NITROX for any and all dives?

[Storker]

+2

If I do two fairly shallow dives in a day, I usually don't feel more tired than what should be expected by the physical activity involved. If I do two deep-ish dives close to the NDL I more often than not want to be in my bunk by 8 o'clock. While I haven't done systematic double-blind studies, I have a clear impression that backing off from the NDL, either by limiting my depth and or bottom time, or by reducing the N2 content in my gas, makes me less tired. And, BTW, ascending r-e-a-l-l-y slow from the safety stop also helps.

As @kelemvor said:

"I know it's supposed to be placebo effect, but I don't care."

 

[bladder]

Sorry, I do feel less tired when using Nitrox. The issue is still anecdotal; the available studies are conflicting, inadequate, and off target. Someday the science may actually get done and be compelling. Until then, and perhaps after then, I will feel less tired when using Nitrox.

No need to apologize, there's no doubt that you feel less tired, just like people who are given a placebo in controlled clinical studies show improvement.

It's unclear why, but when we believe something is going to make us feel better, it often does.

 

[CT-Rich]

I'm glad to see that there was not a single post advocating the questionable and unproven use of Nitrox over 21% because it supposedly "gives the diver more energy" or "makes him or her feel better".

...and gives a shinier coat.

I just was in Grand Cayman using nitrox. EAN 32 was included in the trip price, so I took advantage of it (I was also fresh off the training). TBH, it was nice to see the computer telling me I was four miles from the NDL, but about half the dives were not deep enough to change anything.

I think when you sell hammers, most problems are going to be described as nails. I think from the business end, touting the miracle benefits makes sense, and I can see why charters and resorts prefer it. Stopping the .1% from getting bent is going to make everyone happy. For a single diver doing a couple of tanks a weekend, it won’t make difference unless your plan is for 60’+ and you have a low SAC.

 

[tomfcrist]

Nitrox....

 

[Kimela]

I've been told that diving nitrox will lessen the dry mouth you get when diving on air. I haven't noticed a difference. I've used nitrox when doing 4 dives a day. But otherwise it's not worth the additional cost for me.

$10 per tank seems to be what I've seen most often for nitrox. The LOB we did charged $100 extra for the week (5 days of diving) and that seemed palatable. I think there's some money to be made there for those who are willing to put together packages or lower their prices/tank - but maybe it's not worth the additional effort and cost of supplies?

 

[Bob DBF]

I'll have to wing this one on memory as this tablet is a pos in finding information. When I find it I'll repost a link, which I should have done the last time.

The study, which was after the chamber study, I saw, found there was no decrease in fatigue, however they noticed that divers on Nitrox consistently felt better after the dive. The study attributed the feeling better to having less sub clinical DCS. Since the study was about fatigue the feeling better after the dive was just note on the findings.

It seems fatigue has a different scientific meaning than the meaning regular people use.

The study was double blind with the divers in the water diving. I believe there were two tank dives every other day.



Bob

 

[kelemvor]

I've been told that diving nitrox will lessen the dry mouth you get when diving on air.

This is the first time I've heard that. Do you know anything about how it's supposed to be a factor?

 

[Lorenzoid]

All things being equal (ie cost), I would use Nitrox on every dive. Why? The reduced nitrogen uptake for a given dive duration.

That's my thinking. In a nutshell: More nitrogen cannot be better for me than less nitrogen. I haven't noticed any effect on fatigue during those multiple days of multiple dives, but then again, I can't say I have done a comparison with the exact same sequence of dives on air.

Still, when some smartarse huffs "Air is for tires," I want to smack them.

 

[Steve_C]

I dive Nitrox all the time. After a dive I get my tanks filled. I never know where the next dive will be. They are several days apart. Might be a quarry. Might be on an offshore ledge at 100 ft. There is always a hard bottom under me at 120 ft or less where I dive. I dive HP100s. Most Dives are NDL limited especially second dives. The cost is not a factor. So I always get Nitrox 32%.

 

[Storker]

I've been told that diving nitrox will lessen the dry mouth you get when diving on air.

How would that work?

Regarding post-dive lethargy and tiredness, there's a plausible hypothesis: Excessive bubbling below the level that leads to proper bends may lead to sub-clinical DCS, which may manifest as lethargy and tiredness. The closer you are to the NDL, the greater the risk that you'll have a lot of microbubbles in your blood and tissues. And the greater the risk that you'll experience symptoms of sub-clinical DCS. Now, since proper, peer-reviewed research has shown that the amount of post-dive bubbling varies a lot between individuals, it's no surprise that some divers experience an improvement when they use nitrox while others don't.

When it comes to dry mouth issues (or gas consumption, which is another topic where I've been told that nitrox has a beneficial effect), I'd like a cite for WHY nitrox makes it better before I start believing it.

EDIT: And just FTR, what I'm talking about isn't avoiding normal tiredness, or feeling particularly energized after breathing nitrox. What I'm talking about is that excessive tiredness, lethargy and sleepiness that quite a few divers - me included - experience when they've been close to the NDL and/or haven't made sure that they perform a proper safety stop and avoid corking from their safety stop.