Even assuming the <PERSON> got all the powers he needed, super stamina, near indestructable body, etc, A real-life <PERSON> running at hundreds of miles an hour would actually have several weaknesses just from the laws of physics.
IRL, there are a few major problems with running super fast. Many of these problems would severely limit a speedster superhero. Both Friction and Inertia would be his enemies.
Pants on Fire - In reality, I doubt any material is both flexible enough to withstand moving at hundreds of miles an hour, and frictionless enough not to burst into flames. The <PERSON> will have to slow down if he wants to keep his clothes on.
Cool-Aid Man Stops - Remember how the Cool-Aid Man breaks through the wall to hand out cool refreshing sugar-water. Unlike in the comics, where the flash can run up buildings, inertia means he'd likely run through the wall, shattering it or himself into pieces.
Skid Marks - Running straight is easy, but every time he turned, he'd leave deep indentions in the grass, broken pavement, and the like. It would be pretty easy to follow him to his secret crime lab.
Turning on a Dime - Similar to above. The Flash would not be able to turn quickly given his inertia and small mass. Simply block stright-aways and the Flash has to go MUCH slower. 300
Throw in some trip wires and obscured holes and you'll probably be able to nab yourself a speedster.
Follow the Fire (and Noise) - Running super fast will create friction (i.e. heat) with the air, even if the suit is frictionless (see #1). He'd also likely sound like a sports car zooming past. A heat-guided missile + some other smarts would probably have no problem locking onto him.
Calorie Deficit - Marathon runners burn about 2,500. . That's a few minutes of running for the <PERSON>. Simply pay off pizza and burger joints to find out who the skinny guy is that eats 5 burgers a day, and you'll unmask your hero.
How do you say Adamantane - The Flash will need a special suit + special communications devices that work at his speed. Those will be one of a kind. Simply follow orders of exotic materials until you find the crime lab. 500