Some characters are strong. In many works, this can easily be justified - either superpowers are known to exist, or Charles Atlas Superpower is a fact of life. But in some settings, the author needs a more down-to-earth explanation for why one guy can throw cars around like they're made of tissue paper. When someone is called upon for said explanation, the following lecture will usually occur:
"You ever hear about moms lifting cars off their kids? The human body is actually capable of incredible strength, but the brain inhibits it most of the time in order to keep our muscles from tearing themselves apart under the strain. His body is doing the same thing, but he's in that state of strength all the time."
Essentially, this is Explosive Overclocking applied to human beings who lack the Required Secondary Powers to handle it. This can be used as a Hand Wave or Played for Drama; in the latter case, expect the danger of a Heroic R.R.O.D. resulting from overuse of this strength to be heavily played up.
The principle behind this is Truth in Television, but the idea of these inhibitors being permanently turned off or granting anything that could be considered true Super Strength is most emphatically not. And if you could do that, it wouldn't take long to do serious damage to your body. Compare 90% of Your Brain, where powers activate the unused brain potential instead of unused muscle potential.
Compare Die or Fly.
- Shizuo Heiwajima from Durarara!! seems to have been born without the ability to control his own strength. As a kid, his bones would routinely break under the strain. However, he recovers stronger every time, so as an adult, he doesn't usually get that particular side effect.
- Ayumu, the titular zombie from Is This a Zombie?, can remove his inhibitors on his muscles in combat. The downside is that he's prone to damaging his own body from the strain and impacts.
- Kenshiro from Fist of the North Star gives a simple but amazing explanation as to how strong he is in comparison with other people.
Kenshiro: Most people only use 30% of their natural strength. That's not much. The secret to Hokuto Shinken is controlling the other 70% as well.
- In A Certain Magical Index, one of the many powers that Acqua of the Back gets from his ability Divine Mother's Mercy is to use 100% of his body's potential. Since he also has superhuman durability and endurance, he doesn't have to worry about burning out and damaging his body unless he faces something truly challenging like an angel-class being.
- In Berserk this is one of the effects of the Unstoppable Rage induced by the Berserker Armor. The armor extends spikes into the user's body to prevent it from tearing itself apart with its increased strength, with the trade-off that the user is likely to bleed to death once they calm down.
- In Naruto, the first gate of the Eight Gates, the Gate of Opening, removes the brain's limits on the muscles allowing the muscles to use 100% of their strength.
- Lampshaded with Deku's One For All "1 Million Percent" Delaware Detroit Smash in My Hero Academia, which is explained later by a doctor as Deku using hysterical strength in a moment of desperation, combined with the full power of One For All, which already wrecks his body when he goes full bore with it, in a colossal Megaton Punch that takes out a foe who Deku believed could even tank a full power hit from All Might himself. The result is the most damage to Deku's body he's ever had from a single attack, and even after Recovery Girl's healing powers are used on him it still results in lasting ligament damage.
- After a Freak Lab Accident, this is the justification for the eponymous Darkman's strength and inability to feel pain.
- The alleged superpower of Mr. Furious in Mystery Men, though it's pretty obviously just him playing it up. Right up until the end, when he finally gets angry enough for it to actually work.
- Used in Rocket Man, when the titular character has to lift a rover that is lying on top of the mission commander. He asks he commander to call him "Mommy" in order to force this response. It works. It also helps that Martian gravity is 1/3 of Earth's.
- The Dresden Files. During Skin Game, Butters speculates that this is all that Harry actually gains from the mantle of the Winter Knight and points out that it's going to take an immense toll on his body over the long term.
- Though since the Mantle also appears to amp up his wizardly Healing Factor, he might actually be able to get away with it.
- In The Zombie Survival Guide, the narrator points out that zombies don't have the mental limits preventing them from using 100% of their muscular power. This makes them very powerful, but prone to injuring themselves.
- In Of Mice and Men, Lenny has super strength presumably as a compensatory byproduct of his mental deficiency.
- In Poul Anderson's The Sensitive Man, the title character has not only this but many other abilities normally displayed only by psychotics. After a rescue in which he is taken for a mutant or an alien, he confesses to this — and how he's about to have a nervous breakdown.
- In The Stainless Steel Rat, Jim once used an experimental drug capable of bringing a person to this state. According to him, he wouldn't have dreamed of using it if not for the fate of the world being at stake.
- In Corpies, this is Zone's superpower (hence the name: he's always "in the zone"). He consistently performs at his physical peak. Unfortunately, it's quickly shown that his body is starting to break down from him overusing his ability (he frequently parkours through disaster areas). The Docs tell him to take it easy, but his job is too important for that.
- In Tom Clancy's works, a drug referred to as "Thor's Hammer" creates this effect in the same way that PCP does in real life.
- Peeps and carriers can apparently invoke this at will, of course they can also live for centuries so presumably they have some sort of Healing Factor too.
- In Emergence, this is a plot point, called "hysterical strength". Candy uses it to extract Adam from a wrecked car. Please note, this is not Worst Aid, since they're in a post-apocalyptic world with no ambulance service and the entire area the wreck is in is on fire, so his survival requires extraction from the car. Later, Adam proves unable to use this ability until it becomes vital. Candy thinks he has an understandable aversion after nursing her through the effects of overuse of "hysterical strength" while she was rescuing him.
- Seinfeld. George plays with this in one episode: he had been faking a handicap for his employer, who provided him with an electronic scooter; later, George accidentally upsets a group of geriatrics, who chase him on their scooters, but since the battery dies, George picks up his scooter and runs with it... right into his employer. Afterwards, George tries to explain what happened by claiming that in desperate times, people have been known to perform feats of superhuman strength, and even uses The Incredible Hulk as an example.
- This is the origin of the Hulk in The Incredible Hulk TV show. Dr. David Banner, physician, scientist, searches for a way to tap into the hidden strengths all humans have because he wasn't able to save his wife in a car accident despite the scientific fact that some people can flip a car when given the proper incentive. It turns out that on those occasions there were solar flares going on, sending gamma radiation into Earth's atmosphere. Banner overexposes himself with gamma radiation but it doesn't seem to have any effect - until later.
- In the Supernatural episode "All Hell Breaks Loose, Part One" (S02, Ep21), this is a Discussed Trope. When Jake first lifts a vehicle off of a guy it was dismissed as "a fluke adrenaline thing", but he realizes he has Super Strength when he bench presses 800 pounds "stone cold calm".
- In Alphas this is Bill's power, he can activate an adrenaline rush at will for five minutes at a time, his heart can't handle anything longer.
- Paranoia: The mutant power Adrenaline Control allowed the user to boost their Strength to superhuman levels for a short period of time, at the cost of serious muscle damage afterwards.
- Red Markets: Vectors, newly infected "zombies" who haven't technically died yet, tend to be very strong and fast because the Blight doesn't care about tissue damage. They only have a couple days before Blight-caused hemorrhaging or bullets kill them at most anyways, and a couple days after that they'll rise again as a shambling Casualty.
- In Disgaea 4: A Promise Unforgotten, this is how Fuka, who is otherwise an ordinary schoolgirl, is able to match her power with the likes of demons. The narrator explains that while this would normally put a huge strain on a human's body, Fuka is so convinced she's in a dream where she's the Invincible Hero, that she can fight at full power with no adverse effects.
- Humans are only capable of using about 65% of their muscles' potential strength (even when hyped up on steroids) due to a biological block, with trained athletes potentially going as high as 90%. Only a few people have gone past this with even fewer reaching full potential. Every one of those situations was a life or death situation, when special hormones such as adrenaline are able to allow us to override the block, hence how people refer to this reaction as "fight-or-flight". The reason why this Defence Mechanism Superpower can only remain as a defence mechanism is because the stress reaction deprives other systems of energy, like for example digestion (hence Bring My Brown Pants) and the immune system (hence why chronically stressed people are more likely to get sick), and also because any amount of exertion above the one-third limit causes our muscles (and even tendons) to tear themselves from the bone, rip themselves apart, or even start to liquefy. Of course, the severity of the damage depends on the intensity of the stressor, how far beyond the limits one goes, and for how long. Oh, and in addition to that, ever punched a wall? Imagine that, but worse. If you hit something hard enough, you're gonna break your own bones and limbs, short-term. Kinda contradicts that point of being about to do things if you break yourself doing it. So evolution fixed the problem.
- Certain hallucinogenic drugs such as PCP create this effect. This is where the stories of people on PCP being completely immune to pepper spray, fighting off a dozen cops at once, and not being stopped by gunshots come from.
- Mental illnesses and disabilities can also have this effect, hence the (admittedly quite rude) term "retard strength."
- Loss of muscle control is also why it's dangerous to try to restrain someone who's having a seizure. Your best bet is to move objects out of the way until they're all right.