How to Increase Your VO2 Max

It used to be that only runners and other endurance athletes knew what VO2 max was. But times have changed. Health influencers like Peter Attia have singled out this once-esoteric metric as a touchstone of fitness and longevity, fueling widespread interest in ways to increase VO2 max. As a running coach, I know a thing or two about this topic, and what follows is my take on what every athlete ought to know about it.

What is VO2 Max?

First, a definition. VO2 max represents the maximal rate at which an athlete is able to use oxygen to power muscle work during intense exercise. Also known as aerobic capacity, this fundamental physiological measurement varies widely between individual athletes, is trainable, and strongly predicts race performance. A 2010 study by researchers at Lynchburg College, for example, found that, within a group of 17 runners, individual differences in velocity at VO2 max (or the speed at which a runner’s rate of oxygen consumption peaked) accounted for 94.4 percent of performance variance in a 16-km time trial. Simply put, to be the best endurance athlete you can be, you need to raise your VO2 max as high as possible.

RELATED: What’s the Best Way to Measure Your Run Intensity?

How to improve your VO2 Max

How is this done? Research has shown that high-intensity interval training is an especially potent tool for elevating aerobic capacity. A study published in the Journal of Strength and Conditioning Research in 2010 reported that just six high-intensity interval sessions completed in a period of two to three weeks boosted VO2 max by an average of 5.5 percent in a group of active young men and women.

Not all high-intensity interval training is the same, though. Three- to five-minute intervals performed at or near VO2 max intensity will have a stronger effect on aerobic capacity, typically, than either shorter intervals done at sprint intensity or longer intervals done at moderate intensity. There are exceptions, however. Scientists at Inland Norway University of Applied Sciences have developed a couple of novel interval workouts—one featuring two-step intervals that toggle back and forth between VO2 max intensity and moderate intensity, the other comprising 30-second efforts just below VO2 max intensity separated by 15-second active recoveries—which allow athletes to accumulate more total time at or near VO2 max within a single session without perceiving it as harder than traditional VO2 max intervals.

RELATED: How to Get Better at Pacing (and Why It’s Worth the Effort)

One might ask: Which workout is the most effective for increasing aerobic capacity? Nobody knows, but my hunch is that doing a variety of different types of high-intensity intervals will generally yield better results than doing the same workout over and over. The physiology behind VO2 max is complex, encompassing everything from capillary density in the muscles to plasma volume in the blood to pain tolerance, so it just makes sense to come at it from a variety of angles.

This brings us to the second proven way to increase VO2 max, which is nearly the opposite of the first: high-volume, low-intensity training. Whereas high-intensity intervals get most of the research attention, we know that spending lots of time at low intensity is essential to maximizing aerobic capacity. It’s no coincidence that the highest VO2max scores are invariably recorded by elite endurance athletes who spend hours and hours training at low intensity every week. A classic 1979 study published in the Canadian Journal of Applied Physiology compared VO2max scores in professional ice hockey players, who do a lot of high-intensity intervals in training and not a lot of Zone 2 work, and elite runners, who do about 80 percent of their training at low intensity, and found that aerobic fitness was 13 percent higher in runners, on average.

RELATED: You’re Not Really Training in Zone 2 (You Just Think You Are)

Further evidence that completing large amounts of low-intensity training is necessary for maximal aerobic development comes from a study that looked at changes in training methods and fitness in elite rowers between the 1970s and 1990s. The biggest changes in training over this span were a 66 percent increase in monthly time spent at low intensity and a 30 percent decrease in time at high intensity. Over the same period, VO2 max increased by an average of 12 percent.

The key takeaways

In summary, if you want to maximize your aerobic capacity, you need to combine large amounts of low-intensity training with small amounts of high-intensity intervals done at or near VO2max. This same combination of training is also the best way to maximize overall running performance, and it’s important to remember that the purpose of training is to set race PR’s, not VO2 max PR’s.

RELATED: The Goal Behind All Goals

Too often, runners fixate on a single fitness component and pursue it in a way that is detrimental to overall performance. An example is fat-burning ability, which, although it does contribute to performance, is not the be-all and end-all of performance, which tends to go down when runners adopt high-fat diets in the name of maximizing fat-burning capacity.

VO2 max is different in the sense that increasing it is never harmful to running performance. However, it is possible to get fitter and race faster without increasing aerobic capacity, and runners who focus on it too much are prone to think their training isn’t working when in fact it is, and to inadvertently self-sabotage by trying to fix what isn’t broken. Now you know everything you need to know about VO2max.