Cardiac coherence

Cardiac coherence is a form of breathing exercise which alternates approximately 5 second-long in and out breaths. It tends to create a synchronization of heart and breath rythms, maximizing heart-rate variability. Cardiac coherence tends to be milder in its effects than other forms of breathing exercise, rarely inducing intense modulations of lived-experience, and is perhaps not an emergent modality per se, but it has a variety of health benefits. According to Nashiro et al. (2025),

slow breathing around the baroreflex frequency (6 breath per minute, 0.1 Hz, or 10 s/breath) generally activates parasympathetic vagus nerve activity, suppresses sympathetic/noradrenergic activity, and increases heart rate oscillations. Repeated practice of baroreflex-frequency breathing to increase heart rate oscillations promotes a number of health benefits, including long-term emotional health and positive effects on cardiovascular diseases.

This breathing practice may have additional miscellaneous benefits like potentially delaying or slowing-down the progression of Alzheimer's disease.

Risks and contraindications

Note that while cardiac coherence does not usually involve hyperventilation, and has in principle little to no inherent risks compared to high-ventilation breathwork practices, hyperventilation can be dangerous and contraindicated for individuals with certain conditions such as neurological, respiratory, or cardiovascular diseases, epilepsy, mental health issues (e.g. PTSD, anxious tendencies, or panic disorders), pregnancy, and more. Please consult with a doctor before you engage in such practices if you think you might have a contraindication.