The Fitness Pacer Test starts deceptively slow but ramps up quickly. Each beep demands faster sprints with less recovery time. At first it feels manageable, but fatigue sets in faster than expected.

A US Marine and a firefighter squared off in the brutal Pacer Fitness Test. Both professions demand elite conditioning, but ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. (NEXSTAR) — Kids, lace up your sneakers and ...