How Does Garmin Calculate VO2 Max – The Science Behind It

Whether you’re into your trail running, cycling, or just aiming to improve your general fitness, you've probably come across VO2 max on your Garmin device. It’s one of those key metrics that help us track our fitness level over time, but do you know what it actually means or how Garmin works it out?

In this blog, FitstrapsUK (The number one place online for Garmin Watch Straps) is going to dig into this VO2 max – what it is, how Garmin calculates it, what’s considered a good score, and how you can improve it. Let’s also clear up the debate about how accurate this number really is. By the end, you’ll have a clear understanding of how VO2 max helps you get fitter and faster than ever before.

So What Is VO2 Max?

VO2 max stands for the "maximum volume" of oxygen your body can use during exercise. It's a measure of your aerobic fitness and reflects how well your heart, lungs, and circulatory system deliver oxygen to your muscles. The more oxygen you can use, the better your aerobic energy production will be.

Think of it as your bodies engine of your fitness levels. The bigger the engine, the faster and longer you can go without getting tired. VO2 max is generally expressed in millilitres of oxygen used per minute per kilogram of body weight (ml/kg/min). The higher the number is, the better you are when it comes to cardio.

When you exercise, your body needs oxygen to fuel aerobic metabolic pathways in your muscles. The more intense the exercise, the more oxygen your body demands. At a certain point, your body hits its maximum rate of oxygen consumption, and that’s your VO2 max. So, in short, VO2 max is a measure of how much oxygen your body can use at peak performance.

How Does Garmin Work Out Your VO2 Max?

Garmin devices use a combination of pace and heart rate, plus some very clever algorithms, to estimate your VO2 max. But to get the most accurate reading, you need to be running or cycling at a steady pace, and the data must be recorded outdoors.

The device uses your heart rate and speed data to figure out how efficiently your body is using oxygen during exercise. It does this by analysing your heart rate zones, along with the GPS signal from your run. The relationship between your heart rate and the intensity of the exercise gives a pretty solid estimate of your VO2 max.

It’s not just your heart rate Garmin’s looking at. It also considers how much oxygen you’re using and how fast you’re going. If you’re keeping up a good pace at a relatively low heart rate, Garmin will score your VO2 max higher because it means your body is efficient at getting oxygen to your muscles.

That said, it’s important to note that Garmin’s VO2 max readings are only estimates and not fully accurate. While Garmin devices use extremely advanced algorithms, they’re not as precise as lab tests. But for the average user, they’re accurate enough to give a good idea of your aerobic fitness over time.

What Is a Good VO2 Max Score on Garmin?

Now that you know how Garmin calculates it, the next question is: what's a good VO2 max score?

A "good" VO2 max depends on your age, gender, and fitness background. For example, a VO2 max score of 40-50 ml/kg/min is generally considered good for a healthy male in his 20s to 30s. For women in the same age group, a score of around 35-45 ml/kg/min is considered good. As we age, our VO2 max naturally declines, so don’t be too hard on yourself if your number isn’t as high as you’d like. It’s all relative to your fitness level and age group.

For runners, particularly trail running enthusiasts, VO2 max is a great indicator of how efficient you are at using oxygen over tough terrain. In fact, elite endurance athletes can have VO2 max scores of over 70 ml/kg/min! But you don’t need to always aim for elite-level numbers. What matters is improving your personal score over time.

If your Garmin device shows a lower VO2 max than expected, don’t panic. It’s just one measure of fitness. What’s more important is to track trends. If your score is improving over time, you’re on the right track.

The Benefits of Fitstraps for Your Garmin Watch

Keeping your Garmin watch in top form is crucial if you’re serious about tracking your fitness data. That's where FitstrapsUK comes in. At Fitstraps, we make sure that Garmin watch lovers from all sporting backgrounds have access to stylish, durable replacement straps.

Whether you’re looking for a new strap to match your outfit or need a refresh for your current one, Fitstraps has you covered. With multiple styles and colours available for every Garmin model, from Forerunner 35 wrist straps right through to the Fenix 7 bands your watch can look as good as the data it tracks. So, don’t settle for a worn-out strap – upgrade your look and keep your Garmin device performing at its best with Fitstraps.

How Do I Improve My Garmin VO2 Max Score?

Improving your VO2 max score takes time and consistent effort, but it’s totally achievable. Here’s how you can give it a boost:

1. Do High-Intensity Interval Training (HIIT): HIIT workouts are great for improving your VO2 max because they push your body to work at its maximum capacity, helping increase your oxygen consumption.
2. Increase Your Aerobic Base: Long, slow runs or rides at a moderate pace help build endurance. Over time, this strengthens your heart and improves the efficiency of your aerobic metabolic pathways, boosting your VO2 max.
3. Track Your Heart Rate Zones: Use your Garmin device to monitor your heart rate zones during workouts. Staying within the optimal zone for aerobic training can help improve your VO2 max.
4. Strength Training: Building strength, especially in your legs, helps improve overall fitness and the ability to sustain longer workouts. This enhances your body’s ability to use oxygen efficiently.
5. Consistency: Like anything in fitness, improving your VO2 max takes time. Stick with a structured training plan, and your aerobic fitness will improve.

The key is to train smarter, not harder. Gradually increasing the intensity of your workouts will lead to steady improvements in your maximum rate of oxygen consumption. For assistance in structuring your performance Garmin Coach can be a great help to many athletes looking to improve their performance. 

Is VO2 Max on Garmin Accurate?

Garmin devices are pretty good at estimating VO2 max, but let’s be clear – they’re not perfect. The VO2 max feature on your Garmin watch is based on formulas and assumptions that may not be as precise as lab-based tests.

In a lab setting, VO2 max is measured by having you run or cycle while breathing into a mask that monitors your oxygen intake and carbon dioxide output. This is obviously way more accurate because it’s directly measuring the gas exchange in your body.

Your Garmin is looking at things like pace and heart rate, but it’s still making an educated guess based on your speed data and how your circulatory system handles exercise. For most of us, though, Garmin’s VO2 max estimates are close enough to give us a good sense of our fitness level and track our progress.

If you're after pinpoint accuracy, a lab test is the way to go. But if you’re using your Garmin device as part of your regular training, its VO2 max estimate is a great way to gauge where you’re at and where you’re heading.

Why Is My VO2 Max So Low Even Though I Exercise?

If your VO2 max is lower than you’d expect despite regular exercise, don’t worry – you’re not the only Garmin Watch Warrior to have said this. There are a few reasons why this could be happening, and it's not necessarily a reflection of your true fitness level.

First off, as we mentioned above your Garmin's VO2 max score is an estimate. If you’re not consistently training with the right intensity or your heart rate zones aren’t dialled in correctly, your VO2 max readings might be off. Remember, Garmin uses your heart rate and pace to estimate how well your body uses oxygen, so if your pace is too slow during a test, or your heart rate is too high for the effort, it can skew the results.

Another reason could be that you’re focusing on the wrong types of workouts. If you’re doing mostly strength training or lower-intensity exercises, like walking, your aerobic fitness might not improve as much as you’d like.

VO2 max is all about how efficiently your body uses oxygen, so you need to include activities that challenge your aerobic metabolic pathways, like running or cycling, at moderate to high intensities.

Finally, lifestyle factors like poor sleep, stress, and dehydration can also affect your VO2 max. So, if your score’s not where you want it to be, look at the bigger picture – it could be down to more than just your workouts.

How Often Does Garmin Calculate VO2 Max?

Garmin typically calculates your VO2 max after every outdoor run or ride, as long as you’ve met the right conditions. The key here is that the activity has to be long enough, intense enough, and recorded outdoors using GPS.

Your Garmin device needs a consistent GPS signal, along with data from your heart rate, pace, and speed to give you an accurate estimate. So, if you're just going for a short, easy jog or ride, you might not see an update to your VO2 max.

For runners, Garmin tends to update your VO2 max after any workout lasting at least 10 minutes where you’re maintaining a consistent pace. Cyclists need to go for a bit longer to get a reliable calculation, but again, the same rules apply: stay steady and keep the heart rate up.

Garmin doesn’t calculate your VO2 max during every single workout, though. If your session is too short, or you’re not pushing yourself enough, the device won’t bother updating it. So, if you're looking to track changes in your VO2 max regularly, aim for moderate-to-intense sessions that last long enough for Garmin to collect the necessary data.

Conclusion

VO2 max is one of the best indicators of your aerobic fitness and overall performance capacity. Garmin devices offer a convenient way to estimate it, using a mix of GPS signals, pace, and heart rate data to help you track improvements over time. Whether your goal is to improve your VO2 max score, run faster, or just get fitter, your Garmin is a fantastic tool for measuring progress. And if you want your Garmin watch to look as good as it works, don't forget to check out Fitstraps for a stylish upgrade!