What is VO2 max?

You hear "VO2 max" in training plans and running apps, and it can sound like a number only athletes need. It isn't. It is a plain measure of how well your body uses oxygen when you work hard, and it is one of the fitness numbers Australians look up most.

Here is what it means in everyday language, how a lab would measure it, and how the Thrive Health Band helps the Thrive by Optihealth app estimate it from your resting heart rate and age, so you can watch your own trend rather than chase a chart meant for someone else.

What VO2 max actually is

VO2 max is the most oxygen your body can use during hard exercise, usually written as millilitres of oxygen per kilogram of body weight per minute (mL/kg/min). A higher number means your heart, lungs and muscles can move and use oxygen more effectively when you push yourself.

It is not the same as resting heart rate, and it is not the same as a single workout heart-rate zone. Resting heart rate is how many times your heart beats when you are still. Heart-rate zones describe effort during a session. VO2 max sits above both: it is a fitness capacity number.

Cardiorespiratory fitness shows up in everyday Australian health advice, not only race times. You do not need to be training for an event to care about it.

How a lab measures it (and why few of us ever do)

In a sports lab, VO2 max is measured with a graded exercise test. You walk or run on a treadmill (or ride a bike) while wearing a mask that analyses the air you breathe. The effort ramps up until you cannot go harder. That is the gold-standard reading.

That test is uncommon outside sports labs and clinics. It needs equipment, a booking and a hard effort on the day. So everyday tools often estimate VO2 max from other signals, commonly resting heart rate and age. An estimate is useful for trends. It is not the same as a lab result.

What tends to move the number

A few everyday factors sit behind the figure:

How fit you are. Regular aerobic work (brisk walking, cycling, swimming, jogging) is the usual way people raise cardiorespiratory fitness over weeks and months.
Age. Average VO2 max tends to be lower in older age groups in population tables. That is why age-banded labels exist.
Resting heart rate. All else equal, a lower true resting heart rate pushes an estimate that uses the HRmax-to-HRrest ratio higher. That is why a steady resting reading matters. Our piece on resting heart rate covers what "your usual" looks like.
The day you are having. Poor sleep, illness, caffeine, dehydration and stress can lift resting heart rate for a while, which can pull an estimate around. One odd day is not the whole story.

If you want session effort explained in plain language, see heart rate zones. For how your heart's beat-to-beat timing fits into recovery language, see what HRV is.

How Thrive estimates your VO2 max

The Thrive Health Band has no screen. It sits on a woven TPS strap and records your heart rate through the day and night. Your resting heart rate feeds into the Thrive by Optihealth app on iPhone or Android.

Thrive estimates VO2 max with a published resting-heart-rate formula, using:

Your resting heart rate, preferably from your personal normal over recent weeks when enough readings exist
Your age, to estimate maximum heart rate with a widely used age-based formula

The app then places the number against ACSM-style fitness bands for your age and gender group: Very Poor, Poor, Fair, Good, Excellent or Superior. It can also keep a history so you see whether your estimate is drifting up, down or sideways over time.

A few honest limits, straight from how the feature is built:

It is an estimate, not a mask-and-treadmill lab test
It needs a believable resting heart rate; a rushed reading will not help
It’s designed for general fitness, not for people managing a heart condition. Talk with your GP if that’s you.
Thrive still learns right across your health, not only fitness: sleep, heart, mood, meals and Food Fit, blood tests, medications and supplements, and more

Today's Vitality (0 to 100) brings sleep and recovery, your heart, Today's Load and your mood together, so VO2 max sits beside the rest of your day rather than as a lone badge. Health Fingerprint builds once Thrive has enough of your own signals to describe what is usual for you.

You can ask Ask Thrive questions in everyday language, such as "What has my estimated VO2 max done over the last 30 days next to my resting heart rate?" or "How did my resting heart rate look on weeks when I logged more activity?"

When you want to take the picture to your GP, Ask Thrive can help you pull the trend together beforehand. Our article on using Ask Thrive before a GP appointment shows how. If you would like someone else to see selected information, Thrive Loops lets you share selected information with a participating trainer, health professional or someone you trust. You decide what to share and with whom, and you can change or revoke access at any time.

Thrive isn't a diagnosis, and it doesn't replace your GP. It gives you an estimate of your fitness trend to talk through together to talk through together.

Before you buy

You'll need a compatible iPhone or Android phone, because the Thrive app is on the Apple App Store and Google Play, in Australia and eight other countries. The app stores are only for downloading the app, though; they aren't where you buy the Band or a Plan. You can buy at thrivehealthband.com, or at a participating World Gym Australia location or health and wellness clinic.

The Thrive Health Band is A$660 for the first year under the launch offer. That includes the Band, which is yours to keep, and 12 months of the Thrive by Optihealth app, My Health on the web, Health Fingerprint, Ask Thrive, Thrive Loops and your data, paid once upfront. Prices are in AUD and include GST. Free Australia-wide shipping during the launch offer (usually A$14.99).

Nothing renews automatically. After your first year, you can get a new band plus 12 more months for A$660, or keep your band and renew the Thrive Connected Plan for A$240 a year, or A$29 a month with no lock-in.

You're also covered by a 12-month Thrive Care Warranty, and consumer guarantees under Australian Consumer Law always apply. See Returns if something is wrong with your purchase.

Common questions

Is a higher VO2 max always better?

A higher number usually means stronger cardiorespiratory fitness for your age group, but the useful part is your own trend over time, not a one-off comparison with a stranger online.

Does Thrive run a lab VO2 max test?

No. Thrive estimates VO2 max from your resting heart rate and age. A true lab test needs a graded exercise session with gas analysis.

Where does resting heart rate fit in?

It is the main daily signal behind Thrive's estimate. A steadier personal normal for resting heart rate makes the estimate more useful. See resting heart rate explained.

For more answers, see Questions.