How much easier is Nitrox 32% / EAN32% on your body?

[Sevenrider860]

your body "feels" partial pressures of inert gases. If all other dive parameters are the same, especially time, then when you use nitrox you are exposing your body to less inert gas so you should feel a bit better. How much will depend on how rich the mix is. If however you are diving to NDL on both air and say EAN32, then the total inert gas load is essentially the same and you should feel no different.

From the DAN Article...
"Given an identical dive, it is generally understood that the higher partial pressure of oxygen in nitrox — and the lower partial pressure of inert gases — will result in less decompression stress. It’s easy to make the logical leap to connect fatigue to minor decompression stress at this point, but it’s important to recognize that a higher partial pressure of oxygen also causes a different type of stress: oxidative stress. Several studies suggest the oxidative stress generated by high partial pressures of oxygen can cause mild endothelial dysfunction, which might actually lead to feelings of fatigue."

 

[happy-diver]

So when things are bad they give you o2, because it's good
when you ingest 1/3 more like any other drug it's more good

especially pushing through thick water during diving exercise

where if not for the cooling properties of water we would be
out of breath and perspiring to the max and finning nowhere

If you decide to ingest more, it's too much which is no good

Effect although imperceivable to most, must be substantial

 

[jt83]

I have found that more diving experience in general impacts how I feel more so than Nitrox. My first dive day of the season usually wears me out the most. That being said, I'm in the camp that believes (placebo or otherwise) that I do feel less fatigue after diving Nitrox.

 

[tbone1004]

@Sevenrider860 we also consider O2 to be narcotic as well, but when we are talking about recreational diving, I don't think the ppO2 is high enough to cause enough oxidative stress to offset the decompression stress. We do see it quite a bit when diving long decompression, especially if we don't do enough air breaks, but if you keep your ppO2 reasonable, I shoot for 1.0-1.2 instead of 1.4-1.6, then I certainly feel better.

 

[Addicted2H2O]

I have a question regarding Nitrox vs Air and how it makes you feel. After the first morning dive in Cozumel last Friday, I had a horrible headache (that I'd had from the night before but a little less pronounced before the dive) and I had gotten a bit motion sick floating on the surface after the dive. Bottom depth was around 80-85 FSW and dive time was roughly 45 minutes or so on air. I felt bad enough after that I opted not to make the second dive that morning, instead sitting on the boat and trying to relax as best I could with the pitching and rolling, which was fairly normal. After getting back to shore I talked to the dive operator and explained that I'd called my 2nd dive due to a serious headache (which was at that point near migraine status) and it was explained to me that I should've switched to Nitrox because the increased O2 in the mix (the average of all tanks tested was 30%) would actually help ease my headache and make me feel a bit better. It sounded like it made sense but without having tested it, I don't know if it would've worked or not. So is there any truth to that? Would diving EAN actually help with a headache due to the increased O2 content?

And to keep this on topic....I have noticed no decrease in tiredness from diving EAN vs Air over multiple dives.

 

[DeepSeaExplorer]

Nitrox pushes the NDL back, sometimes way back. So a diver that might be pushing the air NDL, switches to Nitrox and is now suddenly diving very conservatively. Less potential for decompression stress so less fatigued.

A diver that wasn’t pushing the NDL will notice no difference. This also explains why some experience Nitrox differently.

 

[AfterDark]

Nitrox pushes the NDL back, sometimes way back. So a diver that might be pushing the air NDL, switches to Nitrox and is now suddenly diving very conservatively. Less potential for decompression stress so less fatigued.

A diver that wasn’t pushing the NDL will notice no difference. This also explains why some experience Nitrox differently.

This could be a good guess. As one who has only felt an effect on my wallet using nitrox; I also never get near NDL, including using nitrox, the exception being using my 72 IDs, with 130+cuft of gas I can hit or exceed most NDL.

I also rarely make more than one dive a day. In my 20's I'd make 3 dives in a day often 6 over a weekend but that was before nitrox was available at the LDS. I would be tired, but I also wasn't rolling off the side of a boat most dives either. Often it was mountain goat diving carrying gear down then back up hills on literal goat paths. So fatigue would be expected.

 

[DeepSeaExplorer]

I tried a week of cave diving and camping once. It dropped into the low 30s at night and all I had a 3 season sleeping bag. After doing two deco dives a day in 70 degree water, even with a dry suit, I was exhausted and cold. Never again...

 

[Sevenrider860]

@Sevenrider860 we also consider O2 to be narcotic as well, but when we are talking about recreational diving, I don't think the ppO2 is high enough to cause enough oxidative stress to offset the decompression stress. We do see it quite a bit when diving long decompression, especially if we don't do enough air breaks, but if you keep your ppO2 reasonable, I shoot for 1.0-1.2 instead of 1.4-1.6, then I certainly feel better.

@tbone1004 I don't believe the article was referencing technical diving and I believe the DAN studies used recreational profiles and I think the discussion is referencing recreational profiles.

If people feel better after diving an enriched air mix...then by all means they should keep doing it. However DAN has performed objective studies on this exact topic...the "nitrox-as-fatigue-buster myth" as they call it.

Perhaps DAN's methods were incorrect or flawed or the number of subjects and demographic mix of subjects was inadequate. I can't comment about that, but they have been pretty consistent over the years on the physiological reduction of fatigue with enriched air.

"Despite divers’ frequent reports to the contrary, objective studies have not found a reliable difference in either physical fatigue or cognitive performance following dives on air compared to identical dives by the same subjects on nitrox."

 

[tursiops]

@tbone1004 I don't believe the article was referencing technical diving and I believe the DAN studies used recreational profiles and I think the discussion is referencing recreational profiles.

If people feel better after diving an enriched air mix...then by all means they should keep doing it. However DAN has performed objective studies on this exact topic...the "nitrox-as-fatigue-buster myth" as they call it.

Perhaps DAN's methods were incorrect or flawed or the number of subjects and demographic mix of subjects was inadequate. I can't comment about that, but they have been pretty consistent over the years on the physiological reduction of fatigue with enriched air.

"Despite divers’ frequent reports to the contrary, objective studies have not found a reliable difference in either physical fatigue or cognitive performance following dives on air compared to identical dives by the same subjects on nitrox."

You really should go back and look at those studies that DAN references. They are hardly compelling. As much as I like and respect DAN, it serms to me they are cherry-picking and overstating the evidence to bolster their opinion.