1. Before You Start
What You Need
- An Android phone with Bluetooth
- An ECG chest strap (Polar H10, Garmin HRM-Pro, or Wahoo TICKR recommended)
- A quiet place where you can sit still for 10–20 minutes
Best Practices for Accurate Results
- Stay still. Movement introduces noise into the heart rate signal. Sit comfortably or lie down — don't walk around mid-session.
- Don't test right after exercise. Your autonomic nervous system needs time to settle. Wait at least 30 minutes after a workout before running a sweep.
- Breathe through your nose if possible. Nasal breathing naturally supports a slower, more consistent rhythm.
- Same time of day, same posture. Your resonance frequency can shift depending on time of day, hydration, stress, and posture. For the most consistent tracking, try to test under similar conditions.
- Minimize distractions. Close your eyes if it helps. The app handles the pacing — you just follow along.
2. Connecting Your Hardware
Tap CONNECT on the main dashboard to scan for nearby Bluetooth heart rate monitors. Select your device from the list. Once connected, the banner turns green and shows your device name.
Important NoteThe app works best with an ECG chest strap. Optical wrist sensors broadcast smoothed heart rate data that lacks the beat-to-beat precision the algorithm needs.
3. Choosing a Session Mode
RHz offers three modes depending on how much time you have and what you're trying to do.
Find My Frequency (Full Sweep)
What it does: Runs a complete resonance frequency protocol. The app guides you through a 2-minute natural breathing baseline, then a coarse sweep across five breathing rates (6.5 down to 4.5 BPM), followed by a fine sweep that zeros in on your personal optimum with 0.1 BPM precision.
- Your first session — this is where you discover your frequency
- Every few weeks to check if your frequency has shifted
- After a major lifestyle change (new training block, travel, sustained stress)
Tip: If you have the time, this is always the most thorough option. The full sweep gives the algorithm the most data to work with.
Quick Tune (Fine Sweep)
What it does: Skips the wide coarse sweep and tests a narrow band of five frequencies centered around a typical range (5.3–5.7 BPM). Still includes the 2-minute natural breathing baseline.
- You've already done a full sweep and just want a quick recalibration
- You're short on time but still want a targeted result
Smart Start (Adaptive)
What it does: If you're a new user with no history, it runs a discovery protocol. If you have prior sessions, it starts at your historically best frequency and continuously fine-tunes — dwelling at the current best, probing neighboring frequencies, and adopting any that perform better.
- Daily resonance breathing practice at your known frequency
- Pairing with meditation — track your HRV in real time to see efficacy
- Long sessions where you want the app to adapt as your nervous system responds
Tip: Toggle Indefinite Mode on for open-ended sessions. The app will keep optimizing for as long as you breathe. After a Full Sweep or Quick Tune, if Indefinite Mode is on, the app automatically transitions into adaptive mode at your discovered frequency!
4. Pre-Session Setup
Posture
Choose Sitting, Standing, or Lying Down. This is logged with your session so you can track whether posture affects your resonance frequency over time. For the most relaxed and consistent results, sitting or lying down is recommended.
Session Goal
Your goal adjusts the inhale-to-exhale ratio of the breathing pacer:
| Goal | Inhale | Exhale | Use Case |
|---|---|---|---|
| General Calm | 4.0s | 6.0s | Default — balanced autonomic support |
| Deep Sleep Wind-down | 3.5s | 6.5s | Extended exhale biases toward parasympathetic activation |
| Pre-workout Focus | 4.5s | 5.5s | Slightly shorter exhale for a more alert, ready state |
5. Feedback Options
Customize how the app communicates the breathing rhythm. Toggle these on the main dashboard.
Visual Pacer
An on-screen animation that expands and contracts to guide your breathing. On by default.
Haptic Engine
Gentle vibration pulses that mark the inhale/exhale rhythm. Useful for closed-eye sessions. On by default.
Binaural Cues
Stereo audio tones that shift frequency between inhale and exhale. Off by default.
Recommendation for Audio: If you turn binaural cues on, keep the volume as low as possible — just barely audible. It's most effective as a subtle background stimulus.
6. During a Session
- Baseline phase (2 mins): Breathe naturally. The app measures your resting HRV before guided breathing begins.
- Sweep phase: Follow the pacer. The app tests different breathing rates and scores each one using spectral analysis of your live heart rate data.
- Result: The app identifies your optimal resonance frequency at the end.
Gauge Sensitivity
In settings, you can adjust how responsive the live HRV gauge is:
- High: Reacts to small changes (15% shift). Good for experienced users.
- Medium: Balanced (25% shift). The default.
- Low: Only responds to large changes (40% shift). Less distracting.
7. After a Session
History View
Tap the history icon to see all past sessions. Each entry shows the date, goal, duration, discovered frequency, and RMSSD change (green = improvement, red = decline).
The frequency distribution chart at the top stores the full frequency-versus-score landscape from richer sessions instead of just a single winner dot. Over time, the bins that consistently perform well rise together into a more useful confidence landscape, which makes it easier to spot where your resonance frequency is actually stabilizing.
Long-Term Trends
Tap the analytics icon on the dashboard to see long-term trends (requires 2+ sessions):
- Resonance Convergence: Tracks your optimal frequency session over session. A narrowing line means stabilization.
- HRV Gain Trend: Shows the RMSSD improvement for each session. Green bars indicate HRV improved during the session.
- Autonomic Baseline: Tracks your resting baseline RMSSD over time. An upward trend suggests your resting autonomic tone is improving.
Export & Import
From the history screen, export your data as CSV (for spreadsheet analysis) or JSON (for backups). You can easily import this data later if you switch phones.
Tips for Getting the Most Out of RHz
- ✓ Consistency matters more than session length. A 12-minute Quick Tune every day is more valuable than one 60-minute session per month.
- ✓ Watch your Autonomic Baseline. If your resting RMSSD is trending upward over weeks, your training is working.
- ✓ Recheck your frequency periodically. It can shift with fitness changes, stress, sleep, and aging. Run a Full Sweep every few weeks.
- ✓ Use Adaptive mode for daily practice. Smart Start is the fastest way to get into a productive session based on your known history.
- ✓ Pair with meditation. Run an Adaptive session quietly in the background to see if your practice drives a measurable autonomic response.
Privacy Promise
All data stays on your phone. There are no accounts, no cloud sync, and no data collection. Your sessions, heart rate data, and resonance frequency results are stored locally and never leave your device.
Related Reading
Resonance breathing app
A category page on why personalized breathing targets matter more than generic pacing.
HRV biofeedback app
A practical explanation of what measurement adds beyond a breathing timer.
Polar H10 breathing app
A focused page on why chest-strap ECG remains the recommended setup.
ECG vs PPG for HRV biofeedback
A sensor-quality comparison for users choosing between optical and ECG workflows.