When encountering a threat, humans typically have one of two instinctual reactions, with an occasional third; we fight, we flee, or, if we are unlucky, we freeze.

For many, especially untrained individuals or for those overwhelmed by a threat, this can be a subconscious, automatic decision. For trained individuals this response can be honed and controlled at a more conscious level. Whether the decision is a conscious one or not, your brain will do a quick calculation based on your past experience, your skill level, and your conditioning, to determine which option is best for the situation at hand. The most important part is often not which decision is made, but the speed at which the final decision is reached (supported by whether or not you can commit to it).
“Strike fast, but run faster” – Unknown
The following is an excerpt from a previous article found here.
“The fight or flight response refers to physiological reaction that occurs when a person is placed in a threatening situation. ‘Fight or flight’ simply describes the two basic options that are instantaneously weighed in order to resolve the dangerous situation being presented, by either making a quick escape or fighting back.
The physiological process of this response begins with one or several of the five senses, typically vision. A person will see threatening stimili, such as person or animal, the stimili is then sent as a signal, via the optic nerve, to the brain. This threat signal is usually processed in the amygdala, known as the ‘fear centre,’ which sends signals to the hypothalamus, which in turn activates the nervous system. Another signal then stimulates the sympathetic nervous system, which will send impulses down the spinal column to the adrenal gland, where the hormone epinephrine is released (also known as adrenaline). Epinephrine will cause the heart rate to increase, allowing it to be sent further throughout the body as the heart beats faster. At the same time, this stress hormone will signal the liver to release glucose, which will then be converted into adenosine triphosphate (ATP), which is an energy carrying molecule used to activate muscles. The heightened level of epinephrine in the body will also activate the lungs, causing the breathing rate to increase in order for the body take in and utilize more oxygen through dilated blood vessels. The pupils in the eyes will also dilate, to take in more light and increase visual acuity. Finally, the dilation occurs in the blood vessels of the ears, for increased auditory perception.
While the body is activating these defensive measures, it is simultaneously subduing processes deemed unnecessary during a dangerous situation, such as digestion, in order to free up energy for fighting or effecting a hasty retreat. The elevated levels of epinephrine and increased activation of these bodily processes will increase body heat, which ‘warms up’ your muscles in seconds as the mind registers the threat.

Psychologically, the combination of the increased heart rate, sweating, and the explosion of energy in the muscles, create a sense of acute awareness of the current situation and the ability to act quickly. While this illustrates a case in which the entire process runs smoothly, you must also be aware of the case in which it fails, known as ‘condition black.’ Condition black is also referred to as ‘non-functional freezing,’ locking up during a dangerous situation, preventing the individual from fleeing or fighting. Cognitively, a sense of increased aggression will be associated with the ‘fight’ response, and a combination of fear and anxiety for ‘flight.’ While a sense of fear and anxiety is commonly associated with ‘freezing’ as well, it often includes a physical sensation of stiffness. During this ‘freeze’ response, the parasympathetic nervous system dumps large amounts of hormones into the body, the same hormones that return the body to its relaxed state after a fight. This sudden increase of ‘recovery hormones’ during a dangerous situation will have the opposite effect of the desired ‘fight or flight’ response; mixing panic with an inability to act quickly. Although freezing can be useful in situations in which a person must remain still in order to hide from an attacker, it can be detrimental when faced with an attacker head on.”
In Krav Maga, we accept these natural reactions and work with them. We have a decision to make: If we are following the proper stages of self-defence, then we will choose Flight, as (A) Avoidance is the first choice when we have it and it is appropriate (for civilians it usually is, for those whose jobs require them to stay it will not be). Or, if we cannot avoid the fight and we cannot (D) Diffuse the situation, we fight. Depending on the scenario and how quickly you realized the fight is unavoidable, you will either act Preemptively (PE) and strike first, or React (RE) defensively to their incoming attack.
The “Freeze” reaction is a double edged sword; in some situations the correct tactical response to stop moving, in others it renders you defenceless.
Example 1: You are walking in the plains of Africa. You spot something. That something, you think, is a pair of eyes peering at you from the tall grass. You FREEZE! This is both to ensure that you identify the threat correctly, before making a decision, and to not activate the predator’s response to running.

The ability to recognize eyes and a face is so ingrained in our biology that our brains have sections dedicated to this task. This is a very primal, predator response; “I see face, I decide fight, flight or freeze.” Remember, these responses threaded throughout our biology as part of our survival instinct. So rather than struggling with them, train them.
Example 2: You are a Special Operations group moving silently through the night. You are still 1km from your designated target. A group of teens is up late, past the local curfew. You freeze, remaining motionless and silent, so as not to be spotted. The threat of detection passes and you continue.
In both examples, the freeze response offers a tactical advantage, as the threat is present but not active. But what if the eyes in the grass suddenly charged, or the teens turned out to be hostile? In the worst case scenario, the freeze response can become “code black” and turn into a catastrophic mental failure, preventing you from acting at all; the dreaded Non-Functional Freeze (NFF). This is the kind of freeze we hope to avoid. Some individuals are fortunate enough not to have a code black or NFF trigger, others will only know when it happens. If your brain is prone to “code black”, hopefully you have make correct life decisions and manage to avoid dangerous or life-threatening situations. If not, you may be in for a world of hurt.
One of the most effective ways to avoid a code black situation, especially under the threat of violence, is to train. Training is a form of exposure therapy, especially with the intensity of Krav Maga. Krav Maga cannot be called Krav Maga if the training never forces you to push your physical and mental limits through stress testing. This regular and relatively safe training exposes you to higher levels of mental and physical stress in slowly increasing doses, which allows your body to adapt and get used to the stimuli (internal and external). The more you are exposed to this stimuli, the easier you can turn a freeze response from an NFF to a tactical freeze to action, thus making the correct decisions in the moment and avoiding being overwhelmed by a real-world threat.
Under threat of life and death, do you know which response you are most likely to have? The right one could save your life, but the wrong one…
*Topics under any principle category (Eg. Krav Maga Principles) may be updated from time to time. So check-in every few months to see if the posts have been updated.