Thanks for posting, Henry! It's always great to see you.
The first clue that this isn't worth much is the horrible grammar.
The science isn't any better. It reminds me of how I was trying to impress a Greek friend by using a translator to send a short note to her in Greek. Her English was excellent. She wrote back that she could understand what I was trying to say, but it really wasn't coming out right. And so is the case with this individual. This is "junk science" at best. It's painful to read.
Our bodies are pretty resilient to doing all sorts of unusual breathing. As long as we don't Valsalva (hold the breath and bear down), the body pretty much self-regulates. The kinds of changes from deep breathing that they're talking about in this article are dwarfed by the kinds of changes that occur in an athlete's body (such as when I was running cross country) with normal, healthy athletic exertion.
No, bad things won't happen if you hyperventilate a bit. You'll get your blood gasses out of whack for a bit, and it will cause some general physiologic changes. And then when you stop, you'll go right back to normal. After a while, any moron will self-regulate.
The breathing methods used by various Yoga practitioners or taught by myriad sports trainers (e.g. Scott Sonnon) are just attempts to optimize our respiratory system for certain specific applications. It is what it is. A little exploration into yoga, power breathing, Goju Sanchin breathing, or traditional Uechi Sanchin breathing is all wonderful stuff. And again... do these various patterns long enough and you figure out what works.
Concerning a picture in this article allegedly having something to do with deep breathing...
What unhealthy people (e.g. those with critical stenoses in coronary arteries) do is another ball of wax. Nobody should be stressing their body if they're a snow shovel scoop away from angina. They should be seeking medical attention, and not the advice of some half-baked online yoga "expert." Trust me... I spent 4 years creating heart attacks in the academic cardiology lab. I lost more than a couple of experimental preps in my years there; it's not kid's stuff, or the domain of amateurs. Our work got published because it's literally a matter of life and death.