VO2 Max

the faster you go the more you use. Its not linear

Your watch has no way to actually calculate your vo2max. It probably just predicts it based on faulty logic. It's a junk function in a world obsessed with data.

Alan

Oh my, I am so confused...

Let's for the sake of simplicity assume all runs are done on flat ground under same environmental conditions.

As pace increases VO2 will increase although VO2 will plateau or top out at some intensity. (That would be VO2max; you do not achieve VO2max on an easy run.)

Heart rate under moderate conditions is going to increase pretty close to linearly with VO2 (and thus with pace). HR will also tend to plateau at near maximal pace/intensity.

Under some conditions your HR even at the same pace/intensity will rise over time (cardiac drift), but so will VO2.

Heart rate though in real life is tricky. It is not the best metric for intensity as a lot of things can affect it: sleep or lack of, temperature, stressors, caffeine, dehydration, etc.

The watches are estimated oxygen consumption probably from speed and HR data. The issue is that since the algorithms used are proprietary it is difficult to assess how reliable or valid they are. Some researchers may have tested them against metabolic carts, but I have not looked for those studies in several years. There are some that have looked at the validity of things like Fitbits. A google scholar search should turn those up.

spokeaboutballs. wrote:

the faster you go the more you use. Its not linear

It's called VO2Max because it's the max volume of O2 the body can use. You don't use more or less VO2Max, or any at all for that matter. It's not a resource itself, but rather a representation of a resource (O2). It's a fixed number at any given time.

Thank you, very helpful post!

Is it possible your watch is estimating the % of your VO2 max that you are using during the run?

I'm curious what watch the original poster is using that gives some VO2 max estimate based on each run.

I had a Polar HRM that calculated an "Own Index" that was supposed to be highly correlated with VO2max, but it was based on monitoring heartrate at complete rest. My understanding is that it was looking at small pulse rate variations while at rest as per some study that looked at this. Anecdotally it gave me very similar numbers to my Daniels vVO2max at the time. I've never had a formal VO2max test, nor do I see much point in it from a training perspective.

There are Garmins which give a Vo2max estimate. Not very useful. A Vo2 estimate would be much more beneficial.

HR itself is a pretty good self-regulatory mechanism. Back in the day I was pretty skilled at taking HR mid-run. Two fingers to the neck, count for 6, x10. Close enough estimate for me. Worked wonders on tempos and such. Didn't need a garmin or measured miles, just say "hey lets hammer these last few miles", after about 1/2mi check HR and maintain.

Alan

OP what you see is the peak o2 uptake during your workout. To get your individual vo2max do a warmup 30 min and then do an all out 1000

Althought vo2 max doesn't tell to much. Friend has 72 me 68 and i will beat.his ass

Not sure what watch you're using. My garmin has a "VO2 Max" function that I have a hard time believing and do not rely on, but there is minimal fluctuation, +/- 1-2 points depending on the run. Most days it does not change even if day one is a workout and the next day is easy I will get the same reading.

The watch also has a race predictor with times I know for a fact I am not capable of running at the moment.

The race predictor function is hilarious. It told me I was capable of a 2:15 marathon. I think realistic would be 2:40, if I doubled my weekly mileage. And then only maybe. I pity anyone who tries to train with the advice that thing dispenses.

garmin race predictor wrote:

The race predictor function is hilarious. It told me I was capable of a 2:15 marathon. I think realistic would be 2:40, if I doubled my weekly mileage. And then only maybe. I pity anyone who tries to train with the advice that thing dispenses.

I use this function to post equivalent times of my runs on facebook.