If you have completed a couple of races and you want to improve your personal record (like I do!), here's a basic training you can include in your routine.
It's quite simple. Just do alternating fast and slow runs, incrementing your time by 1 minute, from 1 to 5 minutes.
1 min fast / 1 min slow
2 mins fast / 2 mins slow
3 mins fast / 3 mins slow
4 mins fast / 4 mins slow
5 mins fast
As with other exercises, remember to include a warm-up jog and stretch before you start and a cool down jog and gentle stretch after.
For my fellow beginners, you may want to try this on a fairly flat surface (do your hill work separately).
I tried this yesterday with my teammate/coach/timekeeper at Ayala Triangle and we reached 5.93 km in 28 minutes! [25 mins plus 3 mins cool down]. And to think we were even walking the slow parts!
I believe this is a good training to develop your ability to run above your normal race pace and to hold that pace for an increasing amount of time. Mix this up with your long runs / endurance training and you're bound to give the pros a run for their money!
Is this too easy for you? Try this: When you reach 5, go back down to 1!
Good luck! Run for your lives!