That's not some "unseen potential". We know why that works: our muscles actually have quite a bit more power than our structural design can handle. The women who do that sort of thing also crack vertebrae and damage the muscle and tendons and basically permanently reduce their health and capabilities for a few seconds of strength. The muscles themselves are controlled by a part of the brain that normally suppresses the activation of all the muscle cells at once. It's just evolution at work: you can't perform acts of strength that would damage your ability to survive and reproduce, unless your brain decides that you absolutely must do so right this second or you will either die or your children will die.