Heart coherence happens when the heart's electrical activity syncs with the brain's waves. A synced rhythm can produce higher cognitive functions, emotional stability, and states of calm (1). Additionally, returning to coherence frequently over time will raise HRV and vagal tone -- increased HRV is linked to longevity (2) and vagal tone shifts your nervous system to the "rest and digest" parasympathetic state (3).
Creating coherence is most easily done by breathwork, even 5 minutes twice a day will produce noticeable results. I use the Paced Breathing app (on iOS and Android) to time a ~4 second inhale and ~6 second exhale (see attached).
1) Sit up straight, close your eyes, and take 3 deep relaxation breaths - slowly in through your nose, deep into your lower lungs, and out through slightly opened lips like you are blowing through a straw.
2) Start app and breathe along to the pace you chose for at least 5 minutes.
3) That's it!
Over time, you might adjust the pace so your inhale and exhale are a few microseconds shorter or longer, as our lung sizes are all unique. You can see my pace in the screenshot attached.
1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4179616/
2) https://www.frontiersin.org/articles/10.3389/fphys.2020.566399/full
