No matter what distance you run you need speed. Not just go out and run long slow distance, that is active rest. You have to do intervals at fractions of desired race lengths at a much faster pace. You can do this as soon as you start. Do running drills to help your form and aid your quick twitch muscles. SPRINT and look ugly doing it!!! You need this 1-2 xs a week along with other training sometimes in the same day and after a couple of weeks you will level out and you have to go even more ugly. It is a 3-6 week phase and it gets you on your game and makes you faster. Run down hill for speed, use parachutes and drop the cord and take off, do plyometrics and quick feet sprints. Do it over and over and in time your 630-800 mile will drop alot as will longer events. If you are a sprinter bang out fast sprints, do dead starts, walking starts and jogging starts into a short sprint and improve. The same rules apply for weights, yes lift for strength but also do real fast reps. TUne in next time and get your butt in shape!!!