What Pace Should Runners Complete Intervals?
Regardless of the length of the intervals, runners should run them at the speed at which VO2 max occurs (referred to as the "velocity at VO2 max," or vVO2 max), which is approximately 3,000-meter (2-mile) race pace for highly trained runners. If a runner runs two miles in longer than about 10 minutes, however, VO2 max pace will be between one-mile and two-mile race pace. If using heart rate as a guide, runners should come close to reaching their maximum heart rate by the end of each work period. As Figure 2 illustrates, the velocity at VO2 max can also be calculated from VO2 max and running economy tests.
Examples of Specific VO2 Max Workouts
- 5 x 1,000 meters @ vVO2 max with a 1:?1 work-to-rest ratio
- 6 x 800 meters @ vVO2 max with a 1:?1 work-to-rest ratio
- 40 x 200 meters @ vVO2 max with a 1:<1 work-to-rest ratio
If you run 3,000 meters in 8:30, the above workouts would correspond to:
- 5 x 1,000 meters in 2:50 with 2:30 to 3:00 jog recovery
- 6 x 800 meters in 2:16 with 1:45 to 2:15 jog recovery
- 40 x 200 meters in :34 with :17 jog recovery
If you run 3,000 meters in 10:00, the above workouts would correspond to:
- 5 x 1,000 meters in 3:20 with 3:00 to 3:20 jog recovery
- 6 x 800 meters in 2:40 with 2:00 to 2:40 jog recovery
- 40 x 200 meters in :40 with :20 jog recovery
Although VO2 max is considered an aerobic variable, the speed at which VO2 max occurs involves a considerable contribution from oxygen-independent (anaerobic) metabolism, as it occurs at a speed faster than the lactate threshold. This point seems to be lost on many runners and coaches, as this tells us something about the relationship between aerobic and anaerobic metabolism. Although counterintuitive, the fastest rate of oxygen use occurs when there is also a lot of energy being produced without oxygen—the Krebs cycle and electron transport chain are working at their fastest rates only when anaerobic glycolysis is also working. In other words, the fastest aerobic motor occurs when an anaerobic motor is also running.