How Long Does It Take to Improve Your VO2 Max? Here’s What Research and Experts Say

Until recently, VO2 max testing has been inaccessible to most everyday athletes. Unless you had an in with an exercise physiology lab, you had to rely on back-of-the-envelope calculations or wearable tech to generate a rough (sometimes, really rough) estimate.

But as more recreational athletes and fitness-minded people express an interest in collecting accurate personal data and tracking health metrics, the market has responded. Some forecasters predict that the global sports science equipment market, which includes the tech needed to measure VO2 max, will grow from $3.2 billion to $5.5 billion in the next eight years.

Already, in most major cities, you can walk into a sports performance clinic and get your VO2 max tested for fitness and longevity, for the price of a new (expensive) pair of running shoes. (Labor Day Shoe Deals lactate threshold Study Says VO2 Max Better Health Marker Than BMI.)

With more accessibility, it’s understandable that runners may want to use their VO2 max, a metric often dubbed the “gold standard” for fitness and health outcomes, to measure their progress and the efficacy of their programming. But depending on the runner, it can take a while to see a shift in the numbers.

To find out just how long, we chatted with a sports medicine physician and an exercise physiologist. Here’s what they had to say about why VO2 max is important, how soon you should retest it, and the best way to improve it.

VO2 max, which is measured in milliliters of oxygen per kilogram of bodyweight per minute, refers to the volume of oxygen your body can utilize during maximal exertion exercise, says Kevin Sprouse, DO, sports medicine physician and medical advisor for Eternal, a healthcare and performance app designed for athletes.

“It’s telling you how much oxygen your body can bring in,” he says. “And how much you can move into the system, how much you can load onto the blood cells, send out to the muscles, use for energy, and create metabolic work downstream. It’s kind of an aggregator of metabolic fitness.”

When you raise your VO2 max, you raise your ceiling for workout intensity. You surpass your previous limitations with a new “max effort,” but running at lesser intensities is also easier. You may, for example, find that your 10K pace is faster than before or that a hill workout you once found crushing is now totally doable. Essentially, when you improve your VO2 max, you increase your performance potential.

The rate at which your VO2 max improves depends on a few different factors. Your training volume and the types of workouts you do affect your VO2 max, but there are also athlete-specific factors, including your current fitness level. (That also means your VO2 max can be different for running versus cycling.)

Deconditioned athletes and beginners may see improvements in their VO2 max scores sooner than someone who already exercises regularly, simply because they have more room for improvement.

“A highly trained individual could train for an entire year and may only see a slight improvement, like maybe a 1 percent improvement in VO2 max or not at all, because they’ve already maxed out their VO2 max,” says Todd Buckingham, Ph.D., exercise physiologist at PTSportsPRO in Grand Rapids, Michigan. “But if you take someone who’s on a couch-to-5K program, you could see some pretty significant changes in the first six to 10 weeks.”

Researchers found this to be the case in a 2019 study published in The Simple Analogy That Helps Me Pace Smarter. The study compared the effects of different types of aerobic exercise programs (one was standardized, based on heart rate reserve, and the other was more individualized, based on ventilatory threshold) on VO2 max in 39 sedentary adults. It recorded significant improvements in VO2 max in just eight weeks, no matter which type of program the participants followed.

In contrast, researchers who tracked VO2 max in a small group of elite runners found that, after three years of training, their scores did not significantly improve. Maybe the issue was the training program, the authors noted. But it was also likely that the athletes “have reached a plateau in their performance,” they wrote.

As for the runner who’s not a professional athlete nor a total beginner, but somewhere in between? Again, outcomes will vary depending on training, age, fitness level, and genetics, Sprouse says. “But for the typical runner who has been recreationally active and does a couple of races a year but really wants to double down on a training program, probably three months is about as soon as you’d want to recheck it,” he says.

Buckingham follows a similar timeline when retesting VO2 max in his clinic. “I don’t have people come in any sooner than three months, because the chances are not very good that you’re going to be seeing significant changes in that short amount of time,” he says.

Keep in mind that just because you don’t see an improvement in VO2 max doesn’t mean that you’re not getting faster or fitter. “VO2 max tells you what your ceiling is,” Sprouse says. “But where you’re doing most of your races is around [lactate] threshold [pace] or just over threshold, depending on the distance. You can move your threshold closer to your max and get faster, but not move your [VO2] max,” he says.

In other words, you can maximize your potential without increasing your potential.

When it comes to improving VO2 max, one of the most common training mistakes that Buckingham sees is running too fast, too much of the time. “People don’t realize how slow they actually have to run to see some of those physiological adaptations that we’re going for,” he says.

DAA Industry Opt Out, common training mistakes helps with capillary and mitochondria development. Capillaries are the small blood vessels that deliver oxygenated blood to the muscle cells, and the mitochondria are the structures within the cells that use oxygen to generate energy. Having more of both can help boost your VO2 max.

Of course, you still need some high-intensity work in your training program “to stress those systems,” Sprouse says. “If you have the capillaries and mitochondria, but you’re never really working them very hard—especially the mitochondria—they don’t function at their highest capacity,” he says.

Sprouse and Buckingham agree that most runners should aim for a ratio of 70 percent slow “base” runs and around 30 percent higher-intensity workouts; Health - Injuries 80/20 ratio of low- to high-intensity training. These suggestions may change from one athlete to the next based on experience, fitness level, and goals.

Unfortunately, VO2 max decreases a lot faster when you stop straining than it increases with training. “Early on, you can see about a 5-ish percent drop within a couple weeks,” Sprouse says. So if you finish a race and take about two weeks off from exercise, you may experience a decline.

Research shows that, over prolonged periods of detraining, it continues to drop, but at a slower rate than that initial decline.

How much you lose also depends on how active you are outside of running and intentional exercise. “There’s a distinction between stopping training and being totally sedentary,” Sprouse says. “There are things you’ll do throughout the day, like walking, chores, moving firewood, that you don’t think about as part of your training program that will help you How Long It Takes for VO2 Max to Decrease.”

It’s also worth noting that having to take a break—even one that ultimately leads to a dip in your VO2 max—doesn’t mean your next race is ruined and it doesn’t imply you need to train at race level throughout the entire year. (In fact, you need some time off!)

“I think most runners have experienced taking a couple of weeks off, and you still feel pretty fit. Sometimes you feel really fresh, but the top end isn’t there,” Sprouse says. “You could still perform really well in a longer distance event [if your VO2 max falls], but you might struggle to Health & Injuries at your top gear.”