What This Timer Is Doing
The one rate with a physical reason behind it
Five and a half seconds in, five and a half out, no holds. Eleven seconds a cycle, about 5.5 breaths a minute — which is roughly where the adult cardiovascular system resonates. At that rate the rhythm of your breathing and the rhythm of your baroreflex line up, heart rate variability reaches its largest amplitude, and the effect is big enough to watch happen on any HRV monitor inside a minute.
This is the best supported pattern on the site. It is the rate that heart rate variability biofeedback protocols train toward, and meta-analyses of those protocols find moderate reductions in anxiety and depressive symptoms. Your own resonance frequency is probably somewhere between 4.5 and 6.5 breaths a minute; 5.5 is the population average rather than a number you have to hit exactly.
It is also the least dramatic of these to do. Nothing to hold, nothing to count beyond following the dot. That is why twenty cycles is the default — the effect builds over minutes, and a thirty-second attempt will not show you anything.
Questions
Why 5.5 and not 6?
Both sit inside the resonance band and either will work. 5.5 is marginally closer to the population mean. The more useful experiment is to try 6-0-6-0 and 5-0-5-0 as well and keep whichever you can hold for five minutes without effort — that is a better guide to your own resonance frequency than the average is.
Do I need an HRV monitor?
No. A monitor is useful for finding your personal resonance frequency and for seeing that something is happening, which some people find motivating. The breathing works the same either way.
Is this the same as box breathing?
No. No holds, and a slower rate. Box breathing is built for an acute moment — something to do in the two minutes before you walk into a room. Coherent breathing is built for a sustained daily practice, and it is the one to pick if you are only going to keep up one of them.