Does slow breathing actually work?
Mostly trueClaim: "Slow paced breathing improves HRV and reduces anxiety"
Slow, paced breathing at roughly six breaths per minute (~0.1 Hz) brings heart rate and breathing into "resonance," sharply increasing heart-rate variability — a marker of a calm, well-regulated nervous system. Each person has a slightly different resonance rate (about 4.5-7 breaths/min). This is the mechanism behind HRV biofeedback, studied for anxiety, stress and performance. The evidence is moderate-to-strong and the effect is reliable. Named patterns like box breathing and 4-7-8 are popular variants; the validated active ingredient is slowing the breath and lengthening the exhale.
Sources
- Mechanism review: Lehrer & Gevirtz, Frontiers in Psychology (2014) 10.3389/fpsyg.2014.00756
- Slow-breathing systematic review: Zaccaro et al., Frontiers in Human Neuroscience (2018) 10.3389/fnhum.2018.00353