In the previous Run Training posts, I described the tools which runners typically use to improve their running performance. Whether elite or recreational, all runners bodies respond to the training effects of Base Training, Hill Training, Strides, and Intervals. In regards to interval training, many folks just beginning their exercise journey may engage in interval training to increase calorie burn. And almost all sports use some form of interval drills to improve athletes’ aerobic and anaerobic exercise thresholds. So what does interval training involve? Basically, interval training uses measured bouts of hard-easy repetitions to help athletes adapt to higher levels of aerobic and/or anaerobic exercise. For runners, interval training is meting out hard-easy running in bouts measured by time or distance (minutes or meters). Unlike tempo training (comfortably hard effort) interval training involves running at a high level (near red-line) of exertion for a short amount of time, followed by a recovery interval equal to or greater than the work interval. Novice and recreational runners should begin interval training only after they have laid down their base training. While extremely effective to improve a runner’s running form, economy, endurance, and fat-burning, interval training need only be included once a week if the runner also performs other training methods (strides, hills, tempo) in their weekly runs. Read this article from Active.com about interval training. This is an excellent resource which describes the science of intervals together with interval training plans for runners who want to improve their 5K or 10K race times.