Interestingly enough, I entered a friend’s clinical research study last year where they’re looking to replace the standard cardiac stress test by proving their hypothesis.
Essentially, they believe that by purposefully engaging in a combination of deep/long/shallow/etc. ("Wim Hoff style breathing techniques" - my friend’s words not mine), and get a patient to hyperventilate basically (in a controlled environment and developed protocol/framework), they could produce similar results and draw similar clinical conclusions as one would after a traditional stress test. They had me do two hours of various breathing techniques while simultaneously imaging my heart and then my brain using fMRI imaging.
* NAD but I managed to get the DICOM files and found some open source software (Horos) and loaded up the slices and it was super cool seeing what was going on during the different breathing *
I recently caught up with the individual and was told the study is in its final stages and so far looks very promising (which I’m sure all researchers say right but I’ll give them the benefit of the doubt).