Resonant Breathing

This is a heart-rate-adaptive, extended exhale protocol, breathwork app.
Heart-rate adaptive: when heart rate is available, each breath cycle will be synced in length to a multiple of the heartbeat.
Extended exhale: while this is configurable and quite flexible, this app is specifically built to facilitate having an exhale that is longer than the inhale.
Breathwork: The use of breathing as therapy, particularly changing the breathing rhythms.

What sets this app apart:
Breath phases are measured in heartbeats, so your breathing rhythm naturally adapts as your heart rate changes - while always staying synchronised to your heartbeats. This aims to achieve resonance between breath and heart: when the longer rhythm of the breath is a multiple of the faster rhythm of the heart. Research suggests that this cardiorespiratory synchronisation is associated with improved relaxation and cardiovascular function. The app also supports progressive lengthening: your breath durations gradually extend as you relax, easing you into deeper breathing over the course of the session.

How to use:
- On Apple Watch, simply start a session and follow the animated flower - it opens as you inhale and closes as you exhale. Gentle haptic pulses mark each transition. No counting required; just breathe with the rhythm.
- On iPhone, the app uses a steady 60 BPM baseline for a consistent, calming practice.
- Breath lengths are highly configurable; slower breaths lead to deeper relaxation but should still feel comfortable - experiment to find what's right for you.