The idea that the brain has a sort of block limiting the amount of strength we can demand from our musculoskeletal system at any given point has always fascinated me, but I don’t know if there’s any truth to it.

It’s the explanation i generally hear for seemingly impossible feats of super-human strength like a soccer mom of moderate physical fitness somehow being able to lift a very heavy object off her wounded child.

The reason for this strength limit that I’ve heard is that if we had unlimited access of all our strength we could injure ourselves. Like if I suddenly summoned all the strength in my upper arm I could potentially break my humorous— as I type it sounds silly, but the idea still intrigues me.

There are a few cases of people experiencing bone fracture after non-traumatic seizures, but that’s the closest thing I’ve found to the upper arm example.

The whole thing makes me wonder what sort of applications this could have for strength training. For instance, in powerlifting it’s commonly thought that you shouldn’t train at 100% (you shouldn’t test your strength limits/maximums) capacity very often because the exercise is very demanding on your central nervous system.

And as an amateur lifter, I can confirm that the kind of fatigue from 100% exertion is very different from the fatigue of a demanding workout at 70% capacity or less. In the latter case you need to stretch, eat, and rest. But in the former you just want to take a nap…

So.. is there any truth to this “mental-block” or is it just a myth?