For the curious
No empty promises. No pseudoscience. Just decades of applied physiology research.
UnderstandThe key concept
Your heart doesn't beat regularly. The interval between two beats varies constantly. This variation is called heart rate variability (HRV).
High HRV (variable) indicates a flexible nervous system, capable of adapting to stress. It's the sign of a healthy body.
Low HRV (flat) suggests a rigid nervous system, stuck in alert mode. It's often a sign of chronic stress.
Heart coherence is an optimal state where your heart rate variation becomes regular and sinusoidal, synchronized with your breathing.
Large variations between each heartbeat. Your nervous system adapts in real time.
Almost no variation. Your system is stuck, unable to adapt.
Smooth wave synchronized with breathing. Optimal recovery state.
The mechanism
At this precise frequency, your breathing enters into resonance with your cardiovascular system. It's the optimal resonance frequency for most adults.
Heart coherence stimulates the vagus nerve – the main "brake" of the nervous system. It sends a calm signal to your entire body.
Heart rate slows. Blood pressure decreases. Cortisol drops. The nervous system shifts into recovery mode.
The numbers
after 4 weeks of practice (HeartMath, 1998)
6 breaths/min = peak HRV amplitude
in the 2023 meta-analysis (Springer)
since early work on the vagus nerve
Questions
Heart coherence has been studied since the 1990s, notably by the Institute of HeartMath. Studies are published in journals like Applied Psychophysiology and Biofeedback, International Journal of Psychophysiology, and Global Advances in Health and Medicine.
It's the resonance frequency of the cardiovascular system for most adults (it can vary between 4.5 and 7). At this frequency, heart rate variability amplitude is maximal, which amplifies vagus nerve activation.
A healthy heart is flexible and reactive. It constantly speeds up and slows down in response to your environment. This "chaotic" variability is the sign of an adaptable nervous system. A flat, regular HRV indicates a rigid system, often under chronic stress.
No. Sloow is a wellness tool based on relaxation and stress management. It is not designed to diagnose, treat, or prevent medical conditions.
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