Six Breaths Per Minute

I was surprised the first time I heard that the optimal number of breaths per minute for a human is about six. 

Try it: sit down somewhere comfortable and try to take six breaths (in and out is one breath). Make each one last about 10 seconds. No need to time it perfectly. 

When I first tried this activity, I pictured my breath going up a flight of stairs and back down. Or perhaps taking an elevator to the top floor, and then back down to the basement. 

Not a journey, but exercise for the mind.