Could humans ever run at supersonic speeds?

Is there a biological limit to how fast humans can run? Or will we all be sprinting like The Flash in future?

- STEPHEN KELLY

There is no firm consensus on how fast The Flash, the DC universe's speediest superhero, can run. One story clocks him at 2,535 miles per hour (over 4,000km/h), for instance, which is faster than most fighter jets. While in Zack Snyder's Justice League, he runs faster than the speed of light, 186,000 miles per second - so fast, in fact, that he violates the laws of physics and turns back time. What is certain, however, is that for the likes of you and me, running at those speeds would be as unlikely as they would be perilous. Our faces would melt, our legs would break apart... I can barely do the 'Couch to 5K' plan as it is.

So how fast can human beings run? For that, we would need to look at the closest thing humanity has to The Flash: retired sprinter Usain Bolt.

In 2009, Bolt set a new world record by running the 100m sprint in 9.58 seconds achieving a top speed of 27mph (43km/h) - at the World Athletics Championships in Berlin. It's a record that is yet to be broken and, according to Mark Denny, a biology professor at Stanford, perhaps never will be.