HeartMath Heart-Rate Variability is a form of biofeedback that helps you build Coherence- an optimal physiological, coherent state where the heart, brain, and emotions align in harmony. Based on over 300 academic papers and recommended by health professionals worldwide, a few minutes of daily practice has been shown to reduce stress, increase energy and resilience, and improve mental clarity and performance.

For more information, please see this video, courtesy of the HeartMath Institute

https://www.heartmath.org/resources/videos/scientific-foundation-of-the-heartmath-system/