HRV data comparison between Garmin and HRV4Training

I wrote about HRV in the past and how I found it an extremely useful metric. As HRV4Training website put it:

Heart Rate Variability (HRV) insights to help you quantify stress,
better balance training and lifestyle,
and improve performance

In this post, I want to compare HRV data collected between Garmin and HRV4Training, as well as the "readiness score" these two sources produce. The data is for two months period, in which I was training for a marathon, and for that time I use Garmin Fenix 7 with an alpha/beta version of the software.


In this chart, you can see HRV values between Garmin and HRV4Training

  • HRV4Training was taken every morning for 1 min.
  • Garmin was measured during the night.

Some additional background:

  • On 11 Sept I did a half marathon, in very hard conditions - hot and humid weather.
  • Between 14-17 Sept I got a stomach virus so I was feeling pretty bad for 3-4 days.
  • On 26 Sept I did a full marathon pretty much all out.

You can see when I was sick and after the races my HRV was pretty low. In my opinion, trendings are very similar, especially in the last 3 weeks around the races and sickness.


Since HRV is mainly about how stressed you are and how hard you should train I've decided to compare also training readiness functionalities.

  • HRV4Training is giving you 3 states: Proceed as planned, Limit intensity and Take it easy, I marked these as 3,2,1 points accordingly.
  • Garmin Training Readiness is a bit more complex and includes more things than just HRV status, like sleep and time since the last training. Training Readiness here is a value between 1 and 100, to normalize the data 1-24 is 1, 25-49 is 2, and 50-100 is 3.


Even though I have a Garmin device with HRV capabilities I still find HRV4Training useful, since it has questionnaire so in that way you not only can see the HRV value but also has context around it. And I believe having a context is very important.

On top of that HRV4Training costs only 10 euros ( or less ) compared to high-end Garmin devices, which means you can buy a cheaper device and still enjoy that functionality.

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Created by:Stoyan Delev | Build with NewsKit