IS A VO2 MAX TEST WORTH IT?
You would be forgiven for thinking that you need to do a VO2 max test in order to know your VO2 max, so that you can then train it. This is logical but flawed thinking. The truth is that you do NOT need to know your VO2 max in order to improve it! As a man who has done thousands of VO2 tests in my time, I’m happy to tell you why:
A TRUE VO2 max test wrecks your day. Going to your max usually means collapsing in a breathless heap next to your bike or flying off the back of a treadmill. For very fit and very motivated athletes this is sometimes worth it and desired but if you are just starting out then why woudl you want to do that especially if you don’t NEED to do that! Plus in lower quality labs, most VO2 “max” tests are in fact VO2 “peak” tests as they often stop before you hit max! So you pay your money, do a test and still not know your VO2 max.
In theory, the test gives you a maximum heart-rate reading and from there you can train at various %’s of that max for different benefits, but since you don’t hit max heart-rate in the test and the truth of training zones is that they are far more person specific than a %formula might give, again the test is redundant for this purpose
Furthermore, they typically want you to be fasted before your VO2 max test and for many people this is metabolically stressful (actually raises respiratory quotient), lowers energy and negatively affects the test results! VO2 data will change dramatically with what you eat or don’t eat prior to the test.
The #1 reason to do a lab test is to get your custom heart-rate training zones and a VO2 test is too short (at a total of 10 to 15 minute long) to achieve this. It takes about 3 minutes at any intensity for the HR to stabilize and the VO2 test is a constant “ramp” so identifying precise heart-rates is missed. Furthermore, they often use an incline for the treadmill test so unless you are an uphill walker the biomechanics that you have trained to use as a runner are negated, again leading to false results.
So you’d be forgive for thinking that I am against VO2 tests all together BUT the truth is I use them everyday, just for a different reason …..
The main thing I want from a VO2 test (and I’ll discuss this more later) is to know how much fat and how many carbohydrate calories the athlete burns per hour at various intensities. This can help food and fuel planning. The problem is that most VO2 machines (think VO2 master, Calibre, etc) in use today do NOT measure both oxygen and carbon dioxide so you can’t accurately get this information. You need a real lab with a great metabolic cart and a smart sports scientist running the test to find this, not some teenager technician in your local gym or physical therapy office! Luckily for you in my lab I use the latest, most advanced analyzer that truly MEASURES all data - no formulas involved - and I run your test for you in person.
As you probably know, I suggest that LACTATE TESTING is the way to go to get your training zones, find your ZONE 2 and Lactate & Steady State Thresholds and know what training to do which I tell you more about in this Video and/or Blog article. Once I have your lactate data, I then use a VO2 max tests for 2 specific reasons:
1. When I am looking for a few % more from a talented or already well-trained athlete
2. When I want to know substrate use (think “fuel mix”) to help with pacing and fueling strategies for the long-distance athlete (such as marathon, IRONMAN, Ultra) OR what balance of macronutrients in a meal affect fuel use so we can better plan meals and pre-race foods.
Understanding point #2 requires a little deeper knowledge ……
All human engines are “hybrids”, in that they burn a mixture of fat and carbohydrate depending on the exercise intensity. Fat is the body’s #1 fuel source as it delivers more than twice the energy than carbs, however making Fat available to burn as fuel takes longer. Therefore, it is used for primarily lower intensity fueling, whereas fast burning Carbs fuel shorter, more powerful efforts. A well-tuned engine will burn fat for as long as possible and spare its carbohydrates until the highest intensities. What you eat affects how you burn your fuels. If you put diesel in a Ferrari it won’t run that well! The main advantage of a VO2 test is finding out the number of carbohydrate calories that you burn per hour at various intensities. From here you can plan fueling and pacing much more clearly. (see graph below).
How can I estimate my VO2?
It’s fair though that you want some sense of comparison as you get fitter to know if you are improving your “top end” or VO2 max. This is easy. Most heart-rate monitors will be tracking this using their proprietary algorithms. Whether or not they are super accurate is debatable BUT they will show you trends and as long as yours are trending up then you can be happy. Another way is to do a repeatable running timetrial called the Cooper 12 minute test. Simply run as far as you can in 12 minutes and use this formula : VO2 max = (22.351 x distance in kilometers)
You can also look at your endurance PR’s. If for example, you 5km or 10km run time or your 10 mile or 40K TT times are improving then you can be pretty sure so is your VO2 max.
So, in summary, yes VO2 is important and yes we want to train and maximize it BUT there is a right time and a wrong time to work on your VO2 along your athletic journey.