Coros x HRV4Training

choose between morning ECG or night PPG for your measurement

Excited to announce that we have just finalized the integration between Coros and HRV4Training, which will allow you to use your Coros watch ECG functionality to take a morning heart rate variability (HRV) measurement, and then read it in HRV4Training for interpretation.

December update: the integration now allows you to choose between morning measurements using ECG and night PPG data. The night data has resulted reliable in our test, and is a viable alternative to other solutions on the market (Oura, Whoop, Garmin, etc.).

Comparison of night HRV between an Oura ring and a Coros Apex Pro 2.

Setup

In order to be able to use this integration, you will need:

• HRV4Training app for iOS or Android

• Coros watch that supports the morning HRV test, via ECG (for example the Apex Pro 2) or night HRV data via PPG.

Once you have the required software and hardware, head to the Settings page in HRV4Training and scroll down until you see the integrations section, then link it to Coros using your credentials. Coros will then become the default data acquisition mode (instead of Camera or other methods you might have been using):

Morning measurement

Once you have configured the integration, you can take your morning measurement with the watch and read it in HRV4Training. The process works as follows:

1. use the HRV Test app on the Coros watch, to take an ECG

2. sync your Coros watch to the Coros app

3. read your data in HRV4Training, from the homepage of the app

1. use the HRV Test app on the Coros watch, to take an ECG

As discussed here, we recommend taking your morning measurement while sitting, which makes it more sensitive and therefore more useful than measurements taken while lying down or collected during the night (see this other blog for an overview of the research on this). These are also the instructions provided by the Coros app:

2. sync your Coros watch to the Coros app

The integration between Coros and HRV4Training happens via APIs, and therefore HRV4Training does not communicate directly with the Coros watch, but communicates with Coros’ servers. This means that after taking the ECG measurement, you will need to sync the Coros watch with the app, so that the HRV data appears in the app.

Note that Coros provides an HRV index, which goes from 0 to 100, while we will read the actual HRV data, as rMSSD, and bring that number, together with your resting heart rate, to HRV4Training.

3. read your data in HRV4Training, from the homepage of the app

The last step is simply to read the data from Coros, instead of taking your measurement via the HRV4Training app.

We will also read bedtime and wakeup time, in case that data is available.

Night measurement

For a night measurement, make sure to de-select the switch in the app Settings, as shown below.

Undecided on which one to use?

My preference is a morning measurement: it reflects better your readiness for the day, as opposed to your behavior the previous evening / night. In addition, it is far from stressors, which makes it ideal to determine your response. It is also the only way to measure while sitting up, which is a preferable protocol if we want to capture physiological stress with higher sensitivity.

Below I discuss them in more detail.

Please note that we do not read workouts data from Coros, and the preferred integration for workouts data remains Strava.

I hope you will enjoy this new feature and integration. Thank you for your support

Marco holds a PhD cum laude in applied machine learning, a M.Sc. cum laude in computer science engineering, and a M.Sc. cum laude in human movement sciences and high-performance coaching.

He has published more than 50 papers and patents at the intersection between physiology, health, technology, and human performance.

He is co-founder of HRV4Training, advisor at Oura, guest lecturer at VU Amsterdam, and editor for IEEE Pervasive Computing Magazine. He loves running.

Social:

• Twitter: @altini_marco.

• Personal Substack.

• Strava.

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