Lactate, VO2 Max, or Combined: Which Test Should You Book?

If you have decided to get tested, the next question is which test. We offer three: a lactate threshold test, a VO2 max test, and a combined profile that does both in one session. The lactate and VO2 tests are the same price. The combined is the top tier.

Here is the short version. If you want your training zones dialled in, book the lactate test. If you want to know your aerobic ceiling and your efficiency, book the VO2 max test. If you want the complete picture, including the one number neither single test can give you, book the combined. Below is how to know which of those is you.

This post is about choosing between the tests, not explaining the underlying physiology. If you want the science first, read Your Zone 2 Heart Rate Is Probably Wrong and Why Your VO2 Max Isn't Improving, then come back.

Book the lactate test if you want your training zones right

The lactate threshold test measures blood lactate across a graded ramp and gives you your two thresholds, aerobic and anaerobic, in pace or power and in heart rate. Those two numbers define your training zones directly.

This is the test most endurance athletes actually need day to day, because zones are what you train and race by. If your goal is to stop guessing whether your easy runs are easy enough, to pace a race properly, or to know the exact intensity your intervals should hit, this is the test that answers it. It is the gold standard for thresholds because it measures the metabolite directly rather than estimating it, which is why we use blood rather than breathing for this, as we explained in Lactate vs Ventilatory Thresholds.

Book the lactate test if: you are training by heart rate, pace or power zones and you want them set to your physiology rather than a formula. For most runners, cyclists and Hyrox athletes, this alone is a big step up from a watch estimate.

Book the VO2 max test if you want your ceiling and your efficiency

The VO2 max test uses gas analysis to measure your maximal oxygen uptake, the size of your aerobic engine, along with your running or cycling economy, which is how efficiently you use oxygen at a given pace or power.

This test answers a different question from the lactate test. It does not tell you where your thresholds sit. It tells you how big your ceiling is and how economically you run or ride beneath it. Two athletes with the same threshold can have very different ceilings, and two athletes with the same VO2 max can differ enormously in economy, which is often what separates them on race day.

Book the VO2 max test if: you want to benchmark your aerobic ceiling, track it across a season, or understand your efficiency. It is priced the same as the lactate test, so the choice between the two is purely about which question you want answered, not cost.

Book the combined profile if you want the complete picture

The combined profile runs both tests in a single session, and it gives you more than the two tests stacked together. Because it measures your thresholds and your VO2 max at the same time, it produces your fractional utilisation, the percentage of your VO2 max you can actually hold at threshold. That single number is arguably the strongest predictor of endurance performance, and neither single test can produce it on its own.

You also get your full economy profile alongside it, so the combined test is a complete athlete profile: ceiling, thresholds, the fraction of the ceiling you can use, and how efficiently you use it. For a serious athlete, this is usually the one worth the extra, because fractional utilisation is where the real insight lives. Two athletes with identical VO2 max values can perform completely differently depending on what fraction of it they can sustain, and this is the only test that measures that.

Book the combined profile if: you are training seriously toward a goal and want the full physiological picture rather than one slice of it, or you want a complete baseline to track everything across a season.

What about cycling and running?

All three tests come in both running and cycling versions. The running tests are done on a treadmill, the cycling tests on a bike. If you are a triathlete or a Hyrox athlete who also rides, the cycling and running thresholds are not the same, so test in the discipline you are training for, or test both if your sport demands both.

Which one, in one line

Most people who want better training zones should book the lactate test. People who want their ceiling and efficiency should book the VO2 max test. Anyone training seriously toward a goal, who wants the complete profile and the fractional utilisation number that predicts performance better than anything else, should book the combined.

If you are still not sure whether you need testing at all, start with Do You Actually Need a Lactate Threshold Test?, which is honest about who benefits and who should wait.

We test at Team Rees in Caerphilly and KORE in Newport, with Cardiff, Swansea and Bristol coming soon. All three tests, in running and cycling versions, are bookable now.

See current pricing and book your test.