You do not need the number to raise the number
As a man who has done thousands of VO2 tests, Gareth is happy to tell you why — plus what he does use VO2 tests for.
VO2 is important, and we want to train and maximise it. There is a right time and a wrong time to work on it along your athletic journey. A VO2 test should really be used to learn about fat use, in conjunction with a lactate test from which you get your training zones.
A true 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. If you are just starting out, why would you want to do that — especially if you do not need to?
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.
It is a poor way to set heart-rate zones
In theory the test gives you a maximum heart-rate reading, and from there you can train at various percentages of that max. In practice you do not hit max heart-rate in the test, and training zones are far more person-specific than a percentage formula might give. Again the test is redundant for this purpose.
The number-one 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 minutes long — to achieve this. It takes about three minutes at any intensity for the heart rate to stabilise, and the VO2 test is a constant ramp, so identifying precise heart-rates is missed.
What Gareth actually wants from a VO2 test
The main thing he wants from a VO2 test 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 in use today — think VO2 Master, Calibre, and the like — do not measure both oxygen and carbon dioxide, so you cannot accurately get this information. You need a real lab with a great metabolic cart and a smart sports scientist running the test, not some teenager technician in your local gym or physical-therapy office.
In his lab he uses an analyser that truly measures all data — no formulas involved — and he runs your test for you in person.
When he adds VO2 after lactate
Once he has your lactate data, he then uses a VO2 max test for two specific reasons.
- When he is looking for a few percent more from a talented or already well-trained athlete.
- When he wants to know substrate use — the fuel mix — to help with pacing and fuelling strategies for the long-distance athlete (marathon, IRONMAN, ultra), or what balance of macronutrients in a meal affect fuel use so meals and pre-race foods can be planned better.
You can watch VO2 without a mask
You can also look at your endurance PRs. If, for example, your 5 km or 10 km run time, or your 10-mile or 40 km TT times, are improving, then you can be pretty sure so is your VO2 max.
So yes, VO2 is important. Yes, we want to train it. The test is not the starting point for most people. Lactate first, fuel mix when it is time.
