B
practicestress
Slow-Paced Breathing (~6 breaths/min)
Best evidence: B — Moderate evidence for Anxiety & physiological stress markers
Breathing at about six breaths per minute to shift the nervous system toward calm — well-supported for stress and cardiovascular markers, free, and fast-acting.
Graded outcomes
What the evidence says
B
Anxiety & physiological stress markers
Moderate evidence · Good evidence, with some gaps or inconsistency.
- Effect size
- SMD = −0.45 for systolic blood pressure; moderate effect on heart-rate variability (RMSSD, SDNN); individual RCTs show large within-session anxiety reduction (Cohen's d up to −1.46).
- Evidence base
- Multiple independent meta-analyses on cardiovascular/HRV outcomes; anxiety-specific meta-analytic pooling is thinner than the cardiovascular literature, though individual RCT evidence is consistent.
- Population
- Effects are well-established in healthy non-hypertensive adults; more variable in those with existing cardiovascular conditions or on antihypertensive medication.
- Dosage / protocol
- ~6 breaths per minute (a 4-second inhale, 6-second exhale is one common pattern), sessions of 5+ minutes, done acutely (a single session) or as a regular practice.
- Contraindications & cautions
- None significant for healthy adults; those with cardiovascular conditions should consult a doctor before structured breath-rate training.
Citations
- 1.Mindfulness (2023), Springer — Meta-analysis
- 2.PMC12301348 — Meta-analysis
- 3.Neuroscience & Biobehavioral Reviews (ScienceDirect) — Systematic review
Mechanism
How it works
How Slow Breathing Calms the Nervous System
Extended exhalation stimulates the vagus nerve, which carries the signal to the brainstem to shift the autonomic nervous system toward its calmer, parasympathetic mode — slowing heart rate and increasing heart rate variability within about 60–90 seconds.
Citations
- 1.Mindfulness (2023), Springer — Meta-analysis
- 2.PMC12301348 — Meta-analysis
Compared with