The Flash’s top speed is Mach 3.3 or 2,532 miles per hour, making him comfortably faster than the fastest jet a human has ever piloted. Running as fast as the Flash in real life is impossible. Since the Flash is a fictional character, just like Hulk, Iron Man, to name a few, the creators of the character are not exactly physicists and don’t take into account all of the problems connected to such a superpower.
He is running over the speed of sound. That sort of speed is achieved by the jet fighters. Not even animals can move that quick. First off, the friction between his feet and the ground would turn into a significant issue. If somebody ran as quick as the Flash, his shoes, or sneakers, would be intensely hot by the time he has finished running. In fact, his feet might be on fire. Friction would likewise influence his clothes. If an individual moved that fast, by the time he or she came to a stop, the individual would be wrapped by flares around the body.
Now, if a human could run that fast all by himself, perhaps with the help of genetic engineering, or a freak accident involving a particle collider, his muscles would have to be powerful enough to achieve amazing speeds, but that’d require a lot of calories, and therefore an amazing metabolism, the bones and ligaments strong enough to work along with those muscles. Leg bones were not designed to allow humans to run at ultrasonic speeds. They’d break apart.
So, it is safe to assume that a real-life Flash would have bones far stronger than human bones. And, if your metabolism allows you to move real fast, it is always possible that your metabolism can also screw up and make you age a lot faster. Maybe a real-life Flash would look 75 by the time he is 25. Suppose we accomplish such a feat with an Iron Man armor. The energy required would require equipment, like a huge battery, that would actually slow down the person due to its weight. And the person using such an armor would need a lot of protection.
Notice that when the Flash falls on the ground, the impact is nowhere is similar what a real-life impact would be like if he was really moving at jet-fighter speed. Losing your balance at such a velocity might be even worse than crashing a Formula 1 car, since inside a Formula 1 car, the impact gets to the car first. Thus, the person running like the Flash would need an armor capable of absorbing an impact even better than any race car could.
And don’t forget that coming to a stop would also be a problem. Notice how Flash is capable of coming to a stop real quickly. With that kind of de-acceleration, you’d retch your innards out. The equipment in the above video will eventually allow us to move faster than normal, known as Bionic Boots. In the future, people may be able to run as fast as a cheetah, which runs around sixty miles per hour. But running as fast as the Flash is impossible.
