But I know a base jumper .. and he only does the jumps if he feels the fear and his kick is to overcome it and feel the adrenalin rush.
This sentence has beautifully crystallised the meaning of what it means to be an adrenalin junkie ^_^
I can identify with this “adrenaline junkie” definition, with qualifications. It’s probably different for everyone, but for me it’s more about “playing the edge”. I’ve crashed badly in the past going over that edge, but my-oh-my is it beautiful to approach, and get as close as you can, and look into the abyss for a moment. When the fear becomes too much, you back off. Over time (and survivorship bias!) you grow to have an immense respect for that edge.
Now, when I (rarely) go past the edge, I’m not flying past it to my death, my approach was appropriately calculated to produce a recoverable step-down or at worst a minor side-fall. I haven’t gone over the handlebars in years.
EDIT: People are a complex blends of emotions and motivations, so you're certainly right that can be another explanation for the same observable behavior. I really liked the comment about adrenaline junkies too. My point was only that on average it's low-sensitivity people who engage in those sorts of activities. Scaredy cats like myself stay home and read a good book.
Looking into this more, studies have found that we tend to rate the possible loss of $100 twice as painfully as the pleasure from the possible gain of $100. This can lead to irrational behaviors.
Increasing the weight we give to potential rewards is not necessarily a bad thing.
I think this can help explain the "calming of the nerves" that slow breathing promotes. If you need to speak in public and your heart is racing and you're shaking, this is an irrational reaction to what ought to be a very safe situation. By focusing more on the rewards (the acclaim for a good speech or whatever) and less on the imagined risks, you can calm down and speak naturally.
... and then just ran with "yay, slow breathing!! Transformative, amirite??"
And sure, "transformative" is not technically incorrect. But the linguistic implications of that word are almost always positive/beneficial, whereas in this case the transformation is overwhelmingly negative.
At best, the manuscript's language is sloppy; at worst, it's misleading. Very odd. The finding that this technique is actually bad in most cases (every situation where additional risk-taking behaviour is bad) is so interesting. Odd that they almost try to cover it up.