Bruce Lee could famously pack a wallop from a short distance—as in one inch. But how on earth did he punch with such power in so short a span? Popular Mechanics breaks things down and discovers that while the physical components of the punch are indeed impressive, the real key to its success lies in the brain. That's where Lee synchronized the myriad body movements required for the punch, "one after the other, linking them like boxcars on a train," explains the Washington Post. As a Stanford researcher elaborates, "When watching the one-inch punch, you can see that his leading and trailing legs straighten with a rapid, explosive knee extension."
That gave his hips plenty of twisting speed, "which, in turn, lurches the shoulder of his thrusting arm forward," says Jessica Rose. The punch culminated with a flick of the wrist just before impact and an immediate pullback once impact occurred; keeping the duration of the punch so short increased its force. Sure, anyone can make an attempt, but brain scans of karate experts taken in 2012 showed that the white matter that manages all this coordination lights up like a Christmas tree during their punches. And it's not innate—it's a skill that improves over time, the brain essentially rewiring itself all the while.