Coherent breathing, also called resonance or resonant frequency breathing, is a slow-breathing technique paced at about five to six breaths per minute, with equal inhales and exhales of roughly 5.5 seconds each. Breathing at this rate synchronizes heart rhythm and respiration, maximizing heart rate variability.
Around five to six breaths per minute, the rhythms of breathing, heart rate, and blood pressure synchronize, a phenomenon researchers call resonance. Breathing at this rate stimulates the baroreflex, the body's blood pressure feedback loop, and produces the largest swings in heart rate variability (HRV) a person can generate. Higher HRV is associated with better stress resilience, emotional regulation, and cardiovascular health, which is why coherent breathing is also called resonance or resonant frequency breathing.
Coherent breathing uses no breath holds. You simply inhale for about 5.5 seconds and exhale for about 5.5 seconds, ideally through the nose, producing roughly 5.5 breaths per minute. The exact resonance frequency varies slightly between individuals, typically falling between 4.5 and 6.5 breaths per minute, but 5.5 is an effective average for most adults. The breath should feel smooth and unforced rather than deep or effortful.
Psychiatrists Richard Brown and Patricia Gerbarg helped popularize coherent breathing in clinical settings, using it with survivors of the 2004 tsunami and the September 11 attacks. Controlled studies have since found that slow breathing at this pace, sometimes combined with yoga, can reduce symptoms of major depression, generalized anxiety, and PTSD. Reviews of slow-paced breathing research consistently report reduced self-rated stress and anxiety, though many trials are small and more rigorous studies are needed.
Coherent breathing is the core of heart rate variability biofeedback, an approach studied extensively by researchers like Paul Lehrer and Richard Gevirtz. Each slow inhale accelerates the heart and each exhale slows it, exercising the baroreflex like a muscle. Over weeks of practice, resting baroreflex sensitivity and vagal tone improve, which may explain documented benefits for blood pressure, asthma, and emotional regulation. Ten to twenty minutes a day is the dose used in most clinical protocols.
Box breathing inserts four-second holds after the inhale and exhale, making it a focusing tool for acute stress, while 4-7-8 breathing uses a long exhale and hold to wind down quickly for sleep. Coherent breathing has no holds and no asymmetry; it is gentler and designed for longer, sustained practice. Many people find it the easiest slow-breathing technique to maintain for ten or more minutes, making it well suited to daily HRV training.
Sit or lie comfortably, breathe through your nose, and let your belly expand on the inhale. Pace yourself to roughly 5.5 seconds in and 5.5 seconds out; a chime or visual pacer helps enormously, which is why guided apps like DeepBreathe use voice and bell cues to keep you on rhythm without counting. Start with five minutes once or twice a day and build toward twenty. Benefits accumulate with consistent daily practice over several weeks.
