Running power

Heart rate does not have any direct relevance to power, but it does have relevance to the FTP, which is the power produced at lactate threshold. So although you do not need the chest strap for power, you need it for the LT, unless you enter it manually.

Thank you. The performance index you linked to just confirms that the Epix shows way to hign a power. On this run at abolutely moderate intensity with an average of 5.15 min/km I had a power/weight at 4,66 watts/kg, wich at 57 years puts me somewhere between national and international elite. 

So without a chest strap I have to maintain my own FTP and Garmin will NEVER automatically suggest?

(this is not a massive problem for me, as intervals.icu makes a good estimate of FTP - but would like to see the official doc's/manual updated - Power is pretty useless without having FTP and being able to define zones etc).

It still seems a bit wrong, Critical Power (which is different, but similar to FTP), can definitely be determined without any reference to heart rate, why not simply auto calculate that based on best efforts in a power distribution curve over the previous 42 days or whatever?

No, Epix doesnt show way too high a power, it is using a different formula to define power so results in different numbers, thats all.

That performance index is based on a formula which is very similar to what Stryd use. It doesnt mean it is 'more correct'.

3673816 said:

So without a chest strap I have to maintain my own FTP and Garmin will NEVER automatically suggest?

Currently it is indeed so - you need the chest HRM for the LT auto-detection (see the article How Is Lactate Threshold Measured by My Garmin Device? | Garmin Customer Support). Perhaps it may change in future.

You can still hard code the power zones manually. You can suggest the use of Critical Power to Garmin at Share Ideas | Garmin, but as far as I see it is quite a bit more complicated tog get it, than getting the LT / FTP. Perhaps there are simpler methods, but the one I found would not be very attractive for users:

Critical power is typically established by having an athlete complete between three and five separate high-intensity exercise tests on different days, during which they are asked to sustain a fixed external power output for as long as possible – eg time trial conditions.

I think people serious about their running will use a HRM chest belt anyway, since having the LT, HRV, respiration rate, and running dynamics data is important for them too. Still worth of suggesting the Critical Power based zones to Garmin, though.

I would like to be able to change the "wind factor" - my experience is the effect of wind is over estimated (I live in a very windy location). I know you can turn on/off the taking wind into account - I want it on, I just want it to mean a little less.

(Would be nice if wind was taken into account when calculating VO2 Max as well - but this is a different story)

3673816 said:

why not simply auto calculate that based on best efforts in a power distribution curve over the previous 42 days or whatever

That would work, but Garmin doesn't give you a power curve for running yet. We have it for cycling, so I expect we'll eventually get it for running.

Right now, the watch is using HRV metrics to determine the second respiratory threshold, a proxy for lactate threshold. Since HRV metrics in that range of efforts are almost completely subdued, you need a good quality chest strap that sends RR (like Polar H10 or HRM-Pro) to get quality results.

Alternatively, you can do a field test FTP (run as hard as you can, but steady, for 30mn continuously, take the last 20mn average power).

Is any new calibration of power W for running in new FW? I have still nonsence data from wrist measurement. All my run are in Zone5 (Epix measurement) against mix Zones with Stryd. 

You are right and I understand different Watts between Stryd and Garmin measurements. But what I do not understand is why my power in Garmin is still in Zone 5. I have set CP in Stryd 239W and in Garmin 350W. But in slowly run (Stryd in Zone 1-2) still show over 350W. When I do speed running (Stryd Zone 5) Epix show aprox 430W...That means still in red Zone 5...