Manual Input in HRV4Training

Blog post by Marco Altini

We have released Manual Input in HRV4Training, a feature which allows you to enter manually your heart rate and HRV data in the morning, as part of the questionnaire. 

​Below we cover the reasoning behind this feature, and how you can use it. 

To select manual input, go to Settings and change sensing modality. Then, simply tap "Enter Values" or "Measure" in the homescreen of the app, and the questionnaire will pop up, including an extra section where you can enter your resting heart rate and HRV as reported by another device. You can also edit your data from History, by tapping a measurement bar and opening the questionnaire for a given day.

Why Manual Input?

More and more devices are providing night HRV data based on optical measurements, with good accuracy. For example, in our recent tests comparing full night electrocardiography (ECG) against the Oura ring, Whoop band and Garmin Forerunner 955, day to day differences in HRV were very similar. 

In the graphs above you can see a comparison of ECG data and various wearables. The normal range does not match as different amounts of data have been collected, hence here we should only look at the actual scores, for about two weeks. We can see very good agreement in day to day changes for ECG, Oura and Garmin, with a larger error for Whoop, which is however providing data that is not too far since last year's update in how they compute HRV.

So far we have provided a direct link only to Oura. However, unfortunately, this link has resulted in very unreliable data connection due to Oura's API having quite a few problems. Additionally, it seems the API has been shut down for many users, probably due to the new subscription model or using the older ring.

Similarly, other wearables do not have APIs (e.g. Whoop) or we simply do not integrate with them (e.g. Garmin, Fitbit, etc.). 

Since we are talking about just two numbers here (resting heart rate and HRV, I have covered elsewhere how the full night average is the only meaningful parameter to use when measuring during the night), Manual Input makes it really simple to avoid all issues above, and allows you to enter your data as part of the morning questionnaire, regardless of the wearable you use. 

Why should I use HRV4Training if I already have a wearable?

Simply put, HRV4Training is the only platform that provides you with an analysis of your physiology that matches how this data is used in state of the art research and applied practice.

This means analyzing your resting physiology with respect to your normal range, and providing you with feedback regarding your acute (daily) and chronic (weekly) physiological state, in response to the various stressors you face. 

While in most tools you can look at your HRV numbers, these numbers are not contextualized with respect to other events (e.g. annotations you report in our questionnaire), or even with respect to your historical data.

Is today's reduction in HRV meaningful or just part of normal day to day variability? Entering your data in HRV4Training allows you to answer this question using published methods, which aim at effectively assessing your physiological response.

In the homescreen of the app you can easily see for example your daily scores with respect to your weekly baselines and normal ranges. In particular, the normal ranges are built using the previous 2 months of data, and allow you to quickly understand your current physiological response. 

You can learn more about why you should focus on your actual physiology as we do in HRV4Training, as opposed to made up scores provided in wearables, in this blog and this podcast. 

What data should you enter?

Wearables use slightly different methods and sensing locations to measure your HRV. These differences make it so that the data is not interchangeable, but the relative changes, which are the only aspect that really matters, are. Hence, it is important that if you wear a wearable, you try to use always the same device and place it on the same arm, finger, etc, since the relative position of the sensor with respect to the heart, can cause differences in pulse rate variability.

If you use a Whoop band, enter your night resting heart rate and HRV as found in the app. If you use an Oura ring, enter your average night heart rate (not what they report as resting heart rate, which is the lowest, enter the average instead) and your average HRV. If you use a Garmin, enter your night average HRV and your resting heart rate (Garmin uses the 30 minutes of the night in which it was the lowest).   

Do you need a wearable?

If you do not have a wearable and you have been measuring your physiology in the morning daily, you probably do not need a wearable and can save some money. 

If you are struggling with compliance for your morning measurement and would like to collect data passively, a wearable can help.

In any case, check out this blog to better understand some of the important differences between morning and night measurements of resting physiology.

I hope you'll find the update useful, thank you