(Undated)  --  Portland ranks among the nation's ten fittest cities.  That's according to the American College of Sports Medicine's most recent American Fitness Index, which bases its rankings on factors such as the number of parks and recreational facilities accessible to residents, bicycle-friendliness, and healthy eating.  The index gives Portland a score of 67-point-nine out of a possible 100, good for a ranking of seventh.  Minneapolis-St. Paul is in first place, with Seattle ranked eighth.