In this post I'm going to cover the following aspects of VO2 Max:
- What it is
- Why it matters (& why the actual number is not that important)
- How it's measured
- What the "normal" ranges are & how that compares to Elite level athletes
- How to improve yours
What does VO2 Max actually mean?
The picture at the top of the page is of my own wrist. So that figure of 61 is what my Garmin has estimated my current VO2 Max to be.
"61 what?" I hear you ask.
Well, lets take a closer look at the term VO2 Max and break it down a little bit:
- V = volume
- O2 = Oxygen
- Max = Maximum or Maximal
Should that be something for an endurance runner or anybody else to get all excited about?
American Heart Association
... VO2 Max is the most important overall correlate of health...and the strongest predictor of cardio vascular disease.
There you have it - if you're interested in being healthy and avoiding heart attacks, then you should probably pay attention to improving your VO2 Max.
What units is VO2 Max measured in?
As oxygen is a gas, gasses are normally measured by volume - in Litres or millilitres. For VO2 Max the usual unit of measure is ml/kg/min that is:
- ml = millilitres of oxygen
- kg = Kilograms of body weight/mass
- min = minute
Put that all together and you get a measure of how many millilitres of oxygen per kilogram of bodyweight per minute you can absorb, circulate and use during exercise.
Why should you care about how much oxygen you can use during exercise or more specifically running?
Endurance running is primarily an aerobic activity. This means that the aerobic energy system is the main player in generating the energy to move your muscles. The aerobic energy system needs oxygen to work (it simply can't function without it). Therefore the more oxygen you can deliver to your working muscles - the more energy you can produce = a fitter and faster you.
Another term that is sometimes used instead of VO2 Max is "Maximal aerobic capacity". I like to think of it as the a measure of the maximum power output of my aerobic engine.
A more powerful engine can result in higher speeds. But only if that power is used efficiently. In running terms that means making sure that you have a strong chassis = bones, muscles, tendons and ligaments. And that you have good running technique. Otherwise that additional power will be wasted and could even damage you. A bit like strapping a jet engine to a hang-glider.
[I've written about the different rates of improvement between your aerobic engine and your runners chassis before here.]
As I mentioned above there's far more involved in running fast than just your ability to process oxygen. Like for example:
- Efficient muscle fibre recruitment
- Force generation & stride length
- Running technique
How do you measure your VO2 Max?
The only way to truly get an actual measure of it is in an exercise laboratory. Where breath samples can be taken whilst you exercise hard on a treadmill.
The process involves wearing a face mask that is connected to devices that measure the amount of oxygen inhaled and carbon dioxide exhaled. The treadmill running starts with a warm up and then the treadmill speed and/or incline are increased. Making it progressively harder for the individual, so they will consume more oxygen as the test goes on.
When the rate of oxygen consumption plateaus - that indicates the maximal aerobic capacity has been reached = VO2Max.
The video below shows just how such a lab test is conducted:
Lactate threshold can also be measured during this type of test. But that involves taking blood samples at regular intervals until it is noted that lactic acid levels increase sharply.
If you don't have the spare cash, access to an exercise laboratory or a GPS watch that gives a VO2Max score. There are other options available to provide an estimate of your VO2Max. The easiest and most widely used of which is the Cooper test.
How does my Garmin assess my VO2 Max?
Your Garmin is obviously not taking samples of your breath as you run. Instead it looks at your heart rate compared with your speed and effort.
To get a VO2 Max reading on your Garmin you will need to complete your profile data. Because it will need to know your gender, age, height, weight and ideally maximum heart rate too. Though it can estimate the latter from repeated running sessions, especially those run at hard effort.
You will also need to run outdoors (Garmin requires the GPS to be activated for VO2Max estimatess) for at least 10 to 20 minutes non-stop and at sufficient intensity. Sufficient intensity is something approaching 70% of your maximum effort.
Firstbeat claim that the algorithms they use to calculate your scores are 95% accurate compared to lab testing. They also say that it learns from you over time and becomes more accurate with use. So, the more you use your Garmin the more accurately it will predict your VO2 Max. Presumably as it will have more data-points for it's calculations.
Despite what Firstbeat claim and I'm sure they have lots of data to back up their 95% accuracy rate - the fact is you just can't get an accurate measure without doing a lab test.
So my advice is to treat the number on your Garmin as a 'best guess' and an indicator of fitness rather than anything like an accurate number.
Another important point to keep in mind is that as with most things your readings will fluctuate. As will your fitness generally. Progress is not linear. Your scores are likely to increase and decrease over time. But, providing that you're training consistently and including the right type/quality of training then the longterm trend should be upwards. So keep an eye on the bigger picture, rather than panicking when your Garmin says your score has dropped after a single run.
What is a good Vo2 Max for my age?
According to Garmin/Firstbeat their 'best guess' of my VO2 Max would put me in the top 1% for my age (52 & three quarters at the time of typing this, in case you were curious).
Their scoring system is colour coded from Red through to Purple:
- Red = Poor
- Orange = Fair
- Green = Good
- Blue = Excellent
- Purple = Superior
Garmin have actually produced some tables on their website to show how these relate to different age ranges. For ease I've included them below:
Garmin VO2Max Tables
20 - 29
30 - 39
40 - 49
50 - 59
60 - 69
70 - 79
20 - 29
30 - 39
40 - 49
50 - 59
60 - 69
70 - 79
Incidentally there are many other similar tables available online that have been compiled from different studies. The tables Garmin use appear to be very similar to those produced by the Cooper Institute of Dallas, Texas.
Why do men have higher VO2 Max than Women?
There are some obvious physiological differences between the sexes, those that influence aerobic capacity are:
- Men generally have more red blood cells, so are able to absorb and transport more oxygen
- Men are also generally larger and have more muscle mass and larger lungs and hearts. These are all key factors for absorbing and transporting oxygen.
- Women have an extra layer of fat (needed for pregnancy). Increased body fat has been correlated to decreased VO2max.
What about Elite level athletes?
It's not uncommon for elite level endurance runners to have VO2 Max scores double that of an average runner.
But as with the average recreational runner - having a higher VO2Max than another elite does not instantly translate into faster race times for them either.
What is the highest Vo2 Max ever recorded?
If you're a bit like me then you may be curious about the extremes in human ability and that tends to lead me to ask questions like this. My research has thrown up some jaw dropping big numbers:
- Men: 97.5 recorded for an 18 year old Norwegian cyclist called Oskar Svendsen in a lab test in Lillehammer in 2012
- Women: 78.6 recorded for Joan Benoit winner of the 1984 Olympic Marathon
There are also some impressively high scores for cross-country skiers of both sexes at 96 and 76.6 respectively.
How can you improve your VO2 Max?
In essence any aerobic exercise performed consistently has the potential to improve your VO2max. Because it will cause your body to respond to the training load by for example:
- Producing more red blood cells & mitochondria
- Increasing the number of capillaries feeding blood to the muscles
- Increase in number and size of bronchioles in the lungs
All of the above will help you to absorb, transport and process oxygen.
However, certain types of running/exercise produce quicker and larger improvements. Basically these are the types of runs that really test your oxygen delivery system and leave you 'breathless'. So, hard efforts like interval sessions and tempo runs.
Beginners also have an advantage over more advanced runners in terms of the size and speed of gains possible. Simply because the lower your baseline score, the more room you have for improvement. Whereas, if you're a bit long-in-the-tooth like me, then squeezing additional gains out of your training is much more difficult as you have less room for improvement before you hit the ceiling of your physical abilities.
It doesn't really matter what your VO2 Max is or what your Garmin or other assessment says (guesses) it is. Unless you're an elite level athlete then I don't consider it's of any real benefit to go to the extent and cost of getting your VO2 Max tested in a lab.