>Running 101>Advice on Fartlek please?
My .02 is that fartleks should be a bit more relaxed than an interval session. You should finish feeling more energized than exhausted. Usually the first few tries you end up going too fast on your pickups and wind up suffering a bit at the end. It takes practice, but it's good training for regulating your pace by feel versus needing external cues such as mile or km splits to know if you're going too fast.