How accurate is the Vo2Max value ? It may have been discussed already. I just want to know that when my Vo2Max improves, it is true. I do not have access to equipment to test its accuracy but I just wonder. Thanks
Like anything, it's accurate as the information you feed it. Makes sure you supply good heart rate data, a chest strap is usually the most reliable. Look for trends over periods of 4 plus weeks, rather than tracking daily fluctuations. There's heaps of posts about this. Well worth searching through the forums and reading some of them.
It is a calculated value and depends heavily on your input, so be sure to have your parameters set correctly. E.g. the max heart rate has to be sport specific, meaning that you enter the maximum value you have seen recently instead of your physiologically possible value. The prediction tables for VO2max values are more or less based on the assumption that in the OPTIMAL case these could be achieved.
My favorite tool for these kinds of estimations is runalyze. You get Vo2max estimates there and much more. Worth a try, it is free.
It is a calculated value and depends heavily on your input, so be sure to have your parameters set correctly. E.g. the max heart rate has to be sport specific, meaning that you enter the maximum value you have seen recently instead of your physiologically possible value. The prediction tables for VO2max values are more or less based on the assumption that in the OPTIMAL case these could be achieved.
My favorite tool for these kinds of estimations is runalyze. You get Vo2max estimates there and much more. Worth a try, it is free.
I can't tell you how accurate it is, for instance, with respect to a gas exchange test baseline. What I can say from personal experience is that I find it to be very relevant, and a useful training indicator. The value also seems to respond pretty quickly to changes. For example, I basically stopped (triathlon) training entirely after a 70.3 in June, and shortly after beginning to run again (2 runs ish, I think?), my VO2 max dropped from the race-ready value of 54 to 48 now, which seems totally believable relative to my current performance.
But the short version is that they believe the estimate to be accurate to within about 5%. Note that they stress the importance of having an accurate estimate of your maximum HR to get an accurate estimate of VO2Max, and without an accurate HRMax, accuracy of the VO2Max prediction drops to about 9%.
Note also that it works by comparing your HR (as a % of HRMax) with your running pace (or cycling power). So running on a hot day, or when you are fatigued, will lead to a higher HR than the effort level justifies, and the watch will therefore report a lower VO2Max for that day.
mcalista I do not run or a little indoor but found out that walking 10 mn everyday with the chest strap gives me a new Vo2Max value every week as i improve my walk. So i guess a combination of gps and fast paced walk also work. That makes me a happy camper. Thanks for the link. very good paper.
Note also that it works by comparing your HR (as a % of HRMax) with your running pace (or cycling power). So running on a hot day, or when you are fatigued, will lead to a higher HR than the effort level justifies, and the watch will therefore report a lower VO2Max for that day.
Which should, in theory, be automatically recognized as something of an anomaly (the fact that you are suddenly one day struggling compared to normal), and as a result will have a substantially reduced impact on your actual VO2max estimate. This sort of thing is a big part of what is being referenced when you read things like 'the more you use your watch, the better it learns about you."
As noted by someone above, the generally cited number is that VO2max estimated using Firstbeat analytics is accurate with 5% of laboratory tests.
If anyone gets really ambitious, you can dig out a lot of validation and degree of accuracy materials from here.
HermanB I re-visit those white papers from time to time, and always find new information in them. However, take Recovery Time Advisor for instance, and I am disappointed that it's not as compelling as in the Firstbeat's service. With Garmin there are just three different recovery advices, green (train as usual), orange (easy effort recommended), and red (train easy or rest). On Firstbeat you get an actual TE number to aim your next workout for. Now, I know the representations of your algorithms in my 935 are very rudimentary compared to the full-fledged Firstbeat service, and understandably so given the service's price point. But is it possible to roughly map recommended TE to the orange, and red Recovery Time Advisor?
