Every heart has a resonance frequency.
Most breathing apps don't know yours.
There is one breathing pace — specific to your body — at which heart-rate variability amplifies into a single clean oscillation. Heart Resonance measures it with your chest strap or arm sensor and trains you there.
Android · Google Play ↗ · iOS coming soon
What makes it different
Heart Resonance exposes the full methodology that most wellness apps hide behind a single score.
Real sensor data
Connects to standard Bluetooth heart-rate sensors — Polar, Garmin HRM, Wahoo. Raw R-R intervals, not wrist-PPG guesswork.
Adaptive pacer
An ASSESS → REFINE → HOLD protocol tests candidate breathing rates against your live heart signal and converges on yours.
Shaffer six-criteria coherence
Peak power, single-peak dominance, LF concentration, peak height, SDNN, and RMSSD — all visible, every session.
Full session export
Every R-R interval, every breathing cue, every score. CSV export for your own analysis. Your data stays on your device.
One-time unlock
Lifetime of sessions. We think recurring subscriptions for breath training are absurd.
Built for clinicians too
Methodology transparent enough for HRV biofeedback practitioners. Read the coach page →
The three things to know
Your heart rate naturally oscillates with your breath
Inhale, it speeds up. Exhale, it slows. This is respiratory sinus arrhythmia (RSA) — a direct readout of vagus-nerve activity. A bigger RSA oscillation means better autonomic flexibility. More on RSA →
One breathing pace makes that oscillation enormous
Your cardiovascular system has a resonant frequency — set by the baroreflex loop between your heart and arteries. Breathe there and the RSA oscillation amplifies dramatically. For most adults it falls between 4.5 and 6.5 breaths per minute. The exact number is yours. Why there is no universal "6 BPM" →
Ten weeks at your frequency changes baseline HRV
This is not just relaxation. Resonance frequency breathing practiced 20 minutes daily for eight to ten weeks has repeatedly produced measurable improvements in baseline HRV, baroreflex gain, and vagal tone. See the research →
"The frequency is not prescribed. It is discovered."
Free tools
Explore the concept before you install anything.
Web breath pacer
Adjustable 3 – 10 BPM pacer in your browser. No sensor needed. Great for an immediate taste of coherence breathing.
Resonance frequency estimator
Starting-point estimate of your personal frequency based on age and height. The app measures it for real.
HRV glossary
RMSSD, SDNN, LF/HF, coherence, baroreflex, vagal tone — plain-English definitions for everything.
App comparison
How Heart Resonance stacks up against HeartMath, Elite HRV, Welltory, and the rest. Honest take.
From the blog
Long-form writing on HRV, breathing, and measurement.
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Apr 2026
What HRV actually measures (and what your wearable gets wrong)
Wrist PPG, morning readiness scores, "stress" values — there's a gap between what consumer wearables report and what the heart-rate signal actually contains.
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Apr 2026
Why there's no universal "6 breaths per minute"
The Vaschillo protocol, baroreflex loop mechanics, and why the pace that works for you may not work at all for the person next to you.
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Apr 2026
Heart coherence in plain English
A guided tour of Shaffer 2020 — the six criteria that quantify coherence, what each one means, and why any single-number "coherence score" is a simplification.
Ready to find yours?
Pair a heart-rate sensor, run the 12-minute assessment, and get your personal resonance frequency — then practice there.