Many people struggle to run a mile; others can knock out a 10K on a whim. A few brave souls take on "ultramarathons" — races longer than 26.2 miles (42.2 kilometers). But how far can a human run ...

News 9's race analyst and trainer Mark Bravo joined News 9 Friday to share tips on preparing for a long run such as the Oklahoma City Memorial Marathon, which is coming up in April.