Start and end with a 1/2 mile warmup/cool down and a short dynamic stretching session. The base for the workout will be your real, 5K race pace. The key is consistency for each 400. (i.e. if you are an 8 minute/mile then your 400 should be at 2:00, your 800 at 4:00 your 1600 at 8:00).
