VO2max for runners: what it is, what is good, and how to improve it

Buy a running watch and it will hand you a VO₂max estimate within a week. Runners obsess over the number, chase it, and compare it. Yet most of what people believe about VO₂max is half right. It is genuinely important, but it does not work the way the hype suggests, and on its own it is a poor predictor of how fast you will race.

What VO₂max actually measures

VO₂max is the maximum rate at which your body can take up and use oxygen during intense exercise, expressed in millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). It is, in effect, the size of your aerobic engine. Bassett and Howley (2000), in a foundational review, concluded that in healthy people VO₂max is limited mainly by the cardiovascular system’s ability to deliveroxygen to muscle, not by the muscle’s ability to extract it. Training gains come largely from a bigger maximal cardiac output, that is, a stronger, higher volume heart stroke.

Why VO₂max alone does not predict your race

This is the part most runners miss. Distance performance rests on three pillars, not one: VO₂max (the ceiling), the fraction of that ceiling you can sustain at your lactate threshold, and running economy (how much oxygen you burn at a given pace). Bassett and Howley (2000) note that velocity at lactate threshold, which integrates all three, is the single best physiological predictor of distance performance.

Running economy explains why two runners with identical VO₂max values can race very differently. Barnes and Kilding (2015) document wide variation in the oxygen cost of running across athletes, and among well trained runners economy often becomes the bigger differentiator. A large engine that burns fuel inefficiently loses to a smaller engine that sips it.

What counts as a good VO₂max?

Numbers help here. Recreational adults typically sit well below elite values. Elite male distance runners usually land around 70 to 85 ml/kg/min. In a verified cohort of 22 male United States Olympic Trials runners, Morgan and Daniels (1994) measured an average of 75.8 ml/kg/min. Elite women generally run lower than elite men, broadly in the region of 60 to 75 ml/kg/min. If your watch tells you 50, that is a respectable recreational value, not a problem to fix.

One uncomfortable finding from the same elite data: among the very best runners, a higher VO₂max often comes packaged with a slightly higher oxygen cost of running. The body tends to trade some economy for a bigger engine. It is another reason the number alone tells you less than people assume.

How trainable is it? The genetics question

VO₂max responds well to training, but not equally for everyone. The HERITAGE Family Study (Bouchard et al., 1999) put 481 sedentary adults through 20 weeks of identical training. The average improvement was meaningful, but responses ranged from almost nothing to gains of more than a litre per minute. The trainability of VO₂max was roughly 47 percent heritable. In plain terms, your genes shape not just your starting point but how much you improve. If a programme works wonders for a training partner and less for you, this is part of why.

The training that actually raises VO₂max

The strongest single piece of evidence is Helgerud et al. (2007). With total training work held equal, four by four minute intervals at about 90 to 95 percent of maximum heart rate, with three minute recoveries, improved VO₂max by roughly 7 percent over eight weeks. The same work performed at lactate threshold or at an easy 70 percent of maximum produced essentially no change. Intensity, not just volume, drives the ceiling upward.

Two meta analyses back this up. Bacon et al. (2013) found high intensity interval training raised VO₂max by around half a litre per minute on average, with longer intervals producing the biggest gains. Wen et al. (2019) reported that long intervals of at least two minutes, higher session volumes, and programmes of four to twelve weeks produced significantly larger gains than shorter formats or moderate continuous training. Midgley et al. (2006) concluded that, for trained runners, the most reliable stimulus is accumulating time at roughly 90 to 100 percent of the velocity that elicits VO₂max.

Where threshold work fits in

The fashionable Norwegian method, described in a peer reviewed model by Casado et al. (2023), pairs a large base of easy running with several lactate guided threshold interval sessions per week and a single weekly VO₂max session. The logic is that threshold work lets athletes accumulate a lot of high but sustainable intensity with relatively little fatigue, while the one hard VO₂max session keeps the ceiling high. The base of easy volume underpins all of it, which is exactly why Zone 2 training and VO₂max work are partners, not rivals.

How much, and how fast?

Be realistic. Untrained people often improve 10 to 20 percent or more over a structured 8 to 12 week block. Trained runners gain far less because they are nearer their genetic ceiling, and chase low single digit percentages. Meaningful change is usually visible within four to eight weeks. After that, the engine matters less than what you do with it, and economy and threshold become where the next minute of race time is found.

Frequently asked questions

Related reading: How accurate are race time predictors? An honest look at the research.