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VO2 max gets a lot of attention in the fitness world—which is probably why you see it tracked on your smartwatch or cycling computer. But what is VO2 max exactly? And why is it important for cyclists to get familiar with this metric?
Also referred to as maximal oxygen uptake, measuring your VO2max can give you an inside look into your current fitness levels, helping you gauge the effectiveness of your training program and make tweaks if necessary. It also helps you see how you your fitness is improving, plus how you stack up to other cyclists.
To put the measurement into practice, here’s what to know about VO2 max, including how to see your stat improve.
What is VO2 max, exactly?
VO2 max is a measurement of the maximum (max) volume (V) of oxygen (O2) your body can take in and use exercise. It’s measured in milliliters of oxygen consumed in a minute per kilogram of body weight (mL/kg/min).
The higher your VO2 max, the more efficiently your muscles utilize oxygen and convert it to energy, which means it makes exercise feel easier at specific intensities. Oxygen is used to create adenosine triphosphate (ATP), the energy currency that powers your every movement. The more oxygen you’re able to use for ATP production, the more energy you’ll have for cycling.
“It might help to think of your VO2 max like a car’s engine, but for your body,” says Todd Buckingham, Ph.D., visiting professor of exercise science at Grand Valley State University. “The bigger your engine, the greater your capacity for being a good endurance athlete.”
Keep in mind, though, that just because you have a high VO2 max doesn’t mean you’ll automatically be the fastest cyclist. There are other factors that go into performance, such as fueling properly, training different energy systems, and how intensely you can exercise before lactate (a byproduct of exercise) builds up in the blood (also known as lactate threshold), says Garret Seacat, C.S.C.S., a cycling coach and the owner of Absolute Endurance.
That said, “having a higher VO2max will increase the likelihood of performing better in your race,” Dr. Buckingham says.
As an added bonus, research suggests that higher VO2 max levels are associated with greater longevity, so it’s not just your performance that gets better with a higher VO2 max.
How do you measure VO2 max?
To get the most accurate measurement of your VO2 max, you have to swing by a physician’s exercise lab or sports science lab that offers VO2 max testing.
A VO2 max test is considered the gold-standard measurement of endurance, notes Johns Hopkins Medicine. The test typically lasts only eight to 15 minutes and involves walking, running, or cycling while breathing into a mouthpiece that collects your exhaled air and sends it into a machine (also known as a “metabolic cart”) through connected tubes.
You’ll start off by pedaling at a low power output and a skilled technician will increase the power gradually until you burn out. But rest assured that only the last few minutes of the test are really tough, Buckingham says.
The machine is hard at work, too. While you exercise, it analyzes and records how much oxygen you’re using. Using this information, the technician will be able to calculate your VO2 max.
While the VO2 max test can be done on a treadmill or bike, you’ll get the most accurate measurement on a bike. “Getting a cyclist to do a running-based test may underestimate their VO2 max, as they are engaging muscles they may not be used to using,” says Avi Silverberg, M.S., C.S.C.S., a strength and conditioning coach who works with competitive indoor and outdoor cyclists. Many labs even allow cyclists to bring in their bike and set it up on an indoor bike trainer.
For cyclists who can’t get to a lab, there are more accessible ways to estimate VO2 max. However, none will be as accurate as a lab test. So, take any estimates from alternative methods with a grain of salt.
The easiest method for estimating VO2 max is to let your watch or fitness tracker do it for you. Some models use heart rate data and exercise data (like pace) to calculate your VO2 max. However, research published in Cardiovascular Diagnosis & Therapy in 2019 shows that wrist-worn devices become less accurate at measuring heart rate when runners pick up their pace. Having darker skin also throws off accuracy. Less accurate heart rate measurements may mean less accurate VO2 max estimates.
There’s no perfect VO2 max number. However, you can compare your number to averages to get an idea of how you’re doing. Active men between the ages of 18 and 45 typically score between 45.5 to 46.4 mL/kg/min, whereas very active men may reach as high as 85 mL/kg/min, according to the Cleveland Clinic. Active women within the same age group usually fall between 33 and 36.9 mL/kg/min, with very active women potentially reaching 77 mL/kg/min.
Why should cyclists know their VO2 max?
Measuring your VO2 max can give you an idea of how you compare to other cyclists. You can compare your numbers to cyclists who share characteristics like age, gender, and experience level. But you can also use the measurement as a way to see your own progress over time.
Keeping tabs on your VO2 max can help you gauge how your fitness is (or is not) improving with training. Again, the higher your VO2 max, the easier it will feel to perform exercise at a specific intensity, so you’ll be able to crush harder workouts without feeling like you’re working harder—a major pro of training to improve this measurement.
According to Buckingham, many pro athletes track progress by getting their VO2 max tested at the beginning of every training block—that’s six or more times per season. For non-professionals, two tests per year is sufficient. “Start with one at the beginning of your season and reassess halfway through to make sure your training is having the desired effect,” Buckingham says.
If your VO2 max isn’t improving the way you’d hoped, it may be time to tweak your program (and maybe time to hire a coach).
How can you improve your VO2 max?
UC Davis Health notes that there are many factors that can affect VO2 max, including age, body composition, gender, genetics, and—of course—training. While you can’t control your genetics or age, you can manipulate your workouts to elevate your VO2 max.
Cycling at lower intensities (between 50 to 70 percent of your maximum heart rate) is essential. “Training at low intensities helps increase the number of mitochondria and capillaries in our muscles,” Buckingham says.
Mitochondria are the cell structures where oxygen is used to create energy for the working muscles, while capillaries are the tiny blood vessels that enable the exchange of carbon dioxide and oxygen. More mitochondria means more sites where oxygen can transform into energy. Similarly, having more capillaries means getting more oxygen to the mitochondria and more carbon dioxide out of the muscles.
However, some studies suggest that high-intensity training (between 80 to 100 percent of your maximum heart rate) provide the best method to improving your VO2 max. Some science also suggests you can train at higher intensities in lower doses to achieve improvements in VO2 max, making it an efficient way to improve fitness.
Workouts done at a higher intensity also boost mitochondria. “This is why it’s important to vary your training and not just train at the same intensity for every workout,” Buckingham says. He recommends doing the bulk (roughly 80 percent) of your cycling workouts at a lower intensity and a portion (about 20 percent) at a higher intensity.
Try this high-intensity cycling workout for improving VO2 max, courtesy of Seacat. After warming up for 10 minutes at a low intensity:
- Cycle for 2 minutes at an all-out effort you can sustain for the entire interval
- Pedal for 2 minutes at an easy recovery pace
- Repeat until you’ve completed four rounds total
- Recover for 5 to 10 minutes
- Complete another four rounds of 2 minutes on, 2 minutes off
Seacat recommends doing this workout on the road with a steady uphill or into a headwind. However, it can also be done indoors if needed. Aim for a pedal cadence between 75 and 90 revolutions per minute.
Keep in mind, improvements in VO2 max won’t happen over night—it takes time to see this number change. So stick with your workouts and keep it consistent, and that’s when you’ll see results.
Lauren Bedosky is a freelance health and fitness writer who specializes in covering running and strength training topics. She writes for a variety of national publications, including Runner’s World, Prevention, Experience Life and Women’s Running.
Tamanna K. Singh, M.D., is a board-certified adult clinical and sports cardiologist and RRCA-certified run coach. She earned her medical degree from Boston University School of Medicine and completed her Internal Medicine Residency at Boston Medical Center. She completed her Cardiovascular Medicine fellowship at the Icahn School of Medicine at Mount Sinai, New York, New York and her specialty training in Sports Cardiology at Massachusetts General Hospital. She is currently the codirector of the Sports Cardiology Center at Cleveland Clinic in Cleveland, Ohio and assistant professor of medicine at the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University. To date, she has held several council roles with the American College of Cardiology (ACC). As a sports cardiologist, Dr. Singh provides cardiovascular care for professional, competitive, and recreational athletes and describes herself as an advocate for safe participation in sports. Media and print contributions include the New York Times, Wall Street Journal, Time Magazine, and others. Outside of her profession, she enjoys running marathons, hitting the weights in the gym, playing sous-chef to her wonderful husband while cooking plant-based meals, and playing with her four beautiful dogs.
