Michael: You might’ve heard some version of this story before: A kid is trapped under a car, and, in a panic, his mom somehow lifts the car up to get him to safety. This sounds like something straight out of a movie, but it actually does happen! So what really goes on in these life-threatening moments? Can anyone summon superhuman strength?

Well, kind of. Some biological changes can give you a boost in extreme situations, but there’s a limit to what your body can do. When you’re stressed or terrified, your brain signals your adrenal gland to release hormones like cortisol and adrenaline into your bloodstream. Cortisol can increase the amount of glucose in your blood, and adrenaline can pump up your breathing rate and heart rate to shuttle more oxygen around your body, including to your muscles. And this can give you an energy boost!

There’s also some evidence that your brain releases chemicals called endocannabinoids when you’re under stress, which can reduce the pain you feel. Now, scientists can’t exactly create high-pressure, dangerous situations in a lab to study all this. Like, y’know, trapping a volunteer in a room with an aggressive bear or something.

So it’s hard to know how much of an effect these chemicals have on pushing your body to its limits. And figuring out what those limits are is even harder. Scientists who research human body movement, called kinesiologists, have tried to study competitive athletes to get a better idea of these limits.

It’s thought that your body doesn’t usually generate all the force it’s capable of. Partially because it’s more efficient — after all, you don’t need every muscle cell in your arm to pick up your phone and send a text. But it’s also a way your nervous system makes sure you don’t injure yourself by pushing your muscles too hard and damaging tissues.

In a life-or-death situation, or a high-pressure situation like the Olympics, your brain seems to throw caution to the wind. And stress responses cause your body to use more energy. Still, it’s important to remember your body has its limits: If you can only lift 50 kilograms on a good day, you probably can’t pick up a 2000-kilogram car no matter what.

Plus, those sensational news stories can be kind of misleading. Sure, maybe someone did pick up a car to save their kid, but they probably didn’t dead-lift the whole thing like Captain America. They probably just lifted one end, which isn’t nearly as heavy.

So while there’s some evidence for bouts of super strength, we’ve still got to separate science from science fiction. So... probably don’t try to stop a train like Superman or anything.

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