of a Body Alarm Response (BAR) is uncontrollable,has different metabolic effects,  increases strength and agility, has targeted effects on sensory system and does not dissipate until threat is gone or controlled.

Activating the BAR

SureFire Free Shot Timer App
for Iphone
The body alarm response is activated generally when reaction time is short, when surprised or startled, when reactionary gap is small and when unprepared. Which of these can we control in a training environment? Reaction time and Reactionary gap. The use of shot timers and competition between shooters is an excellent technique to get a little stress in a course of fire. An enforced high standard of testing to push performance creates stress; nobody wants to fail. Set up the graded final course of fire in an unseen area and segregate shooters before and after.  There are many ways to accomplish this goal. A knowledgeable, experienced instructor will have a few in his toolbox. None of these techniques can activate a Body Alarm Response similar to combat. Which one of these do have control over in an actual threat response? Preparation! The best way to reduce the effect of the BAR is realistic relevant training, strong situational awareness and an aggressive attitude.

Does Physical Stress have a place in tactical training?

Absolutely. It plays a valuable role in physical conditioning and mental toughness. It prepares you to control your breathing. It develops dynamic explosive movements for the an equally dynamic environment  Training in full kit with strenuous physical activity will simulate the physical stresses of combat. Putting aside physical discomfort and distractions focusing on the current task is a principal attribute in a tactical operator. There is an old saying in military physical conditioning, “running will make you fit, rucksack marches will make fit and hard.” But, it does not simulate the physiological effects of a Body Alarm Response.

I wonder if the people in the video below understand the differences between Physiological Stress and Physical Stress. If truly in a life or death fight, the BAR would activated and the stress effects on performance would be quite different.

There is a crucial difference between Physiological Stress and Physical Stress.  Both are of great consequence in a tactical training regimen. However, one is not the other.
Take care out there.

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