What Is a Good VO2 Max? Estimating Yours Without a Lab

Most people meet VO2 max through a watch. It appears one morning as a two digit number with a small arrow beside it, and the obvious question is whether it means anything. It does, though not in the way the arrow implies.

What the number is measuring

At maximum effort your heart, lungs and muscles pull oxygen out of the air and burn fuel with it. VO2 max is the ceiling on that process. The units are millilitres of oxygen per kilogram of body weight per minute, so a 70 kg runner scoring 45 is consuming roughly 3,150 ml of oxygen every minute when fully extended.

It is not a measure of skill. Two runners with identical scores can finish a 10k five minutes apart because one of them wastes less energy at speed.

Why the per kilogram part matters

Dividing by body weight has an odd consequence. Take that same runner at 78 kg rather than 70 kg, with no change at all in absolute oxygen use. Now it is 3,150 divided by 78, which is 40 instead of 45. Losing eight kilos moves the score five points without a single extra training session. That surprises people, especially after a strict diet month.

Estimating it without a lab

The 12 minute run

Warm up properly, then cover as much ground as you can in 12 minutes on a flat track. The estimate is the distance in metres minus 505, divided by 44.7. Run 2,600 m and you get 2,095 divided by 44.7, which is 46.9. Run 2,000 m and it falls to 33.4. The usual failure is going out too hard and walking the last three minutes, which can understate the result by five points.

The resting heart rate shortcut

The gentler version is 15.3 multiplied by your maximum heart rate divided by your resting heart rate. A 40 year old with an estimated max of 180 and a resting rate of 55 gets 15.3 times 3.27, or about 50. Push the resting rate to 70 and the same person scores 39. Fifteen beats of resting heart rate is worth roughly eleven points here, which is why steady endurance work moves this estimate quickly. If you want the heart rate side of it in more depth, our piece on heart rate zones explains where those thresholds come from.

Using the VO2 max estimator

The estimator asks for age, sex, weight, and either a resting heart rate or a test distance.

For resting heart rate, count before you get out of bed. Thirty seconds doubled is close enough, and averaging three mornings smooths out a bad night. A watch worn overnight reports its own resting figure, usually two to four beats lower than a hand count, so pick one source and stay with it.

Maximum heart rate defaults to 220 minus age if the field is empty. That is a population average with a wide spread, so enter a higher figure if you have genuinely recorded one. For the run test, enter metres rather than laps.

Repeat it a month later using the same method. The direction of travel is the useful part. If you are turning fitness into race targets, the pace calculator converts a goal finish time into the per kilometre splits it actually requires.

Common questions

Is the VO2 max on my watch accurate? It is inferred from pace and heart rate during outdoor runs, so it tracks a trend reasonably and is weak in absolute terms. Hills, headwind and a strap that drops out all skew it. Treat any single reading as give or take five points.

How much can I realistically improve it? Someone starting from nothing usually sees the biggest gains in the first three months. A person already training several times a week might move two or three points across a year. A ten point jump in six weeks is a measurement artefact.

Does VO2 max fall with age? Gradually, from the mid twenties onward, though training slows the decline a lot. A 55 year old running four times a week can comfortably outscore a sedentary 30 year old.

What counts as a good score? It depends on age and sex, so compare within your own band. As a rough anchor, the middle of the range for a middle aged man sits in the high thirties, a little lower for women, and above 50 suggests regular endurance training.