Determining speed (sprining vs distance)

If you're running from a bear, you are the one who will be caught.

If you were being chased by a sprinter he'd ALWAYS catch you. You on the other hand have to setup an arbitrary distance to which you can catch him, major difference there.

That reminds me of the Ben Johnson story years ago he got robbed by some kids in the Middle East somewhere and he chased them but couldn't catch them, what a bummer that must have been.

What about running from a cop? You will have a headstart... I'd say a quartermiler or 800 guy would be best at running from a police officer. A cop with decent footspeed might be slightly gaining at first, but would quickly fade, and after 20 sec. or so the runner would start pulling away.

Of course, the K-9 unit would be another story, you would need a blunt weapon to punch the dog with. Not even Asafa Powell can outrun a german shepherd