What is my heart rate (HR)? Your heart rate is the number of beats of your heart per minute. Our heart does not beat to a fixed, regular rhythm like a metronome. Rather, the rhythm of a healthy heart is irregular, with the intervals between successive heartbeats constantly varying.

This variation between heart beats is called heart rate variability (HRV). HRV is an important indicator of an individual’s capacity to effectively adapt to stress and environmental demands. The statistics section of the app shows your HRV scores throughout the exercise.

Determining a "normal" HRV range is difficult: your own minimum and maximum values depend on several factors, such as your age, hormones, circadian rhythm, lifestyle and general health. Therefore, it is best to compare your numbers with your own baseline values.

There are many different ways to calculate HRV (time-domain, frequency-domain analysis...). We use the difference between HR max and HR min to calculate HRV. For that reason, HRV is expressed in bpm. So if your HR goes from 70 to 50 during one breathing cycle, the difference will be, for example, 20 bpm. Based on our calculations, HRV typically varies between 0 and 20, with higher being better 😊.

Breathing slowly is one of the best ways to increase HRV and reduce stress. Of course, if your HRV is rather low, it doesn't mean you're doing "bad. First, take a look at what your HRV is when you're not paying attention to your breathing. Then you can look for the moonbird exercise that works best for you to get that HRV as high as possible.

You might ask yourself "Is this a good HRV score? Am I making any progress?"
​
When it comes to your HRV score, keep in mind that it is more important to develop your own personal baseline than to compare yourself with the general population. HRV scores depend on many factors such as age, weight, diet, medication, stress levels etc. and therefore vary greatly compared to other people.
​
This is why it is far better to compare yourself to who you were yesterday than to who others are today. moonbird is not intended for continuously tracking your HRV throughout the day.
You can however use it to calculate your baseline HRV. By doing your breathing exercise with our device at the same time every day, such as in the morning immediately upon waking, you can see how your HRV is improving over time.

Since HRV is such a sensitive measure, it might take a while before you will see improvements. It can take weeks, sometimes even months. This is completely normal. Don't let this discourage you from practicing your breathing!

What is heart coherence? Coherence is the degree of synchronization between your heart rate and your respiratory rate. Heart coherence is an indication of whether your breathing and heart rhythm coincide nicely; when you breathe coherently, your heart rate changes in sync with your breathing: your heart rate speeds up on the inhale and slows down again on the exhale.

The colors in the coherence graph in the app indicate how coherent you are breathing through the following distribution: