Veteran police officer, police trainer, and combat physiology researcher Bruce Siddle delivered a powerful keynote address at TREXPO East Wednesday.

Siddle, author of "Sharpening the Warrior's Edge, argued that many warriors fail in their mission and suffer calamity because they do not understand how combat stress and fear affect their performance. He also said that police trainers who do not have a grasp of the human element of combat and the physiological stress that it places on the body often set up their officers for failure.

One of the least understood aspects of combat, according to Siddle, is the nutrition required for optimal performance. He said it's important for officers to understand that what they put into their bodies before going on duty and during their shifts can determine the outcome of a fight.

Siddle explained the need for both protein and carbohydrates in an officer's diet. He also discussed the role of both slow-burning carbs (fruits and grains) and fast-burning carbs (chocolate and other sweets) in officer performance. He said that officers who were part of a raid team or other unit anticipating immediate combat would be well advised to consume energy bars or even Snickers candy bars to give themselves a 10- to 20-minute spike of energy.

Dehydration can also affect officer performance under fire. "Even at one-percent dehydration, you lose much of your fine and complex motor skills," Siddle said, urging officers to drink water throughout the day.

Maintaining proper nutrition and hydration can help reduce the influence of fear on the body, Siddle says. "Fatigue leads to fear, and fear leads to the triggering of the sympathetic nervous system (SNS)," he explained. 

The SNS-often called the "fight or flight" circuit-causes the heart to race, blood pressure to rise, and other physiological reactions intended to make a person fast, quick, and strong. However, these reactions are not always beneficial to a warrior and the body cannot maintain this state for very long.

Siddle explained the SNS response as the way you would feel if you were "walking through the woods, turned a corner, and came face to face with a grizzly bear. The SNS is the startle reflex that you experience in a life and death situation," he explained.

The SNS has a variety of effects on a police officer in combat. For example, an officer experiencing an SNS response cannot focus on the front sights of his or her pistol. This is why Siddle recommends that officers train to respond with aimed fire and with combat point shooting. "If you have time and distance, then there is no SNS response and no startle," Siddle said, explaining that both aimed fire and point shooting have their place.

Siddle also explained that the SNS loop is the reason that some warriors become hypervigilant to the point of not being able to function in combat. He used two examples to explain what he meant. In one, a police officer under fire performed three tactical reloads of his magazines without firing a shot. In the other, Civil War soldiers loaded multiple rounds down the barrels of their muzzle-loaders and the rifles were found on the ground after the battle unfired. One rifle recovered at Gettysburg was still loaded with more than 20 rounds.

As Siddle explained, however, the SNS response is only one part of being startled in combat. The body at rest experiences a balance of influences from the SNS and the PNS, the parasympathetic nervous system. This balance is called homeostasis. Once the individual is no longer in abject fear of death or major injury, or is wounded, or just aerobically exhausted, the SNS reaction leads to what's called a PNS backlash. A warrior experiencing this reaction may feel dizzy as his or her blood pressure drops rapidly and he or she will have a hard time functioning. This reaction is also one of the factors in critical incident malfunction.

Siddle recommends that if an officer experiences a PNS backlash that he or she should lay horizontal, eat some candy or other fast-acting carbs, and follow it up with some protein. Officers in this state should not be questioned or asked to write reports until they have had some proper nutrition, Siddle says. "Without the proper fuel, they will only know part of the facts not all of the facts," he explained, adding that critical incident amnesia caused by the release of cortisol in the brain may prevent the officer from ever remembering all of the details of what happened.

According to Siddle, the best way to reduce the chance of being startled in combat and experiencing an SNS response is to have the mindset of a predator, meaning a natural predator like a tiger. "The tiger is mission-driven, it exhibits quiet confidence, it is highly aware of its situation at all times, and it acts with controlled aggression." He went on to explain that these attributes can make a warrior less likely to be startled by sudden combat. For example, being situationally aware increases the time and distance between you and the threat, making it easier for you to effectively respond and minimizing fear.

Closing his presentation, Siddle said it was critical for police trainers to take a more holistic approach to combat training. "We need to look at all of the intangibles of human response and bring them together in our training." He also argued for combining fitness, use-of-force training, close-quarter combat training, and defensive tactics training into one discipline that is based on research into the physiological reaction of warriors to combat. "We need to avoid the flavor of the month," he added. "The flavor of the month kills and advanced techniques are really just the basics mastered."

He also had a final message for the TREXPO East audience: "I encourage you to take your profession seriously and to study combat human factors. Little things make a big difference in combat," he said as he left the stage to enthusiastic applause.