Run vs Trail Run?

You’re not any ‘less fit’ because you’re VO2max estimate is based off a a combination of trail and road runs. It’s only a number. It does affect bragging rights though.

Trail Run inhibits the calculation of VO2 Max and LTHR.

Since FW 8.0 I noticed running-VO2Max updates (twice) after activities that also (I thought) should not recalculate VO2Max: strength training and walking, resulting in a temporary epic VO2Max number. Great stuff to brag about indeed!, but nobody believed me ("Oh that must be a software glitch..").

You’re not any ‘less fit’ because you’re VO2max estimate is based off a a combination of trail and road runs. It’s only a number. It does affect bragging rights though.

Given VO2Max feeds into so many of the other Firstbeat metrics, a reasonably accurate number is more than just bragging rights.

Given VO2Max feeds into so many of the other Firstbeat metrics, a reasonably accurate number is more than just bragging rights.

Yes. in the winter I regularly run on snow sufaces with a lot of "slip". Although I am working hard, my GPS pace is of course slower than on dry pavement. This caused very low VO2max as well as incorrect Training Status information. I will use Trail Run from now on in those conditions. Thanks for the tip!

Given VO2Max feeds into so many of the other Firstbeat metrics, a reasonably accurate number is more than just bragging rights.

But since VO2max is affected by every activity, then every activity should be included if you use that argument.

Given VO2Max feeds into so many of the other Firstbeat metrics, a reasonably accurate number is more than just bragging rights.

Could you please point or link us to where either Firstbeat or Garmin has stated that any of the other Firstbeat metrics uses the derived value of the VO[SUB]2[/SUB]max estimate as an input variable? Remember, where there are two distinct functions [font="Book Antiqua"]f(x,y)[/font], and [font="Book Antiqua"]g(x,y,z)[/font], the assertion that function [font="Book Antiqua"]f[/font], “feeds into” function [font="Book Antiqua"]g[/font] would not be logically true, unless you can refactor function [font="Book Antiqua"]g[/font] to contain function [font="Book Antiqua"]f[/font] in its formulation.

Firstbeat do not publish their algorithms, but they do publish a number of white papers on their metrics are derived, and the science behind them.

https://assets.firstbeat.com/firstbeat/uploads/2015/11/white_paper_epoc.pdf

Take a look at figure 2 for starters. EPOC is a key component of several other metrics, like Training Load, and Training Effect.

https://assets.firstbeat.com/firstbeat/uploads/2015/10/FFW609US05-171.pdf has numerous references of calculation of Training Effect based on comparison with VO2Max.

https://www.firstbeat.com/en/consumer-feature/real-time-performance/ has a more explicit statement that the Real Time Performance is based on comparisons with your baseline VO2Max.

Garmin provide some more information on the metrics at https://www.garmin.com/en-US/runningscience/
Race Predictor. "Once a VO2 max is established, your device can provide a target race time based on your current state of fitness."
Performance Condition: "is a real-time assessment of the deviation from your baseline VO2 max, with each point on the scale representing about 1% of your VO2 max."
Training Status. "the calculation utilizes several dimensions of a personalized model of your physiology. Changes in your VO2 max fitness level in light of your recent training loads over time indicate the effectiveness of your training."

I recall a post from @hermanB where he describes how TE is calculated using VO2max (can't find the post now). Essentially TE was calculated using activity class (how active you are) - low activity class, TE rises quickly, higher level TE rises slower, more effort required for higher TE levels.

Hence the problem for activities that don't generate a Vo2max, such as trail running profile or anything without GPS, treadmill etc. If the calculated Vo2max for an athlete is not representative of the training performance, TE/training status will be under or overestimated.

For this issue, I hope that FirstBeat can improve the algorithms in the future.

I'm with philipshambrook on this I'd rather have all my run activities input to VO2 max etc. I realise that equivalent pace for the same distance on many off-road runs requires greater effort but about half my running is off road in various forms so I would rather have all the runs input to my stats. The road runs that I do also vary enormously in required effort for the same distance so to take it to extremes I would only measure VO2 on my flat straight road runs that are sheltered from strong headwinds

Firstbeat tell us they have the ability to analyse the run and only use data that they deem 'relevant' in their calculations. Since 'relevant' is subjective, it is possible that 'good' data is dumped and 'bad' data kept.

The VO2max on these devices is an estimate. If you incorporate all your activities you are more likely to get a closer estimate to reality than when you select which runs to use and which not to use in the calculations.