How to and Why Use Respiration Rate in the Elite HRV App
If you are able to see the Respiration Rate option in the Elite HRV app, congratulations! You are part of a smaller segment of our user population that has access to this beta feature.
What is Respiration Rate?
Respiration is also known as "breathing rate." It refers to the number of breaths one takes per minute and is usually measured while at rest. Respiration includes both inhalation and exhalation.
Inhalation refers to breathing in - when our diaphragm contracts, moving downward. As a result, the space in our chest cavity increases and our lungs expand into that space. Air is then sucked in through our nose or mouth as the lungs expand. That air travels down our windpipe and into the lungs where oxygen in the air is exchanged with carbon dioxide from our body - oxygenating blood cells to be sent into circulation.
Exhalation refers to breathing out - when our diaphragm relaxes, moving upward and reducing the space in our chest cavity. While this is happening, our lungs are deflating like a balloon and this allows carbon dioxide-rich air to flow out of our lungs, through our windpipe and then out of our nose or mouth.
A normal, resting respiration rate is between 9 and 24 breaths per minute.
How does Elite HRV measure Respiration Rate?
Elite HRV measures respiration rate by counting the number of times your chest rises over a one-minute period. It does this by tracking the periodic and subtle respiration-induced motions of the face and upper chest in the video sequence.
The beta version of our camera-based respiration rate is available to a percentage of our user base. While we are in beta, the video records for calculation for the first 2 minutes of a reading; the video will continue to display but the actual recording stops in the background.
Like with HRV, it's more insightful to track your Respiration Rate daily, ideally at the same time each day. 2 or more consecutive days with elevated Respiration Rate and Heart Rate, paired with suppressed HRV, can indicate impending illness. We are working on a blog post to explore this phenomenon in greater depth.
You'll want to always make sure that you have the phone sitting on a still, flat surface, your face in the frame, and that lighting is good.
If the above factors are not met, then it will have issues with accuracy.
Please see this video:
To turn off this feature, you'll need to go to the settings menu which is found by tapping the profile picture or blue icon in the top right corner of the home screen.
From there, choose "Permissions."
Here, you can toggle off the Respiration Rate option.
The toggle for respiration tracking will still exist but will be turned off and the camera will not be activated or visible. This can easily be turned back on later if you decide to try out the feature again.
To note: this doesn’t change the settings in iOS camera access permissions. The camera does not activate if respiration tracking is turned off in our app, but if you like, you can disable camera access to Elite HRV in the iOS privacy settings for the camera.
Why Not Use RSA to Calculate Respiration Rate?
There is a phenomenon called Respiratory Sinus Arrhythmia (RSA) that contributes to your heart rate increasing as you inhale and decreasing as you exhale. When you're exercising, though, the sympathetic activity overrides that RSA expression, so you can't really capture it except when resting.
Additionally, the accuracy of this method for estimating breathing rate is higher for healthier, fitter people who tend to have a healthier/stronger connection between their nervous system and respiratory system.