After a few weeks of 400s, I went back to the 8s in the trail at Robin Hill- the goal here was to number one finish the workout, number two stay comfortable the first 5, and number three run the last 5 progressively faster. Mission accomplished, but this was one tough workout. I walked most of the cool-down back to the car, a sure sign that I overextended myself on this one.
I'm convinced that repeat 800s is the one workout that can boost fitness and racing ability (from 5K to the marathon) like no other.
(remember this loop is short- I can't really run those times anymore on a trail- or a track either for that matter)