Benefit of Nitrox?

[MaxBottomtime]

Millions of parents tell their children about Santa Claus and the Easter Bunny.

 

[Lorenzoid]

. . .
I find it interesting that I read all the time about this statement of " there are no studies or proof that Nitrox makes anyone feel better ". At what point does the huge number of people who claim they feel better become evidence that indeed it does make you less fatigued or "better"? . . .

Never. 2000 anecdotes are still anecdotes.

 

[Bob DBF]

I agree. The problem with any study that compares air to Nitrox and its effects on post-dive fatigue is that physiological effects, i.e., bubbles, immune reactions, enzymes, etc. can be measured while fatigue is subjective. My post-dive fatigue may be someone else's tired.

Actually, the studies mentioned earlier in the thread don't seem to have a problem measuring fatigue, however feeling better does not count as fatigue in the studies. The second study came up with two interesting events, but since they were not a part of what they were studying, they are just an aside in the study. The first was that the subjects could not determine the gas they were breathing, even though some were sure they could. The second was on one of the post dive tests, the results showed that subjects consistently felt better after diving with Nitrox. The authors commented that it could be due the stress of off gassing or some other mechanism, but not from fatigue.

My point is that the studies have a very limited definition of fatigue, and what you and I may say is fatigue would have a much broader meaning than what they were studying. In other words, the study showed that Nitrox did not lower fatigue, but there was an indication that the subjects felt better after using Nitrox. Which is what a lot of divers have been saying in less scientific terms.



Bob

 

[DevonDiver]

The authors commented that it could be due the stress of off gassing or some other mechanism, but not from fatigue.

Which makes perfect sense... as I think many would expect a hyperbaric root cause from using hyperbaric oxygen/nitrox on dives.

Nitrox reduces decompression stress.... a known and studied factor. Other issues do also, including dive profile, repetitive dives, multi-day dives, ascent speeds and stop strategy.

Where divers don't have a refined ascent speed or stop strategy, then nitrox use remains a factor in decreasing decompression stress. If decompression stress is a 'norm' for the diver, then nitrox makes them feel 'better'.

Recreational divers seem to refuse to believe that they can subject themselves to severe decompression stress.... but it's the fast-tissue parameters that often dictate that. Fast-tissue off-gassing is as much a factor for recreational divers as it is for technical divers.

A high level of decompression stress is thought to present as per 'non-clinical' DCS. That's just drawing a line on symptom severity. It's accepting a sub-optimal physical state after diving. Denial?

Actually, the studies mentioned earlier in the thread don't seem to have a problem measuring fatigue, however feeling better does not count as fatigue in the studies. .....

My point is that the studies have a very limited definition of fatigue, and what you and I may say is fatigue would have a much broader meaning than what they were studying. In other words, the study showed that Nitrox did not lower fatigue,....

As you say, the study was 'NITROX Vs FATIGUE'. With very strict definitions on measurable fatigue.

The study wasn't 'NITROX Vs DECOMPRESSION STRESS'. Where decompression stress was measured through bubble score.

Neither was it "DECOMPRESSION STRESS Vs SUB-CLINICAL DCS SYMPTOMS'. Where sub-clinical decompression symptoms were measured through subjective participant wellness and vitality on a scale.

 

[AfterDark]

So all these years I've been fining around in the shallows post dive to use up a little more air before a refill has been just the right thing to do relative to DCS stress! I was doing SS before the words was used in diving. What a lucky lad I've been all these years!

 

[DevonDiver]

So all these years I've been fining around in the shallows post dive to use up a little more air before a refill has been just the right thing to do relative to DCS stress! I was doing SS before the words was used in diving. What a lucky lad I've been all these years!

....and, as a result, you probably never, or rarely, "felt better" (less worse) when you've used nitrox

 

[Searcaigh]

Last July I visited North Sulawesi and dived exclusively Nitrox for 14 days diving, mainly EAN32 except for the EAN28 I used for a 40M dive on a wreck with another buddy.

Normal day started at 0630 and generally I was in bed not later than 2200, in fact some days by 2100, we were doing between 2 to 4 dives daily.

Slept sound every night as I usually do after a days diving, if there was ever a placebo effect of Nitrox, then it has long worn off with me, although I was never knackered since all my kit was carried on to and off the boat by other people except my camera housings.

Post diving a lot of time is taken up by downloading images, making sure batteries are all charged for the next dive etc., that seems to exhaust me a lot more mentally rather than physically as I was also taking care of the camera that my daughter was using.

 

[halocline]

I haven't read this entire thread, so I might be repeating someone, but for anyone who experiences "feeling better" after diving with nitrox vs air, try doing the same profile on air but with an additional 5-10 minute stop at 10ft, depending on the aggressiveness of the profile. Closer to NDL and higher loading, longer stop. Follow that with a full 1 minute ascent from 10 ft to the surface. I suspect that most divers will experience a very similar loss of fatigue that they do when diving recreationally with nitrox. This has really worked for me, and certainly supports the sub clinical DCS/decompression stress argument.

If you're not interested in spending some extra minutes at 10 ft, spend the money on nitrox. If I can save $30-40/day by enjoying life at 10ft for a bit of extra time, I'm all in.

 

[AfterDark]

....and, as a result, you probably never, or rarely, "felt better" (less worse) when you've used nitrox

That's a fact never felt any different with or without nitrox. Gezzer gas my a$$.

 

[boulderjohn]

I have for a number of years had a question that I hope someone with better medical knowledge than I have can explain for me.

When a friend of mine got bent and had to go through a serious of hyperbaric treatments, he was never alone in the chamber. Others were getting treatments as well, but none of them were being treated for anything related to diving. In fact, many hospitals with hyperbaric chambers will not treat DCS victims, reserving their use for patients with a wide variety of other ailments. When he played with the Denver Broncos, linebacker Bill Romanowski owned his own chamber and used it to speed recovery after every game. Here are some highly reputable medical web sites describing the benefits to the healing body of hyperbaric oxygen therapy:

Hyperbaric oxygen therapy - Mayo Clinic
https://www.nlm.nih.gov/medlineplus/ency/article/002375.htm
Medscape: Medscape Access
Hyperbaric Oxygen Therapy for Wound Healing | Johns Hopkins Medicine Health Library

So here's the question: why does inhaling elevated oxygen under pressure have such well proven benefits to the body when done in a hyperbaric chamber, yet it has no such effect when done under water?