5.5 Breathing…What is it? Why it matters?

I love a good study…I was researching 5.5 breathing and came across this article. What does it mean? This study shows increased heart rate variability with 5.5 breaths per minute (5.5 seconds on inhale and 5.5 seconds on exhale). What does increased heart rate variability mean? It is considered a sign of a healthy and adaptable autonomic nervous system. What does that mean? Helps us respond effectively to stressors. Breath!

https://pubmed.ncbi.nlm.nih.gov/24380741/