Testing Your Fitness with a Speed and Distance Device
The term VO2max refers to the maximum rate at which an athlete’s body is able to consume oxygen during exercise, or aerobic capacity. A naturally high VO2max is an absolute requirement to achieve elite status in any endurance sport, including running. Proper training will increase any runner’s VO2max significantly, however.
Many of the major physiological adaptations to training serve to increase the athlete’s aerobic capacity. These adaptations include growth of the heart muscle, increased blood volume, and increased concentration of muscle mitochondria (the intracellular sites of aerobic metabolism).
VO2max is a strong predictor of racing performance. Research has shown that VO2max accounts for roughly 70 percent of the variation in race performances among individual runners. Thus, if you are able to run a 5K one minute faster than I can, it is likely that your VO2max is higher than mine by an amount that is sufficient to account for 42 seconds of that minute. But there are other important factors outside the aerobic system, such as running economy, that also affect running performance.
Velocity at VO2max
Any two runners who have the same VO2max do not necessarily run at the same speed at VO2max due to differences in running economy. Running economy is the rate at which your body uses oxygen at any given speed. The higher your running economy, the less oxygen you use to run at any given speed and the faster you can run before you reach your personal maximum rate of oxygen consumption. Having a high VO2max is of little use if your economy is poor, because you won’t be able to reach a very high speed before you hit your personal oxygen limit.
Thus, due to superior running economy, a runner whose maximal rate of oxygen consumption (VO2max) is lower than that of another runner might be able to sustain a faster speed at his or her individual maximal rate of oxygen consumption (vVO2max) than that other runner. If this is so, the runner who has a lower VO2max and a higher vVO2max is likely to perform better in races than the runner with a higher VO2max and a lower vVO2max.
Velocity at VO2max (vVO2max) is the running speed associated with an individual runner’s highest rate of oxygen consumption in testing. Velocity at VO2max is an even better predictor of running performance than VO2max because it accounts for both of the major ingredients of running performance: aerobic capacity and running economy. Therefore, testing your vVO2max is more meaningful than testing your VO2max. Fortunately, whereas VO2max testing requires special equipment and must be done by trained professionals in a laboratory setting, vVO2max is something you can do on your own with nothing fancier than a speed and distance device.
VO2max and vVO2max Testing
VO2max it is determined in the laboratory with a progressive exercise test. While breathing through a tube connected to a machine that measures gas exchange, the athlete runs on a treadmill at incrementally increasing intensity levels until the point of exhaustion. The highest level of oxygen consumption recorded during this test represents the athlete’s current VO2max.
In a standard treadmill VO2max test, the exercise intensity is increased by increasing the gradient of the treadmill. In a vVO2max test, the treadmill remains at a 0 percent gradient and the exercise intensity is adjusted by increasing the speed of the treadmill belt. The runner’s vVO2max is the running speed at which he achieves his highest level of oxygen consumption in this test.
A Simple vVO2max Self-test
If you prefer to avoid the effort and expense of laboratory testing, you can estimate your own vVO2max using a method developed by French exercise physiologist Veronique Billat. The original test uses metric measurements; I will describe an English system equivalent.
After warming up, set the treadmill at a moderate speed and run for two minutes. Increase the belt speed by 1.0 mph and run for two more minutes. Continue in this manner until you reach your estimated lactate threshold speed, and then increase the belt speed by 0.5 mph and run for one minute. Continue increasing the belt speed by 0.5 mph every minute until you cannot run a full minute at a given speed. Stop and cool down. Your vVO2max is the fastest speed you sustained for a full minute.
While this test is easiest to do on a good treadmill, with a speed and distance device you can perform it in any environment that’s conducive to fast running. Use the interval programming function of your device to program the test into your device and then execute it, stopping whenever you reach your limit. It’s up to you to increase your speed by the right amount at each step. You might find this easier if you run by pace (mm:ss/mile) instead of speed (mph). To do this, increase your pace by 30 seconds per mile until you reach your lactate threshold pace and increase it by 15 seconds per mile thereafter.
A second method of measuring vVO2max that was developed by Veronique Billat is even easier to do with a speed and distance device. Through her research, Billat discovered that the average runner is able to sustain his or her vVO2max for approximately six minutes. Therefore you can get a rough estimate of your current vVO2max by warming up and running as far as you can in six minutes. Set the timer on your speed and distance device for six minutes so that you can ignore it during the effort and just concentrate on running hard. When the chime sounds, cool down and then review your workout to find your average pace for the six-minute effort. That pace is your current vVO2max.
Perform a vVO2max test every four to six weeks throughout the training process. You should see gradual improvement. This improvement indicates either that your aerobic capacity is increasing, or your running economy is improving, or both. But it doesn’t really matter how your vVO2max improves. What matters is that it improves, because again, it is one of the best predictors of running race performance.