I haven't tried the one nostril approach except briefly in yoga class, but you can control your energetic/restful activation level by controlling the length of

I haven't tried the one nostril approach except briefly in yoga class, but you can control your energetic/restful activation level by controlling the length of inhalation and exhalation. https://www.psychologytoday.com/us/blog/the-athletes-way/201905/longer-exhalations-are-easy-way-hack-your-vagus-nerve https://www.psychologytoday.com/us/blog/the-athletes-way/201... "Box breathing" https://quietkit.com/box-breathing/ https://quietkit.com/box-breathing/