I have never been on a track. I have, however, tried "sprinting" a couple of times recently, and my goodness, I'm spent after a distance that doesn't seem to be much more than 100 meters, if that. It takes me like 17 seconds.. I'm slow too. I honestly doubt I can keep up a "high" speed (high for me, not compared to others) for 400 meters, probably not even 200 meters... I have a new respect to those who can do 400 meters so fast. I need to start practising longer runs, but still in a range where I can maintain a "high" speed. I hate jogging.