Yes, “Slowing down the exhalation is considered the most direct way to balance the vagus nerve”… See Dr. Schwartz’ site.

https://drarielleschwartz.com/the-vagus-nerve-and-your-health-dr-arielle-schwartz/#.X40izy0ZPjF

… yet has some interesting points about eastern Taoist connections and western athleticism as well – here, as a break from therapy, therapy!

“The wise man breathing from his heels says that if you breathe in and out of your feet, in that process you will have a sense of your breath going from your feet all the way through your entire body to the top of your head and out your fingertips.”