Endurance · 3 min read

What Is VO₂ Max Testing and Who Is It For?

VO₂ max is the maximum volume of oxygen your body can consume and utilise during intense exercise. It is one of the most widely used markers of aerobic fitness — and one of the most frequently misunderstood.

By Chris Gkoufas, DVOTION ·

What VO₂ max actually measures

VO₂ max represents the upper limit of your aerobic system. When you exercise at very high intensity, your body needs more oxygen to produce energy, and at some point oxygen uptake stops rising even though the workload keeps increasing. That levelling-off is the classical definition, but it is not reached in every test — with the ramp protocols in normal use a plateau often does not appear at all. Where it does not, the highest value recorded is a VO₂ peak rather than a confirmed maximum, and a report that does not say which of the two it is has skipped the question.

A higher VO₂ max generally means a larger aerobic capacity — the ability to sustain higher intensities before the body shifts to relying predominantly on anaerobic energy systems. But VO₂ max alone does not tell you how to train. That requires understanding where your lactate thresholds sit relative to your ceiling.

Why blood lactate testing is essential alongside VO₂ max

Lactate threshold testing shows at what intensity the body starts producing lactate faster than it can clear it. This threshold — sometimes called the anaerobic threshold or LT2 — is one of the strongest predictors of endurance performance.

An athlete can have a high VO₂ max but a relatively low lactate threshold, meaning they cannot sustain efforts near their ceiling for long. Another athlete with a slightly lower VO₂ max but a higher threshold relative to their max can outperform them over longer distances.

This is why the two are offered as separate assessments. The VO₂ Max Test (£200) establishes the ceiling and both ventilatory thresholds from gas exchange alone, with no blood sample. Endurance Performance Profiling (£300) runs a progressive lactate profile first and the maximal test afterwards, so both lactate thresholds are measured directly rather than inferred from breathing. The VO₂ number is only part of the picture either way.

What sweat rate testing adds

Sweat rate testing measures how much fluid the body loses per hour during exercise. This is relevant for training session duration, race-day hydration planning and understanding individual variation in heat response.

Two athletes can lose vastly different amounts of fluid at the same intensity. Without measuring it, hydration strategies are guesswork.

Who benefits from VO₂ max testing

VO₂ max testing is most useful for athletes whose performance depends heavily on sustained aerobic output. Runners, cyclists, triathletes, HYROX athletes, rowers and team-sport athletes all benefit.

It is also highly relevant for anyone who has been training for a while but is unsure whether their training zones are accurate, or who wants a measured figure for where their endurance ceiling sits and how to raise it.

What the test does not give you

A VO₂ max test gives you data and training direction. It does not give you a full training plan. It tells you where you are, what your thresholds are, and what your training zones should look like. Turning that into a structured plan is the work of coaching — which DVOTION offers separately.

Frequently asked questions

How is VO₂ max measured?

Using a metabolic analyser such as the KORR CardioCoach Max, which measures oxygen and carbon dioxide exchange through a mask during a progressive exercise test.

Is VO₂ max the only thing that matters for endurance?

No. Lactate threshold, running economy, aerobic efficiency and training history all matter. VO₂ max is the ceiling — but thresholds and efficiency determine how much of that ceiling can be practically used.

How often should you retest VO₂ max?

Every 3–6 months is typical for athletes in structured training. Retesting shows whether the aerobic system is adapting and whether zones need updating.

References

  1. Midgley AW, Bentley DJ, Luttikholt H, McNaughton LR, Millet GP (2008). Challenging a dogma of exercise physiology: does an incremental exercise test for valid VO2max determination really need to last between 8 and 12 minutes?. Sports Medicine 38(6): 441–447. doi:10.2165/00007256-200838060-00001
    Supports: That a valid maximal test does not have to last between eight and twelve minutes, which is why no fixed duration is promised.
  2. Midgley AW, Carroll S (2009). Emergence of the verification phase procedure for confirming 'true' VO2max. Scandinavian Journal of Medicine & Science in Sports 19(3): 313–322. doi:10.1111/j.1600-0838.2009.00898.x
    Supports: The limits of the traditional secondary criteria for confirming a maximum, and the verification bout proposed in response.
  3. Beltz NM, Gibson AL, Janot JM, Kravitz L, Mermier CM, Dalleck LC (2016). Graded exercise testing protocols for the determination of VO2max: historical perspectives, progress, and future considerations. Journal of Sports Medicine 2016: 3968393. doi:10.1155/2016/3968393
    Supports: Background on incremental protocol design — stage length, workload increment and total duration — and how those choices affect the result.
  4. Poole DC, Jones AM (2017). Measurement of the maximum oxygen uptake V̇O₂max: V̇O₂peak is no longer acceptable. Journal of Applied Physiology 122(4): 997–1002. doi:10.1152/japplphysiol.01063.2016
    Supports: That oxygen uptake does not plateau in every test, and what follows for whether a result may be called a maximum.
  5. Jamnick NA, Pettitt RW, Granata C, Pyne DB, Bishop DJ (2020). An examination and critique of current methods to determine exercise intensity. Sports Medicine 50(10): 1729–1756. doi:10.1007/s40279-020-01322-8
    Supports: That a maximum on its own does not set training intensity — the thresholds beneath it do.
  6. Joyner MJ, Coyle EF (2008). Endurance exercise performance: the physiology of champions. The Journal of Physiology 586(1): 35–44. doi:10.1113/jphysiol.2007.143834
    Supports: That the lactate threshold is one of the principal determinants of endurance performance, not a secondary measure.

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