WHEN YOU FIRST get into running, your routine probably looks something like this: Lace up the best running shoes you own, hit a quick warmup, and then hit the road for a set time, distance, or route.

When Alan Culpepper was one of best runners in the country, with an incredible range, going from 3:55.1 for the mile to 2:09:41 in the marathon, a workout called a “tempo run” was one of the mainstays ...