What is VO2 max?

If you follow endurance sports (like distance running, for instance), you’ve probably heard the term “VO2 max” thrown around. You know, like when everyone gathers in the bar to watch the Tour de France and the know-it-all chugging Stella Artois at the end of the bar makes some comment like, “Well, Lance Armstrong has a VO2 max of 85 so clearly he’s superior to the likes of those in this bar,” and everyone in the bar kind of murmurs and nods in agreement.

Of course what everyone is thinking, but no one will admit is, “85 what?”

You see, no one actually knows what VO2 max is. That’s why I spout some gibberish about VO2 max to my high school cross country runners when they start complaining about their workouts. They get confused and they usually shut up.

For the record, Lance Armstrong’s VO2 max at his peak was 85 ml/kg/min.

Still not exactly crystal clear is it?

Let’s back up. VO2 max, often called “aerobic capacity” is the maximum capacity of a person’s body to transport and use oxygen during exercise. So, in our example, Lance Armstrong was able to use 85 milliliters of oxygen per kg of body mass per minute. If Lance weighed 75 kg (165 lb), he would consume 6450 mililiters (about 6 1/2 liters) of oxygen per minute. Is that good? Yes. The VO2 max of a sedentary individual is around 30 ml/kg/min and the highest ever recorded VO2 max value was 96 ml/kg/min. Although it’s not the only factor in determining success in an endurance athlete, it is clearly important.

How is VO2 max measured?

Measuring VO2 max is done through a very complex test (generally on a treadmill or a stationary bike) where the intensity of exercise is incrementally increased while the amount of oxygen the subject is using is measured. Generally, oxygen consumption is linearly related to the intensity of the effort. That is, the higher the exercise intensity is, the more oxygen the subject will consume. At some point, however, the subject’s oxygen consumption will cease to increase, despite increases in exercise intensity. The oxygen consumption at that point is the subject’s VO2 max.

Unless you’re an elite athlete, you’ll probably never have your VO2 max tested. You should be thankful. As you can probably imagine, the test involves quite a bit of discomfort for the subject. (Read about Beth Risdon’s testing here.) You can actually estimate your VO2 max by taking your maximum heart rate, dividing it by your resting heart rate and multiplying the result by 15. (But finding your maximum heart rate isn’t very fun either.)

Your VO2 max will vary quite a bit throughout your life. Your level of fitness, altitude at which you’re living, age, gender and genetic factors all affect your VO2 max (in addition to performance enhancing drugs as Lance has admitted since this article was originally written). You really don’t need to know your exact number. You just need to know that whatever it is, you can improve it through training. For now, you’ll just have to be satisfied with knowing what Stella Artois man is talking about so that you can knowingly retort that Miguel Indurain’s VO2 max was 88 at his peak.