To successfully reach your peak running performance you need to train a number of different muscle, energy and central nervous systems including your VO2 max, vVO2 max, lactate threshold, endurance, speed, strength and neuromuscular conditioning. It's very difficult if not impossible to train all of those systems with just one type of workout. That's where periodization comes in. Periodization is a term that refers to breaking down your training cycle into a sequence of periods or blocks that emphasize a specific or group of specific training goals. There are a number of different periodization techniques you can use to meet your running goal. Here are some articles, tips and information on periodization for runners.