The fast forceful practices are not for everyone. With high blood pressure, heart trouble or glaucoma, leave them out and use the slow ones, which carry no such warning.
Rapid breathing with effort behind it raises pressure inside the chest, the head and the eyes for as long as you keep it going. The gentler lift, hands and arms and a fuller breath, gets you somewhere similar without any of that. If you are teaching, say the cautions before the practice rather than after, so nobody has to interrupt to ask.
Qur’an and Sunnah
He gave you hearing, sight, and minds (Quran 32:9). These came as gifts rather than earnings, and looking after them comes before any practice that might strain them.
ثُمَّ سَوَّىٰهُ وَنَفَخَ فِيهِ مِن رُّوحِهِۦۖ وَجَعَلَ لَكُمُ ٱلسَّمۡعَ وَٱلۡأَبۡصَٰرَ وَٱلۡأَفۡـِٔدَةَۚ قَلِيلࣰ ا مَّا تَشۡكُرُونَ
Then He moulded him; He breathed from His Spirit into him; He gave you hearing, sight, and minds. How seldom you are grateful
Qur’an 32:9read it in the library
Translation: M.A.S. Abdel Haleem, The Qur'an, Oxford University Press, 2004.
What the research says
What has actually been tested is the slow end. In young adults with prehypertension, heart rate variability biofeedback lowered blood pressure and improved baroreflex sensitivity, so slow breathing has some evidence behind it for the very conditions that make rapid breathing unwise. Nobody has run the equivalent trial on forceful rapid breathing, which is precisely why the caution stands rather than being lifted.
Lin G, Xiang Q, Fu X, Wang S, Wang S, Chen S, Shao L, Zhao Y, Wang T. (2012). Heart rate variability biofeedback decreases blood pressure in prehypertensive subjects by improving autonomic function and baroreflex.. Journal of alternative and complementary medicine (New York, N.Y.) doi
Strength of evidence: one line of research. A single study, or a theoretical account.
Why it works
Forcing the breath quickly raises pressure inside the body, which matters when some part of you is already under pressure.
This one is still a draft. It is waiting on a scholar and a clinician to read it before it is published.
Near this one
Any breathing instruction that reaches you through a screen or a book comes from someone who cannot see you. Keep the final say over what your body does.
If you keep only one thing, make the out breath longer than the in breath. Four in and eight out is enough, and nothing clever is needed on top of it.
For when you are stuck in shutdown there is a faster practice: short sharp exhales driven from the belly, letting each in breath happen by itself, about twenty of them.