What Is VO2max?
With news that Apple watches will soon be able to measure VO2max more efficiently (they say) than ever, you might be surprised that VO2max is even there. This is a measure of your aerobic fitness, and you don’t need a gadget to understand yours.
VO2max, correctly displayed VO 2max is the maximum volume (V) of oxygen (O 2 ) your body can use per minute during exercise, scaled to your body size because larger people will naturally consume more oxygen.
This is considered a good indicator of aerobic fitness because – remember your school biology – your body uses oxygen and food to create a useful form of chemical energy. The amount of oxygen directly depends on the amount of energy produced. Or, to put it simply, the more you work, the more oxygen you need.
Thus, a person who is in good aerobic fitness – say, an elite marathon runner – can do more work (run faster) than someone who does not. As a result, they will absorb a lot more oxygen per minute while running than, say, me.
A typical fit person will have a VO2max somewhere in the 30s and 40s. If you exercise a lot, you can increase this number. Elite cyclists, skiers, and ultra-high-distance runners may have numbers in the 70s and 80s , and some people scored points in the 90s.
Why is a high VO2max good?
To use large amounts of oxygen, you need more than just good lungs. You also need a strong heart and a healthy circulatory system to keep your muscles oxygenated. And you need big muscles that can do a lot of work per minute. VO2max is a way to sum up many important things about cardio training into one prime number.
But it’s important to know that this number isn’t all about fitness or even aerobic fitness. First, it doesn’t make sense to compare your VO2max to that of other people, because factors such as blood volume and muscle mass affect it. In men, as a rule, VO2max is about ten points higher than, for example, in women of the same form. You also usually do not know your exact VO2max.
How can you measure your own VO2max?
The gold standard test is training in a lab, breathing through a tube, where machines measure how much oxygen you actually consume. High-level athletes sometimes take this test if they or their coach wants to know their actual, defined VO2max value.
But we can measure aerobic fitness in other ways, and there are workouts you can do to get an accurate estimate of your VO2max. If you are a runner, you can look at your last run in this chart to find your VDOT, which roughly correlates with your VO2max. (For example, my best time per mile gives me VDOT 38.)
To measure your VO2max from your workout, you need something to help you maximize your aerobic performance. The race does an excellent job of this; so will be such a test as to run as many laps of the track as possible in 12 minutes. I remember doing the test in Phys Ed. class once, where we had to go up and down from a high box as many times as possible. These tests are not pleasant, but their results can serve as a guide to see if you are improving your fitness over time.
What does my watch tell me?
The Apple Health app has a VO2max score hidden among other fitness metrics and has been around for years. (The new Watch software should improve this calculation.) Other fitness tracking watches are trying to estimate this number as well. They seem to usually use your running or walking speed in conjunction with your heart rate to determine how close you are to maximum effort and therefore what your maximum pace will be.
For example, Apple set my VO2max to around 38 when I trained for the spring 2019 half marathon. The VDOT I provided earlier shows 33-34 for my 2:08:28 half marathon finish time . I have never done laboratory tests, so I have no idea which one is more accurate.
The VO2max you get from a fitness watch is a rough estimate, so I wouldn’t think too much about the exact amount you see. But if it seems like your VO2max is constantly increasing as you exercise, there is a good chance you will get better. However, you would notice this on your own, because either you run faster or you can run at the same pace with less effort.