VO2 max measures your physical condition
VO2 max. it tells you how well your body uses oxygen during exercise. It is a measure of aerobic fitness and endurance capacity. The higher VO2 max you have, the better. For reference only, most Tour de France the cyclists have a VO2 max greater than 70 ml/min/kg and the winners of the general classification have more than 80 ml/min/kg. Untrained people would measure between 25 and 35 ml/min/kg, but experienced amateur cyclists could push their VO2 max to 50. If you want to know what a good VO2 max is for your age and gender, you can see the Garmin spreadsheet here.
How does Garmin measure your VO2 max?
Garmin devices allow you to measure your VO2 max frequently and at no additional cost. Garmin partner Firstbeat Analytics developed a method to estimate VO2 max. only with the data of his watch. Your Garmin combines various statistics that it measures directly or asks you to input.
- Rhythm and heart rate during exercise.
- Resting heart rate
- heart rate variability
- Years
- Gender
- Weight
Scientists test the accuracy of the Garmin device
With every new smartwatch feature, it’s natural to wonder how accurate and reliable it is. Researchers at the University of Würzburg, Germany I decided to answer that question putting the Garmin Forerunner 245 to the test against benchmark lab equipment. They recruited 23 runners (11 men, 12 women) and determined their VO2 max in the laboratory during a treadmill ramp test. They compared this information to three outdoor runs, where the Garmin watch recorded VO2 max.
Garmin had a 5.7% discount
The study found Overall, the Garmin Forerunner 245 had an error of 5.7% compared to laboratory measurements. The clock was most accurate in runners who had a VO2 max in the range of 44 to 55 ml/min/kg, with an error of only 4.1%. For corridors below or above these values, the discrepancy was greater. The study shows that the Garmin watch is accurate enough to track changes in VO2 max. But it may not be accurate enough to prescribe exercise intensity based on VO2 max measurement.
The results of this new study are very similar to previous research. A study looking at the Garmin Forerunner 920XZ showed a 7.3% discrepancy from lab tests. another studio who used the Garmin Fenix 6S watch also found similar numbers. Firstbeat Analytics did their own study and found an error of 5%, which equated to 3.5 ml/min/kg.
Be sure to enter accurate HRMax
The only thing we know from these studies is that accuracy is highly dependent on how accurately a person sets their HRMax maximum heart rate value on the watch. The underestimation of 15 bpm results in the VO2max the error reaches 9%, and the overestimation by 15 bpm leads to an error of 7%. So if you want to get VO2 max measurement. more accurate from your Garmin, be sure to perform an accurate maximum heart rate test and use that value to define your heart rate zones in Garmin settings.
