Experimental Mode

This mode is for exploring entrainment in non-standard situations. Results are tracked separately and won't affect your core averages or streaks.

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Breathe slowly and steadily and your heart rate starts to rise as you breathe in and fall as you breathe out. When that rhythm locks onto your breath, it’s called cardio-respiratory entrainment. This app measures it beat by beat and lets you see and hear it.

Set up. Wear a Bluetooth chest strap (moisten the sensor pads) and connect it. Sit upright and relaxed. Headphones give you the full sound.

Pick a pace. Each breath in and each breath out lasts 5–8 seconds. Try each pace a few times — the bars on the pace buttons then show which suit you best.

First 30 seconds. The circle stays still. Breathe naturally while your baseline is recorded.

Breathe with the circle. In as it grows, out as it shrinks. Gentle, easy breaths work better than deep or forced ones.

Watch it build. The meter moves from Settling through Aligning and Deepening to Entrained, and Ultra-stable when it holds. Below it, the timing lamps stay green while your timing holds; the left (behind) or right (ahead) side lights up when it starts to slip. Once you’re entrained, harmonic chords fade in and grow fuller the longer you stay.

Sound. Bells mark each turn of the breath. Tap the speaker during a session to set the binaural tone, bells, chords and an optional ocean wave.

If you drift, just come back to the circle. The score follows within a few breaths.

After each session, the grade (A–D) shows how well it worked. Track your progress on the insights page — turn on sharing in your profile.