Interval workouts consist of repeated shorter segments of fast running separated by slow jogging or standing recoveries. This format enables a runner to pack more fast running into a single workout than he or she could with a single prolonged fast effort to exhaustion.
Interval workouts are typically subcategorized as short intervals and long intervals, and are often performed on the track. Long intervals are 600 to 1,200-meter segments run in the range of 5K race pace with easy jogging recoveries between them. They’re an excellent means of progressively developing efficiency and fatigue resistance at fast running speeds.
Example: 1 mile of easy jogging (warmup) + 5 x 1K at 5K race pace with 400m jogging recoveries + 1 mile of easy jogging (cooldown)
Short intervals are 100 to 400m segments run at roughly 1,500m race pace or faster. They boost speed, running economy, fatigue resistance at fast speeds and pain tolerance. Distance runners typically use shorter, faster intervals earlier in the training cycle to increase their pure speed and then move to slightly longer, endurance-based intervals to improve fatigue resistance.
Example: 1 mile of easy jogging (warmup) + 10 x 300m at 1 mile race pace with 200m jogging recoveries + 1 mile of easy jogging (cooldown)