Part 1 of this article detailed what VO2 max is, how its measured, and how it impacts oxygen consumption and, ultimately, running performance. Part 2 of this article explores ways to improve VO2 max so that runners can become more efficient and faster.
Runners can improve VO2 max with mileage and interval training. The former focuses on the peripheral variables related to oxygen extraction and use, like mitochondrial and capillary volumes and aerobic enzyme activity. The latter focuses on the central variables related to oxygen delivery, like stroke volume and cardiac output. For experienced, well-trained runners the intensity of training becomes paramount to improving VO2 max.
VO2 max has been shown to plateau after three weeks of daily training. So the training stimulus needs to increase about every three weeks to improve VO2 max further. There doesn't seem to be any further increase in VO2 max with more than about 70 to 75 miles per week, unless more intense training is added.
High-intensity training (95 to 100 percent VO2 max) is the optimal stimulus for improving VO2 max. Long intervals (three to five minutes) are the most potent stimulus because runners repeatedly reach and sustain VO2 max during the work periods. However, short intervals (less than one minute) can also improve VO2 max, as long as they are performed at a high intensity and with short, active recovery periods to keep VO2 elevated throughout the workout. Figure 1 illustrates what happens to oxygen consumption during an interval workout.
During the first hard work period, VO2 initially rises rapidly and begins to plateau toward the end of the interval. During the recovery period, VO2 decreases. If the recovery period is short (equal to or less than the time spent running, a 1:?1 work-to-rest ratio), VO2 will not decrease all the way back down to its resting value. This is a good thing, because the next hard work period will then begin with the VO2 elevated.
VO2 will then rise again during the subsequent hard work period, to a point higher than during the first work period. If planned right, VO2 will reach VO2 max after a few work periods, which is the goal of the workout. These workouts are difficult, as not only is oxygen being consumed at its fastest rate, but there is also a considerable anaerobic contribution.
Figure 1 – The increase in oxygen consumption (VO2) during an interval workout.