Don't Hold Your Breath – Breathing Analysis with Polar H10 HR Monitor
A person's heart rate fluctuates based on factors such as activity, environment, and mental state. Additionally, heart rate variations occur on a much shorter timescale, with changes happening every few seconds. During inhalation, heart rate slightly increases, and it decreases again during exhalation, a phenomenon known as respiratory sinus arrhythmia. There are several reasons for this. Firstly, an increase in volume within the thoracic cavity (the space between the ribs) leads to a corresponding drop in pressure, which is counteracted by a rise in heart rate to regulate blood pressure.…
In plain words
Don't Hold Your Breath is a breathing analysis tool that works with the Polar H10 heart rate monitor to track respiratory sinus arrhythmia—the natural fluctuations in heart rate that occur during inhalation and exhalation. The software measures heart rate variability and breathing patterns to help users understand their autonomic nervous system response and stress levels. It is designed for people interested in exploring the physiological connections between breathing, heart rate, and their parasympathetic and sympathetic nervous system activity.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
A person's heart rate fluctuates based on factors such as activity, environment, and mental state. Additionally, heart rate variations occur on a much shorter timescale, with changes happening every few seconds. During inhalation, heart rate slightly increases, and it decreases again during exhalation, a phenomenon known as respiratory sinus arrhythmia. There are several reasons for this. Firstly, an increase in volume within the thoracic cavity (the space between the ribs) leads to a corresponding drop in pressure, which is counteracted by a rise in heart rate to regulate blood pressure. Secondly, breathing is deeply intertwined with the autonomic nervous system, which involves the opposing activation of the parasympathetic ("rest and digest") and sympathetic ("fight or flight") responses. By measuring heart rate variability and regulating our breath, we can gain insight into our stress response and learn to control it. The Polar H10 heart rate monitor provides basic heart rate measurements from a chest strap ECG, compatible with a number of fitness tracking apps that monitor heart rate zones wirelessly using bluetooth. The device also provides raw sensor data including an accurate measure of the timing between heartbeats (interbeat interval, with millisecond resolution) and 200 Hz accelerometer data. In this project this information is used to measure breathing rate and heart rate variability, and explore the relationship between the two.
Does the same job
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Through controlled breathing it is possible to regulate your body's stress response. I've built an app to measure and train this effect with a Polar H10 Heart Rate monitor. With every breath you take, you can set the pace of your breathing rate, measure your breathing control with the chest accelerometer, and see how heart rate variability responds.
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