How Does Garmin Calculate VO2 Max? – UPDATED 2021 – How Accurate Is It?
You may have heard your fellow cyclist’s or runner talk about their VO2 max during a coffee stop. Checking their Garmin to see their latest training improvements. As you know most Garmin watches provide an estimated VO2 max number based on your current fitness, But how does Garmin calculate VO2 max? In this article we find out how.
How Does Garmin Calculate V02 Max?
Whether your a competitive athlete or enthusiast, most likely you have heard of VO2 max. VO2 max attributes to the highest volume of oxygen you can employ during exercise. It’s generally used to test the aerobic endurance or the cardiovascular shape of athletes during a training period.
Not many people can afford the luxury of being lab-tested thought. That is why brands like Garmin have developed a way to estimate or calculate VO2 max through their wearables.
Garmin uses their Firstbeat Fitness Test to calculate VO2 Max for a variety of activities. You can see their patent on the technology here.
For Garmin to calculate the athletes VO2 Max it collects the following data from each user:
1 – Age and personal background is recorded
2 – Exercise is started with data collected from heart rate and speed.
3 – The data collected from the activity is segmented into different heart rate scales based on the user’s background information.
4 – During the activity reliability is measured based on continuous activity (stopping etc)
5 – The most credible data segments are then used to estimate the aerobic fitness level through heart rate and speed data.
Vo2 max Garmin calculation
Speed data is then taken from reliable segments and used to estimate a VO2 Max score. This is taken from 20-30 second periods using one of the VO2 calculations below:
Walking and Pole Walking: Theoretical VO2 (ml/kg/min)=1.78*speed*16.67[tan(inclination)+0.073]
Running on a Level Ground: Theoretical VO2 (ml/kg/min)=3.5 speed
Running in a Hilly Terrain: Theoretical VO2 (ml/kg/min)=3.33*speed+15*tan(inclination)*speed+3.5
Cycling: Theoretical VO2 (ml/kg/min)=(12.35*Power+300)/person’s weight
Rowing (Indoor): Theoretical VO2 (ml/kg/min)=(14.72*Power+250.39)/person’s weight
Unit of speed = kilometers per hour (km/h)
Unit of inclination = degrees)(°)
Unit of power = watts (W)
Unit of weight = kilograms (kg)
From these calculated values heart rate is then used to define the effort of segments. So after you have set your heart rate training zones, Garmin uses it to determine the effort you are working at. That effort is then used to determine VO2 as a %VO2max value.
How Accurate is Garmin’s V02 Max?
Measuring data through wearables is one of sport’s greatest breakthroughs which helps us to analyze our training better than ever. But how accurate is Garmin’s VO2 max? And how does it pair against laboratory testing?
Firstbeat Analytics (a unit of Garmin Ltd) carried out its own research to verify its technology and it’s effectiveness at determining VO2max. The study used 2690 runs from 79 different runners that had previously had their VO2 max tested 4 times during a 6-9 month period. The results from these runners found that Garmin’s VO2 max estimation was 95% correct and the error was less than 3.5ml/kg/min.
The results are reasonably accurate granting most sub maximal testing has an error of 10-15%.
While this all sounds too good to be true there are some other factors that come into play. If a user has underestimated their HRmax by 15 beats/min the VO2 max will show an error of around 9%. If on the other hand, they overestimate 15 beats/min they will see a discrepancy of about 7%.
Although this might sound like a lot, if the athlete’s real HRmax is known, the level of error falls to that of 5%.
So the bottom line is keep the tracking of your workout and user information accurate. That will then make Firstbeat’s fitness test technology a good tool for estimating Vo2 max.
References: Retrieved from https://sites.udel.edu/coe-engex/2019/03/16/how-accurate-is-your-garmins-vo2max-estimate/
Which Garmin Watches Measure Vo2 Max?
There are multiple watches on the market that measure VO2 max, but which of the Garmin watches measure Vo2 Max? Below are a few of the models that use the Firstbeat Technology.
Vivoactive comes with preloaded apps like yoga, cycling, and swimming. It can approximate your fitness levels through VO2 max and help you track stress levels too.
The Forerunner 45 is known for its accuracy. It comes packed with numerous features such as VO2 max tracking and offers up to 7 days of battery life.
Garmin Fēnix 6S
The Fēnix 6S includes running dynamics and advanced training metrics for the runner. It also tracks your hydration and recovery time while providing daily workout suggestions.