How VO2 Max is calculated?

Does the length of the run have an impact on the measurement? It seems like pace is a large piece of the equation. My pace is much quicker over 2 miles than it would be for a 6 mile run. I'm wondering if the measuring takes place during the first 'x' amount of time during a run or if the whole run's pace is used.

thats what i was asking in my first post. i read the whole document and could not still answer to which part of lets say 1 hour walking is counted.

in my case just improving the pace could not help

I have been running for over 40years(over 88,000 miles) and for the first 20 years or so never had a clue what my VO 2 Max was as well as cadence, vertical whatever, etc and I found by running and varying pace and distance mixed in with rest days my running improved(at least over the first 10 years) without knowing any of the data. I did jump on the Heart Rate wagon when Polar started selling HR straps/watches.
My suggestion, get out- run,cycle walk. Be consistent and there will be improvement. Oh, my VO 2 Max- per my Garmin ranges around 42-44. Not too shabby for a soon to be 75 year old who has been very fortunate and still runs 40-50 miles a week.
My thought, TMI may get in the way of the simple act of running. Nick

The VO2 Max scale makes absolutely no sense!!! I'm a 52 year old male. According to Firstbeat's white paper (graph 3A) and Garmin's 935 manual (page 33) my score of 40 rates me as "good". Both my VA3 and 935 show the score of 40, but it's rated as "fair" and it's just 1 digit shy of a "poor" zone rating. When you look at the score of 40 under "fair" it put's me in an age group 20 years my junior. Garmin Connect, GCM and my watch all have my correct age and gender. What the watches are showing me and what Firstbeat and Garmin publish are completely different. It makes no sense at all.

very nice details you added both of you, but we speak with the time now as we have the watches we are looking to see whats wrong

i like to see my statistics correct thats the reason i paid for the watch otherwise we go back to 80s when we run without a clue.

Does the length of the run have an impact on the measurement? It seems like pace is a large piece of the equation. My pace is much quicker over 2 miles than it would be for a 6 mile run. I'm wondering if the measuring takes place during the first 'x' amount of time during a run or if the whole run's pace is used.

If you take a look at the Firstbeat white paper that's linked above what you'll see is that all data that is considered "good" by the algorithm is used for the Vo2Max estimation. So they're not taking a single 10-15 minute sample and evaluating that, but rather all of the good samples within a run and looking at those. (See Fig 1 in the white paper for what is considered good)

The way I read that it would seem that a longer run in and of itself doesn't have an impact but it will have a higher probability of producing more good data so can beneficial. There's probably a point of diminishing returns because I think I saw a bit in there about cardiac drift which might be filtered out as "not good" data so a run long enough for drift to set in won't see that later HR data being used in the calculation.

Of course this is just in reference to how Vo2Max is calculated for a particular run. Long runs are very important to overall training and doing them regularly will improve fitness which will in turn improve your Vo2Max score.

Always keep in mind that a) Vo2Max here is just an estimate; b) It's not meant to be a score that you target for improvement on it's own; c) It's not a value that goes up indefinitely. Eventually it will plateau with small 1-2 point variations unless you really ramp up training or get sick/injured.

If you follow good training principles, exercise regularly, and stay healthy the number will go up until it hits that plateau. From there you can use it to gauge whether you're gaining, losing, or maintaining fitness.

The VO2 max on the VA3 is lower than what my Forerunner 630 calculated. Right out of the box, both showed near the same numbers for about a month. Then out of no where, I dropped almost 10 points even though I was peaking in my training cycle (60 mile+ weeks).

The auto calculated heart rate zones appears to be the culprit because when the VO2max dropped I noticed that my heart rate ranges had changed making it so that I was always in Zone 5 (red) even though I was not taxed. Recently the HR Zones have adjusted again and most of my runs have returned to Zone 4 (orange). Voila!!! My VO2max has gone up 6 points without any specific conditioning (e.g., speedwork etc).

Moral of the story, check your heart rate zones - you may need to manually adjust.

My HRMax got reset to the 220-age formula instead of my known, and much higher, number with the last FW update on my 735. I went a couple of days not being aware of it so had several runs that should've been TE 3.2-3.6 show as TE 5 and my Vo2Max dropped 4 points.

Random setting changes is one of the things where Garmin really trips users up with updates.

so to set it manually i guess you have to test your limits? by that i mean to run as high as you can and find your MaxHR so you can set it?

is that a more accurate method for the zones?

There's a couple of different methods knocking around the internet for determining your maximum heart rate. The keys to any of them are to be healthy and rested going into it and be prepared to truly push yourself to the point of coming close losing your last meal. ;)

A popular one that I use is to find a hill that's a couple of hundred yards/meters long and around a 3-5% grade and then.
1. Warm up with easy running for 10-15 minutes
2. Run up the hill at 90% effort and jog back down 3 times
3. Run up the hill at maximum effort at least once

When you look at the data after the run the highest HR number you see, that isn't a random spike of some sort, is a good number to work with. It might be higher or lower than the formulas give but it will be specific to your physiology instead of something that's pulled from an actuarial table.

Other people will use their HR at the end of an all-out 5k race, some will add 5bpm to their 5k HR, some do something different. No matter how you determine it as long as you feel that there's no way you could've pushed yourself any harder then it's probably a better number "for you" than any formula will be.

Spot on R Tellis. It is a shame that there is so much misunderstanding about Max HR. That damn 220- age fits about 25-30% of people.I feel bad for folks that use that and get worried when their HR goes above that number.
I sent a PM to Herman at First Beat questioning why there is not data presented for us runners over 65. I am hoping when they extend it I will be in Super Star status. It appears it drops by 3 every 5 years. If that is the case. My 40-44 VO2 max readings over the last few years will put me near the top at age 75(:.
I appreciate your posts. Well thought out. Nick