I found these two articles very interesting. I think the "Tyranny of the comfort zone" article might provide some clues to Sugar's great performances over the past few weeks. Running quick and short has probably taken him out of his comfort zone after a couple of cycles of marathon training and the results are obvious.
The tyranny of the comfort zone
The other article provides some clues on what those of us who are marathon training can do to maintain our speed. I was doing the short hill sprints but let them lapse when I started doing other speedwork. Time to re-incorporate them I think, especially if I am going to run the 10km at the Fremantle Fun Run on 4 October.
Don't let marathon training steal your speed