For the eighth year in a row, Arlington, Virginia, has ranked in the top spot as the fittest city in the U.S. in the American College of Sports Medicine's (ACSM) annual American Fitness Index.

Think of an ancient empire and you’re probably picturing an iconic site like the Acropolis in Athens, or Rome's famous forum.

Does the top 1% feel out of reach for you? In most cases, getting into the top 5% may seem much more manageable. Nationally, ...