Running is endangered. You might find this hard to believe. After all, the number of entrants in your local 10K is surely on the rise, and every Saturday the park is packed with people prancing around in brand new trainers, trying to nurture their chi or look good for their wedding or whatever. Unfortunately, few if any of them are running. They're jogging, a half-hearted fore-aft movement of the legs that, mechanics aside, has about as much in common with running as billiards. And with all the jogging going on out there, actual runners are an increasingly rare breed. (CP+B)