Dan_P
Contributor
Perhaps, but you bring it up here I suspect to sow a little more doubt about the Spisni study. It is a recurring pattern, hence my comments.
No - I'm all on board with a lower deep stop emphasis than was employed on the RD-side of the Spisni-study, mainly because of the results of the Spisni-study. I'll reiterate that I acknowledge it's findings.
I'm simply not content with a lowest-echelon learning that "deep stops, bad, shallow good" when there may well be much more to it and much more to be learnt from this study and others.
As I said, the oxygen / inflammation thing is complex. Hyperbaric oxygen is actually anti-inflammatory in several contexts, but I don't want to take the thread off topic. It can be discussed somewhere else if necessary.
Agreed, but isn't inflammation at the very core of the Spisni-study?
I would have expected a greater emphasis on bubbles measuments in the trial if that weren't the case, at least.
As the Spisni-study goes, inflammation is the main argument against (too) high emphasis on deep stops.
Yes, absolutely, when it is a deepish "rec dive" right up to the US Navy no-decompression limit and 10 minutes in excess of the DCIEM no decompression limit!
I'll ask a question here, and present my point with that question after the next quote.
If RD is 'unfavourable by evidence in human trials for showing the results it did here, doesn't it stand to reason that the Rec-dive group showing similar-ish results, would be too?
Looking at the Rec-dive group, they had a pretty heavy emphasis on shallow stops: "The maximum depth was reached after 2 min, and divers remained at 30 msw up to 25 min of dive time. The ascent was at 10m min up to a safety stop at 3 msw for 3 min and then they surfaced at an ascend rate of 3m/min."
My point is this:
Well, it was actually, though not perfectly so. I believe that was part of the reason for inclusion of the rec air dive group. Can you not see that the occurrence of a virtually identical pattern of inflammatory activation in the low oxygen air dive as the high oxygen UTD-RD dive makes it extremely unlikely that oxygen was the explanation for the inflammatory activation in the UTD-RD dive; especially since a third group with "highish" oxygen exposure (the GF dive) exhibited no inflammatory activation?
I see your logic, I understand what you're saying and I agree with that - but in turn, can you not see that the inflammation level could be high on one dive (Rec group) due to the decompression stress you mention, and on another (RD group) due to increased O2-related stress?
That's why I'm making such a fuss about it not being isolated, not because I don't understand what you're saying.
That's not to be misinterpreted as me saying the study's findings haven't appropriateness in a diver's appraisal of which deep stop emphasis to employ.
I would argue that it does.
And in saying this, you completely ignore the question. You are relentless in picking apart the evidence from human experiments that do not favour UTD-RD. Why not present the evidence from human experiments that supports it?
If you dive a computer with whichever GF you prefer, and I dive RD, and we come out actually diving the same deep stop emphasis, would you find that problematic?
I'm not relentless in picking apart evidence from human experiments, but I don't mind picking at overconfident conclusions based on that evidence, such as this example (albeit from a neighbouring thread):
"Advocating for a "strategy" that moves deco time around in a profile, rather than emphasizing more time in shallower stops on higher O2 concentrations flies in the face of the science we have. Purporting that divers are "engaging" in their deco diving because they are arbitrarily moving stops around in ways unsubstantiated by science is simply endorsing voodoo. I think it is irresponsible and a shame."
That's based on a question about what to do if subjected to hypothermia.
Just incontextual assumptions about RD being coupled with overconfidence in what one or two studies mean or even themselves claim to mean - most commonly, NEDU and Spisni.
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