I used to track HRV on my Garmin 1030 and then I stopped.
Xert’s designation of “tired” does not seem to correlate to anything in the real world.
I have found paying attention to my own body is just as good for detecting fatigue as any device, especially something that requites a great deal of effort, and costs a great deal of money.
I track my hrv using HRV4Training but usually ignore it if I get a low score on one single day. I’ve always found my hrv is back to normal the next day. If I got two consecutive low scores and I was feeling fatigued I would take it easy that day. But that’s never happened.
What if you got two consecutive lows scores and did not feel fatigued?
I am guessing you would exercise. If so, then why bother with the tracking?
Good question 
. I’ll let you know when I have a good answer!! Might be a while. 
If relevant I can share some info on the tracking done by Polar. I have a Polar Vantage M that does sleep tracking and cardio load estimates as well. Because of training indoor I sometimes forget to have the watch also track the activity but when outside I always have the watch on as a backup for the Garmin.
Below is for example what their Cardio Load and Sleep report looks like:
Let me know if this is relevant in this topic or if you want to see other stats.
Like @Heretic I also tracked HRV for a while and stopped.
I even bought a device that would make it (purportedly) easy but that never worked reliably.
Then I used the iPhone as it’s been checked as ok for use with HRV4 app and eventually I stopped that. I kinda got bored checking it and wasn’t entirely sure it was telling me anything other than I’m about to die (low HRV compared to population comparisons all the time).
I am always keen on these kinds of things which means I buy stuff I end up not using/trusting.
I do kind of get the sense that after a few years of trying ‘amateur’ kit rather than proper lab testing, as an average person in an average house living an average life, unless I win millions on a lottery and then can access a serious coach/lab environment, that these half way solutions aren’t that great.
And then … the next time another thing comes along I’ll probably try that too … ahahahahahaha
Love those graphs.
In context @MartijnL … do you find you make different decisions about what to do based on the info it provides? (this is hard to write on messaging systems as it comes across all ‘challengy’ and it’s borne out of interest as I like data)
Right now I’m mainly going by feel as we’re not in tri season. Also: when this lockdown is lifted I’ll be commuting by bike. Even on days I don’t feel so hot I’ll still have to bike to work (34km one way) 
I’ve used the data only once to drive training/resting which was for my 1/4 tri at the end of '19 (all races I had planned last year got cancelled so not really been planning to peak at a specific moment).
Actually I used the Polar data and cross-referenced it with the Strava Fitness & Freshness info to try to work it out.
Hahaha thanks for the reply. I’m not feeling a lot of trust in the numbers but I have enjoyed attempting to quantify recovery. I guess at the end of the day it comes down to feel and the age old question of whether to train hard, easy, or rest, which has been covered in plenty of detail. I suppose I’ll just have to see what happens 
Whoop users - anyone else have trouble connecting the Whoop strap to SUF since the last firmware update?
