Random cool tattooed yogi 
First world problems, I know. What with all the world’s best doctors and scientists hard at work developing links between yoga and its effectiveness for use in treatments of REAL pathologies, it’s granted that more inspired topics are to be regulated to the backburner, and the scientific community at large can surely be forgiven for overlooking this potentially very fruitful area of research.
But such is. And we can’t all be engaged in solving life’s big problems, need some of us to engage in the little ones as well. Like ya know, dealing with tattoo pains. We all do our own part, eh?
So a quick recap on pranayama. That’s the thing you do (or try to do) during your weekly yoga classes right;
Controlled breath in. Controlled breath out. Hold for 6 counts. In… out…
Stretch out your breaths, until the thoughts ease off from your mind. Your heart slows. Your muscles relax. Time unwinds, consciousness eases, softens and fades off into the background.
Going to go catch some samadhi’s. 
In yogic practice, breath represents (or ontologically supervenes on) prana (lifeforce). Regulation of the breath entails regulation of your lifeforce. When I stretch out my breathing, I draw out my life force. As I harmonize my breathing, I clear up my vital energies, and prepare my mind-body to transition into the next stage of heightened consciousness.
Pranayama brings about pratyahara (withdrawal of the senses and an inward turn of consciousness). Pratyahara further facilitates progression towards dharana, dhyana, and the superconscious samadhi.
Now, I’d love as much as anyone to reach this samadhic enlightenment. But a dude’s still gotta navigate all the toil and toil and tribulations of samsara, ya know? Eventual self-actualization defo stays in the books, but I’ve a scheduled needling appointment soon, and I’d really like all the help I can get for that next marathon session coming up.
Pranayama and Pain Management
I think anyone who has gone for one of those hardcore Yin Yoga classes can immediately relate to the pain-management benefits of controlled breathing during a long drawn out and particularly excruciating frog, lizard or king pigeon pose. Fold deeper, keep breathing. Push deeper on each exhalation, breath into those knots and tight areas. Fold deeper. A bit more. A bit more… And then the insane bastard actually comes over and pushes you balls deep into the stretch, into that white abyss of pain. Gotta love those Yin classes.
Don’t let that smile fool you. This here is the true face of pain. 
Going to geek out a little bit here on the physio-neurological basis for the efficacy of pranayama on pain management. For those not entirely turned on by latin gobbledygook, skip straight ahead to the next pretty picture below.
For the rest of you intellectual types; regulated breathing leverages the bidirectional affect between (para-)/sympathetic state activation and directive electric signals originating from the central nervous system (“CNS”). Conscious activation of segments of the overall (para-)/sympathetic response (i.e. the slow, deep breathing part of an overall relaxed state) in turn triggers the unconscious sensory neurons transmitting parasympathetic activation back up the CNS into the brain, who then plays catch up by transmitting further motor signals down the spine out the rest of your peripheral nervous system. Upregulation of the parasympathetic (relaxed muscles, slow breathing, steady heartbeat) state opposes the rival sympathetic state activation (fight or flight; erratic heartbeats, cold sweats, jitters, pain sensitivity, tensed up muscles). By a parallel and identical process, similar activation towards the sympathetic state can be achieved through conscious exercise of rapid forceful breathing (e.g. kapalbhati), which transmits back up to the CNS, back down to the sympathetic nervous system as so.
I picked most of this from wikipedia by the way, so I know what I’m talking about.
Now there’s a good bit of research attempting to close the final leg from (para-)/sympathetic state activation and pain sensitivity. The interface between subjective mental experiences (the feeling of pain) and neuro-physiological body states has always been a bit tricky to bridge. Observed behavioral responses and subjective reporting of pain would to be sure show some difference when obtained from a sympathetically activated individual or a para-sympathetically inclined one. It’s one thing to observe behavioral responses, and another to conclude that the pain was experienced mentally, internally as more painful; am I just overreacting, or am I really feeling more pain?
Nevertheless, I’ll just throw out here the bits we wanted to hear; the experimental controlled trigger of pain and its association with activation of the sympathetic nervous system.  Pranayama and its promising use in patients with pain related pathologies. 
Tattoo Pain Chart 
But anywho, some personal n=1 experience has informed me that that long, deep breathing REALLY helps during the particularly wee sensitive bits in the ink session; Nice long slow breaths in the green. Some REALLY HEAVY DEEP BREATHS as we move on to the red. Take a 5 minute breather to help clear your mind, then that existential dread again and that moment of panic right as the needle homes into your skin…!!!!!!!…!!…haaaaaa…… Oohh yer fluffin beautie.
Granted there are probably even more niche areas for controlled breath applications out there. Like getting a covid/flu jab. Like when going for a foot massage. Or going to the dentist. Don’t know anything about those, I’m trying to write for the everyman here.
Calm mind through long slow breaths. Reversal of cause and effect. A real wonder of science, that pranayama.
– Slow, controlled breathing makes me less of a fidgety beech during tattoo sessions.
– There’s a bit of science backing the idea that pranayama can help with pain (or at least its management)
– Bit of pranayama would probably help with my spiritual side too, enlightenment and all.
Will end off with a bit of #inkspiration, because dayum, some of these pins look mighty fine.
One day, I too will be able to be like that. 
: Neuroanatomy, Parasympathetic Nervous System, Jacob Tindle; Prasanna Tadi.
: Yoga: Can It Be Integrated with Treatment of Neuropathic Pain, Telles S. · Sayal N. · Nacht C. · Chopra A. · Patel K. · Wnuk A. · Dalvi P. · Bhatia K. · Miranpuri G. · Anand A.