This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Daily suggestions and heart rate zones

There are a line of different sorts of training types.

  • Basic
  • Recovery 
  • Sprint
  • Tempo
  • Long run

There is a lot of information about how daily suggestions work. Garmin wrote about it in detail here.

We all know that you can pick between two target types. Suggestions based on Pace, or based on heart rate.

However, I wonder how the algorithm for heart rate zone works. And I ask because:

Case 1: I have been using the FR 945 for 3 years and was pretty settled with a stabile definition of HR zones. As I changed over to FR 955, these zones weren't transfered, and I either had to define the zone manually, or let the watch "learn" my zones through the automatic detection. I wanted to go for the latter (considering my zones do change with age). But i have noticed that the HR Z for "basic" workout are fairly lower than my zone before.

Case 2: My wife has recently moved from FR 245 to FR 255S. Her HR range is HRrest 50 - HRmax 207. We have always had trouble to use "science" to define her zones, which has been hard because the HR range is so big. Her trouble is that daily suggestions use HR that force her to run much slower than her regular pace. 

We have both been trying to adjust our HR zone 1-2-3, but without seeing any differences in the daily suggestion. 

For example. 

Case 1: When i have a basic workout, my HR is to be 145 (my HRmax is 191ish) which is around my HR zone 3.5.
Case 1: When my wife has a basic workout, her HR is to be around 160 (her HRmax is 207ish) which is around her HR zone 2.1


So, what is the logic?

Does the HR change over time? Similiary to what we see with pace?

Has anyone else had experiences with daily suggestions that puts you off because of the pace/HR requirements?

  • 955 seems to have slightly different algorithm for HRmax and it gets updated up or down, even if I don't reach that level during a workout. HRmax influences VO2 Max and I think (I'm not sure but it was pretty evident in the 945) they together set the HR targets for the daily suggestions. I used the 945 for several years, and the "base" daily suggestions heart rate has always been 68-69% of the HR Max. 955 seems a little different. I would modify the HRmax setting in the watch so that you get in the right zone and then let the new watch adjust over time HRmax and VO2max with the auto-detection. I don't know how you set your zones, but I set them as % of lactate threshold and leave all the percentage ranges as default and all my "base" runs end up recommended pretty much in the middle of zone 2 and that feels correct.

  • We have both been trying to adjust our HR zone 1-2-3, but without seeing any differences in the daily suggestion. 

    It should be your MHR that matters.

  • I have similar issues to your wife. My RHR is averaging 47 bpm (goes as low as 41), and my MHR is 209 as of late (and likely closer to 215). I'm in my mid-40s, and I don't think the algorithms for auto-detection work very well for me, probably because they are weighted to work for most people instead of outliers. I think the fits get into a bad local minimum for folks hitting HR above 205 or so.

    One other thing I have noticed is that letting my watch detect my MHR not only yields much lower MHR (usually between 190 and 203, which is quite a bit lower than I hit routinely on uphill sprints) but also changes my target HR for Firstbeat daily suggested workouts. E.g., base THR will go from 155 to 150. At 150, I get beeped at if I exceed 164bpm (very easy, it's hilly everywhere around me). Last summer due to heat acclimation my MHR was autodetected at 220 and my LTHR was in the low 190s, so my THR for a base run was 165bpm, and I didn't get beeped until I crested 178bpm (for base!).

    TL;DR: Garmin autodetect of MHR doesn't work great for people with broad big MHR and low RHR. Firstbeat workouts seemed to be influenced by MHR, not just by LTHR.

  • Here is Garmin's blog post on how the real-time stamina feature (also a Firstbeat algorithm) works: https://www.garmin.com/en-US/blog/outdoor/introducing-the-garmin-real-time-stamina-feature/

    It sounds like an accurate MHR is the most important thing in properly determining stamina/stamina potential drain (which drives training load which in turn drives workout categorization). LTHR and LTHR based zones can be a useful tool for training, but ultimately I don't think the watch is really using those zones (or any HR zones).

  • I had same issue. Did a little googling, and found the following, which I thought made sense, and worked for me.

    Autodetected RHR is not very useful. Mine is 45….but it’s only that low when I’m sleeping or lying down… not really relevant for running.

    instead, self measure your standing resting heart rate, and input that.

    choose %HRR method, manually enter MHR if you don’t like the auto detect value.

    Turn off auto detect RHR and MHR.

    Use default zone settings.