Hysterical strength refers to extraordinary displays of human strength, typically prompted by a life threatening situation. One of the most commonly cited examples is that of a parent lifting up a vehicle to save a trapped child.

This unusual reaction to a dangerous situation is believed to be caused by the body’s stress response, which triggers a rush of the hormone adrenaline. Read on to learn more about how this works, as well as for some real-life examples.

Yeah, it probably is. Enough corroborated news reports are out there to suggest that hysterical strength isn’t just a theory—there’s likely at least some truth to this phenomenon.

But it’s nearly impossible to re-create a true life-and-death situation in a laboratory setting. And even if it were possible, such an experiment would jeopardize participants’ safety and violate ethical standards for research.

So, hysterical strength isn’t something the scientific community can study conclusively.

As a result, researchers can rely only on real-life instances to explain how and why some people appear to experience superhuman strength in extreme circumstances.

Physical potential

Most of the time, we use only a fraction of our maximum theoretical strength. In fact, our bodies tend to conserve energy when possible. It simply wouldn’t make sense to use all your muscle mass to, say, pick up a pen or tie a pair of shoes.

You might use more muscle mass to lift something heavy, like a television. But even during exertion, pain and fatigue prevent most of us from accessing our full potential. This is a protective mechanism that helps us avoid injury.

The fight-or-flight response

So, how do we tap into additional strength when we need it? The key to understanding superhuman strength likely lies in the body’s response to stress, known as the fight-or-flight response.

When you come into contact with a threat, such as a wild animal or a fast-moving car, it triggers a complex physiological response. Here’s how it happens:

The amygdala

The response begins in your amygdala, the part of your brain that’s associated with fear. The amygdala activates the hypothalamus, which releases stress hormones like adrenaline and cortisol.

Adrenaline

The hormone adrenaline makes your heart and lungs work faster, which sends more oxygen to your major muscles. As a result, you get a temporary boost of strength.

It also helps by sharpening your vision and hearing. This allows you to remain alert and focused.

Cortisol

The hormone cortisol helps you access stores of glucose (sugar) in your body, which gives you extra energy for sustained effort.

Endorphins

Your body also releases endorphins as part of the fight-or-flight response.

These feel-good chemicals help reduce your perception of pain. What might usually feel painful to you will hurt less if your body is in fight-or-flight mode.

Physical conditioning

These are just a few of the physiological changes that can help explain increased strength in response to a stressor.

But research exploring athletic performance offers some additional insights. In athletes, factors like sex, age, nutrition, arousal, and mood affect adrenaline levels.

In addition, adrenaline output appears to be higher among athletes who have undergone endurance training. This may explain how elite athletes can tap into increased strength when it’s time to perform.

Limitations

Still, it’s difficult to pinpoint just how much the fight-or-flight response, including the release of adrenaline, actually boosts strength.

Increases in strength associated with adrenaline are often exaggerated. Plus, factors such as body mass limit how much any one person is physically able to lift.

In other words, it’s probably not possible for a 125-pound person with no previous weight-training experience to suddenly lift a car.

Healthline

After the stressful situation ends, the body returns to normal. Your heart rate and breathing slow, and sensations such as pain and fatigue return.

It’s at this time that you might become aware of injuries caused by overexertion, such as muscle strains and sprains.

Injuries are one of the reasons why we can’t access extreme strength easily. In the long run, repeated instances that trigger hysterical strength probably aren’t healthy.

We can tolerate occasional stressors; however, when stress becomes constant, it can wear the body down. Chronic stress can lead to mental illnesses, headaches, heart problems, increased susceptibility to infections, and issues with digestion, among other health conditions.

Here are a few examples of people who displayed extraordinary strength and endurance in the face of danger.

Young woman kills “Dirty John”

This true-crime story was the subject of an LA Times investigation and later a podcast, a documentary, and a television series.

It centered around 57-year-old con man John Meehan, who posed as a doctor in 2014 to woo 59-year-old Debra Newell. The story culminated in Meehan attacking Newell’s 25-year-old daughter Terra with a knife after Newell left him in 2016.

Although she’d been taken by surprise, Terra was able to somehow gain control of the knife. She fought off Meehan, stabbing him 13 times. He died several days later in the hospital.

It must have taken considerable strength and endurance for Terra — who was 5 feet, 2 inches tall — to overpower Meehan, who was 6 feet, 2 inches tall and at least 30 pounds heavier than her.

Mother fights a polar bear

In 2006, The Globe and Mail reported that a 41-year-old mother living in a remote village in northern Quebec had wrestled with a polar bear to protect her two sons.

Lydia Angyiou was walking with her sons when nearby children alerted them to an approaching polar bear. She told her sons to run, placing herself between them and the bear. Then she attacked the animal, kicking and punching it.

When the 700-pound bear swatted her, Angyiou fell on her back but continued to kick her legs. Fortunately, a bystander had seen what was happening and shot his rifle into the air several times to startle the bear before killing it.

Angyiou, who came away from the incident with only a few cuts and bruises, received a national award for bravery.

Teen lifts a car to save neighbor

This classic story of hysterical strength appeared on CNN and in The Washington Post in 2019.

Sixteen-year-old Zac Clark was outside with his mother when they heard a neighbor crying out for help. The pair rushed to the house, where they found the neighbor’s 39-year-old husband pinned underneath his car.

Zac, a high school football player who had previously deadlifted just over 400 pounds, moved quickly to the front of the car, lifting it just long enough for the two women to roll the man out from underneath. The man came away with non-life-threatening injuries, while Zac experienced a sore back and legs.

In a life-or-death situation, it may be possible to experience a strength boost.

This phenomenon, while not recognized by the scientific community, is known as hysterical strength, and is activated by the body’s fight-or-flight response.