THE AUTONOMIC NERVOUS SYSTEM: HOW TO CONTROL THE FIGHT OR FLIGHT RESPONSE IN FIRST RESPONDERS

Your heart rate quickens, the blood pounds in your ears, your palms get sweaty, your mouth gets dry and without even noticing, your peripheral vision narrows and the noise around you dies out.

These are the life-saving effects of the sympathetic branch of the autonomic nervous system in action, and first responders are likely to feel some of these symptoms multiple times a shift. But while this ‘fight or flight’ response is crucial for human survival in high stress scenarios, a failure to recognise and control this response on the frontline has the potential to end in catastrophe. 

The Sympathetic Nervous System: The Governor of Your Survival Instinct

The autonomic nervous system has two primary branches; the sympathetic and parasympathetic nervous systems. When faced with a threatening or dangerous situation, the sympathetic branch activates, and your body experiences some involuntary responses that are geared towards survival.

Alongside those listed above, other symptoms include elevated blood pressure, quicker breathing, excessive sweating, muscle tension and anxiety. The ability to perform fine motor skills decreases, you may feel sick or nauseated as blood is diverted away from metabolic processes such as digestion, and the glucose released by the liver combined with elevated levels of adrenaline prepare you for action.

This is commonly known as the ‘fight or flight’ response. 

Fight or Flight Response: How Stress Impacts First Responders

Both of these responses are designed to minimise your exposure to the stressor (the cause of the threat or danger) by either eliminating it or running away from it, neither of which may be particularly appropriate in a first responder context.

• Fight:

If you believe you have the potential to physically overcome the threat, your sympathetic response is to fight. You’re likely to experience heightened anger and aggressiveness and your ability to problem solve, rationalise, deescalate, and think clearly can become compromised.

This is particularly problematic for police officers who can potentially make mistakes with their use of force and enter a conflict too high on the continuum. Not only can this escalate what should have been a manageable situation, but it could also lead to legal or professional consequences, and perhaps even prove fatal.    

• Flight

The flight response occurs when you believe physical confrontation is not an option and the only way you will escape safely is to flee from the stressor.

This is a perfectly acceptable response for a member of the public faced with danger. As a first responder, not so much.

A large amount of the training that you undertake as a first responder surrounds recognising danger and getting close enough to be in a position to keep the public safe, often by placing yourself between them and the threat.

By succumbing to a flee response, you are failing to fulfil your operational duty to protect the public.  

The Parasympathetic Nervous System: Recovery and Stress Regulation

The other branch of the autonomic nervous system is the parasympathetic nervous system. This is the system responsible for balancing your heightened sympathetic response.

Once the threat has passed, the parasympathetic nervous system kicks in to bring your body back to its baseline so you can continue your day. It drops your heart rate and slows your breathing, it tells your body to resume salivating and digestion, drops your blood pressure and releases your muscle tension.

Unfortunately, in situations of severe stress, the autonomic nervous system shifts towards a parasympathetic influence if the threat is believed to be too powerful to overcome or escape, causing a mixed autonomic state. This can manifest as either a freeze or fawn response. In extreme situations, this can even lead to a total override causing a system shutdown (fainting).

Freeze or Fawn: When Stress Becomes Overwhelming

• Freeze

This is the 'deer in headlights' response where no matter how hard you try, you are unable to move, seemingly frozen to the spot. It is a result of the complex interactions between the sympathetic response and the parasympathetic influence and in this state – despite the presence of a threat or danger – the body can actually present with symptoms of a parasympathetic response which can lead to abnormal decision making.

For first responders, this response presents an extreme danger - standing in a burning building unable to move, failing to find cover when faced with a firearm, or submitting to verbal and physical abuse with no defensive action.

• Fawn 

This response is less established in classical physiology and more common in trauma literature, but it is a result of complex interactions between multiple systems where the body’s reaction is to comply in order to avoid conflict.

This is another response that could be potentially catastrophic for police officers, as it submits the officer to the demands of the offender and leads to a significant power shift.

How to Master Your Stress Response

It is important to understand that experiencing either a fight, flight, freeze or fawn response in the face of a stressor is not a sign of weakness. Rather, it is a survival mechanism designed to keep you alive.

As a first responder, it is crucial that you have the ability to recognise and control this stress response to ensure you can still perform your role safely. Key strategies include maintaining a high level of fitness, alongside skills such as breathing techniques, controlled stress exposure, and inoculation. 

Breathwork: Regroup and Refocus with Controlled, Deep Breaths

When breathwork first burst onto the scene, it was aligned with practices such as yoga and meditation which for a long time were not linked with human performance or physical capacity. As the benefits have become better understood, however, it has become clear that this is one of the most efficient and effective methods of stress management and stress tolerance available.

Box breathing (known in first responder and military settings as ‘tactical breathing’) is one of the most popular methods, and involves inhaling, exhaling and holding your breath for four-to-six second counts.

Box breathing is useful in moderating the sympathetic response by stimulating the vagus nerve, which helps to activate the parasympathetic response and lower heart rate, slow breathing and moderate blood pressure. This is best deployed in the lead up to a sympathetic response or as soon as the symptoms of a sympathetic response start to occur.

Low Risk, High Reward: Stress Training in Controlled Environments

Stress exposure and inoculation are common activities in academy settings or other training environments, largely through simulations, practice scenarios and drills. Typically, this involves creating a mock high-stress environment with a task or multiple tasks that mimic occupational requirements.

In these settings, the consequences of failure are far lower than in a real-world environment which makes this a useful tool for repeated exposure to situations that have the potential to elicit extreme stress responses. Repeated exposure to these tasks in a controlled environment increases the likelihood of a more measured response to a real-world event.

This method of stress management training requires a lot of resources, so it can be hard to undertake by yourself. Something that you do have complete control over is maintaining a high level of physical fitness and regularly experiencing a high heart rate in your training. 

How Physical Fitness Improves Stress Tolerance and Performance

Not only does regular exercise improve your ability to tolerate stress, but higher base-line fitness levels improve your ability to cope with the sympathetic response without succumbing to an extreme ‘overload’ response such as freeze, fawn or fainting.

A lower baseline heart rate can help to moderate your heart rate during a stress response. Additionally, the volume of stress hormones released is smaller than unfit individuals and the conditioning of the cardiovascular system mitigate the factors that may increase blood pressure. Overall, this leads to an increased likelihood that you will be able to retain your focus, fine motor skills and decision-making ability when exposed to an extreme stressor.

Long-term, this also leads to better health outcomes, as the post-exposure stress response is shorter, and the return to baseline occurs quicker following the parasympathetic response.

This requires a balanced approach to training. Steady state cardio building baseline cardiovascular fitness, high intensity cardio building top-end fitness, and strength training are all equally important.

This doesn’t necessarily require a specific style of training or a particular training program, and assuming your current program is well-rounded, you’re most likely improving your sympathetic stress response already, but there are some important factors to consider as a first responder doing high volume or high intensity training.

Sympathetic Overreaching: Managing Nervous System Fatigue

High intensity cardio and/or resistance training with high nervous system load (explosive or very heavy movements) cause a sympathetic response. First responders who are exposed to a lot of sympathetic stress responses at work, who then regularly train with high intensity or high load, can be prone to sympathetic overreaching if their volume and intensity is not balanced.

To ensure this doesn’t occur, high stress or high fatigue workdays shouldn’t be paired with high stress training sessions (for more details on structuring training around your work, check out our article on Flexible Periodisation).

Additionally, you need to be aware of the signs of overtraining. A higher-than-usual resting heart rate or resting blood pressure, irritability, decreased performance, taking longer to recover and poor sleep are all signs that the body’s sympathetic nervous system is overactive.

If you do start to identify these symptoms, take a deload week (cut intensity by 20-50%) or a total rest week and if symptoms don’t subside, seek medical advice.

Sample Training Plan for First Responders

The following training cycle is adapted from our  Flexible Periodisation article and is based around a firefighter’s 10/14 roster. This would be suitable for improving the sympathetic stress response while avoiding overtraining, as it factors rest days on high fatigue work shifts and incorporates both high-intensity and steady state cardio with resistance training.

This doesn’t consider the specific jobs attended in each shift that may have caused a sympathetic response, so you would need to be flexible with each individual training day, but it accounts for the sympathetic pressure of fatigue and shiftwork, while incorporating a balance of steady state cardio, high intensity cardio and strength training.

Key Takeaways

Understanding the cause and effect of the autonomic nervous system is crucial for the longevity and overall health of first responders. If you want your wellbeing to extend beyond your career, it’s important to develop control over your stress response to ensure effective decision making, appropriate use of force, and safety for both yourself, and the public.

While crucial for human survival, the sympathetic stress response can affect your ability as a first responder to safely and effectively uphold your responsibilities to the public.

Ultimately, the goal is not to eliminate the stress response, but to harness it with breathwork, controlled stress exposures and maintaining a healthy lifestyle by doing regular high-intensity cardio, steady state cardio and resistance training.

By understanding how your body reacts and building the capacity to regulate your stress response, you place yourself in the best possible position to perform when it matters most.