Techniques
Ways to breathe.
Five configurable patterns in the app. Plus explainer pages for the other widely-known techniques: what the research shows, what it doesn't, and which one to pick.
In the app
Resonance
Resonance breathing matches inhale and exhale at equal length and slows the breath to between five and seven breaths a minute. The rate comes from heart rate variability biofeedback research, reviewed by Lehrer and Gevirtz (2014). In a 2025 comparison of 84 students, Marchant et al. found that six breaths a minute raised HRV during the session more than box or 4-7-8 breathing did.
Box breathing
Box breathing splits the breath into four equal phases: inhale four seconds, hold four, exhale four, hold four. One cycle is sixteen seconds, just under four breaths a minute. The research is thin. Marchant et al. (2025) wrote that square and 4-7-8 breathing “have little empirical support”, and in their comparison six breaths a minute raised HRV during the session more than box breathing did. Its case is structure: four equal counts, easy to remember, easy to do with your eyes open.
4-7-8
The 4-7-8 pattern was developed by physician Andrew Weil from pranayama, the breath practices of yoga: inhale through the nose for four counts, hold for seven, exhale through pursed lips for eight. A cycle takes nineteen seconds, about three breaths a minute. The research is early. Vierra et al. (2022) measured HRV straight after three sets in 43 young adults and got mixed results; Marchant et al. (2025) found six breaths a minute raised HRV during the session more than 4-7-8 did, and that none of the patterns they tested meaningfully changed mood or blood pressure. Start with four cycles, sitting or lying down.
Extended exhale
Extended exhale is the plainest form of a pattern that 4-7-8 and cyclic sighing share: the exhale runs longer than the inhale. Here there are no holds and no top-up, only the ratio. Van Diest et al. (2014) had 30 people breathe with the exhale either longer or shorter than the inhale; the long-exhale pattern was rated more relaxing, and at six breaths a minute it came with more high-frequency HRV power. The app defaults to 4 seconds in and 8 out, with the inhale adjustable from 2 to 6 seconds and the exhale from 4 to 12.
Cyclic sighing
Cyclic sighing is the physiological sigh turned into a practice: a 2.5-second inhale, a 1.5-second top-up at the peak, then a 7-second exhale, repeated for five minutes. Balban et al. (2023) randomized participants to cyclic sighing, box breathing, cyclic hyperventilation or mindfulness meditation for a month. Cyclic sighing was the only breathing arm whose gain in positive mood, and whose drop in respiratory rate, differed significantly from meditation. HRV didn't change in any arm, and the study was too small to rank the three breathing patterns against each other.
Other techniques, explained
5–6 BPM
Coherent breathing
The same protocol clinical research calls resonance frequency breathing, under a different name.
Read
Pranayama
Alternate nostril
Nadi Shodhana. What the trials of nostril cycling do and don't show.
Read
Foundation
Diaphragmatic
Belly breathing. The mechanics, and what the trials show.
Read
CO2 tolerance
Buteyko method
Slow, light, nasal breathing. What the asthma trials and a Cochrane review show.
Read
Hyperventilation
Wim Hof method
Voluntary hyperventilation plus cold. What the studies measured, what they didn't, and the drowning risk.
Read
30 seconds
Physiological sigh
Double inhale, extended exhale. What the 2023 Stanford trial tested, and what it didn't.
Read