Product value
Generic apps use a fixed starting point
Many breathing apps default to 6 BPM because it is broadly familiar. That can be useful, but it is still an estimate rather than a personal measurement.
RHz is an Android resonance breathing app for people who want more than a generic calm timer. It uses guided HRV biofeedback sessions and external heart rate monitor data to identify the breathing rate that fits their own physiology.
Download RHz for Android and connect a compatible Bluetooth heart rate monitor to begin a guided resonance sweep.
Read the setup guide firstCurrent status
Hardware
Best with Polar H10
Whoop 5.0 also tested. External monitor required for accurate HRV sessions.
Protocol
Guided 20 min sweep
Identify your resonance breathing frequency instead of relying on a generic default.
Storage
Local only
Beat-to-beat session data stays on-device with manual export when you want it.
Output
CSV / JSON export
Portable data for your own records, experiments, or deeper review later.
Why this exists
RHz exists for people who want more than a calming timer. It is designed to help you identify your own resonance frequency, train with more confidence, and keep your session data private while the app stays local-first.
Why RHz
RHz is designed to make resonance breathing feel understandable and practical. Instead of asking you to trust a fixed pace, it gives you a clearer way to identify, revisit, and train at a breathing frequency that is better matched to your own body with real HRV feedback.
Product value
Many breathing apps default to 6 BPM because it is broadly familiar. That can be useful, but it is still an estimate rather than a personal measurement.
Product value
Your breathing response is not perfectly static. Sleep, stress, training load, and day-to-day physiology can all influence how a session feels and performs.
Product value
Guided sweep sessions, local-first data handling, and external sensor support make the app better suited for users who want a more deliberate HRV workflow.
How it works
The app is built to keep the workflow simple: connect a supported sensor, run a guided sweep, and return to sessions with a more personal target instead of guessing.
01
RHz works best with external Bluetooth monitors that provide dependable beat-to-beat timing. Polar H10 is the recommended setup.
02
A structured session explores a range of breathing rates so the app can identify a more personalized resonance breathing frequency.
03
Once you have a stronger starting point, future sessions can feel more deliberate, more consistent, and easier to track over time.
Compatibility
RHz is built around external monitor data because accurate HRV work depends on better signal quality than most casual breathing apps require.
Chest-strap ECG remains the clearest option for users who want the strongest timing accuracy during HRV biofeedback sessions.
Optical sensors may still be usable, but signal quality can vary more. Results may be less consistent than ECG-based hardware.
Some monitors may connect successfully but still provide lower-quality HRV data. Compatibility should be treated as descriptive, not guaranteed.
Who it is for
Privacy and trust
RHz treats session data as something you should control yourself. The current product direction is local-first, with manual export when you want to move or inspect your data elsewhere.
Trust summary
Why precision matters
Resonance breathing is not just slower breathing. The practical goal is to identify a breathing rate that feels more synchronized for you personally, then train with better consistency than a one-size-fits-all pace can offer.
Research and field experience both support the idea that personal resonance can vary across individuals rather than landing at one universal target.
Resonance frequency research
External monitor data gives RHz a stronger foundation for guided HRV sessions than a normal breathing timer can rely on by itself.
Why Polar H10 is recommended
RHz is meant to make the workflow clearer: identify a better starting rate, revisit it over time, and keep the data private and portable.
Balanced between research and usability
FAQ
Short answers for the current stage: the Android app is live, external monitor support matters, and the guide can help you get set up faster.
It is a guided breathing approach that helps you identify the breathing rate where your heart rate variability response becomes most synchronized. RHz is built to help you find and train at that personal frequency instead of relying on a generic 6 BPM default.
Most breathing apps pace everyone at the same rate. RHz uses external heart rate monitor data and guided sweep sessions to identify your own resonance breathing frequency and support more personalized training.
RHz works best with external Bluetooth heart rate monitors that provide reliable beat-to-beat data. Polar H10 is the recommended option. Whoop 5.0 has also been tested, while other devices may vary in HRV quality.
Yes. Session data stays on your device. RHz is designed around local-only storage, with optional CSV or JSON exports when you want to move your data yourself.
RHz is now live on Google Play for Android. You can download it directly from the store listing and review the setup guide if you want help choosing a compatible heart rate monitor first.
Not yet. RHz is currently available on Android. The focus right now is improving the Android app and supporting compatible external heart rate hardware.
Search guides
This is where the landing page gets more useful than a single homepage. If someone is comparing monitor types, looking for an HRV biofeedback app, or trying to understand why generic 6 BPM pacing feels limited, these pages answer that directly.
Explain why personalized resonance training is different from a generic slow-breathing timer.
Read guide
Show what measurement, session history, and better signal quality add beyond a simple pacer.
Read guide
Capture monitor-specific search intent from people who already care about ECG signal quality.
Read guide
Win educational searches from users deciding whether external chest straps are worth it.
Read guide
Reach people comparing dedicated breathwork hardware with a software-first workflow.
Read guide
Next step
The Android app is now live on Google Play. If you already have a compatible Bluetooth heart rate monitor, you can install it now. If not, read the guide first so you choose a setup that gives you reliable HRV data.
Install from Google Play, then use the guide to pair your monitor and choose the right session mode.
Read the setup guide firstReferences
Vaschillo, E. G., Vaschillo, B., & Lehrer, P. M. (2006). Characteristics of resonance in heart rate variability stimulated by biofeedback.
Steffen, P. R., Austin, T., DeBarros, A., & Brown, T. (2017). The impact of resonance frequency breathing on measures of heart rate variability, blood pressure, and mood.
Capdevila, L., Parrado, E., & Ramos-Castro, J. (2021). Is breathing at resonance frequency a stable individual trait?
Hayano, J. et al. (1996). Respiratory sinus arrhythmia and circulatory efficiency.