That is a well known form of structured training. It is called "spectator fartlek"
Alas road runners get it easier than us. They can speed up to max then turn the nearest corner then collapse in a heap of puffing out of sight.
When you are going up something the length of some of the lakes climbs, you have to keep it up for another half hour before being out of sight!
http://www.mikkmurray.co.uk - My art and running blog! Go on.. Take a look!