Any sound suggests that some air passes the larynx, which means it isn't in complete spasm. But it may not be open enough to permit air to pass readily as it expands with ascent.
Nitrox discussion (Split from "Reasons not to use Enriched air" thread in Basic)
- Thread starter orch1ds
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InTheDrink
Contributor
That is correct. Nothing scientific about it because it's all in your head. (yes, pun intended)
To add to the OP's question...Reasons not to use nitrox include thinking that..."it will make me less tired, it doesn't give me headaches, and it makes me safer." The first two are placebo.
Can you point me towards some info on this placebo effect? I'm not saying I don't believe you, just I'm surprised as I didn't come up with the 'lack of headaches and less tiredness' after speaking to somone, I observed (or believed I did) these effects alone so would be interested in reading more on why these points are not considered true.
Anyhow, I'll continue believing on the basis that placebo can be better than nothing
ianr33
Contributor
I'm convinced that reduced fatigue and no headaches are not due to any magical properties of nitrox but rather to decompression stress using air.
Slow down the ascents,extend the safety stops and the fatigue will go away.
Slow down the ascents,extend the safety stops and the fatigue will go away.
hobodiver
Contributor
During my AOW class, we made 5 dives over 2 days using air. On the first day, I got a headache at one point and ended up taking some asprin later. After the 2nd day, I was very tired and sore, although I will attribute the soreness to being somewhat out of shape.
A few weeks later, after taking my Nitrox class, I did 5 dives at the same location (and generally the same profile) in a single day using EAN32, and had neither headaches or tiredness/soreness. Certainly anecdotal, but I wouldn't throw the theory out the window entirely.
Edit: I should add that none of the other people I was diving with did more than 3 dives.
A few weeks later, after taking my Nitrox class, I did 5 dives at the same location (and generally the same profile) in a single day using EAN32, and had neither headaches or tiredness/soreness. Certainly anecdotal, but I wouldn't throw the theory out the window entirely.
Edit: I should add that none of the other people I was diving with did more than 3 dives.
Thats pretty much my view on it.
Certainly same type of profiles nitrox vs air i notice absolutely no difference in fatigue at all after a day of diving. (i dont get headaches since i sorted out my CO2 problem unless its a really hard dive for some reason).
However on accelerated deco dives i feel fresher leaving the water (i) after doing proper deep stops and (ii) decoing on 100% not 80 or 50.
Back gas wise though i cant see any difference nitrox v air for fatigue personally.
InTheDrink
Contributor
Hmmm, I ascend fairly slowly and do a deep as well as shallow stop but I'll try even slower. I did notice that on shallower dives in the UK on air I am not getting headaches so perhaps there is something in it. Altho I have also stopped smoking immediately before a dive since diving in the UK so perhaps that helps too. As always, too many variables to make definite statements.
J
Both of that screams CO2 retention which is by far the most common cause of diving headaches. Shallow dives, breathing resistance of the reg is less, partial pressures are less so no headaches. Smoking is also a great way to retain CO and indirectly CO2 and both these under pressure can cause that.
The 1.4 / 1.6 is already a built in safety margin.
As to feeling better after nitrox... Sub-clinical DCS, that feeling of fatigue after a dive, I have read, can be due to the body acting on the increased nitrogen in the blood / tissues in a way that is similar to it fighting off the flu. Thus flu like fatigue, which is lessened by less N2 in the body.
I also feel better after doing deco on 100% verses 50% or 80%.
If this is all hogwash, please don't tell me and spoil the nice placebo effect I have working for me.
As to feeling better after nitrox... Sub-clinical DCS, that feeling of fatigue after a dive, I have read, can be due to the body acting on the increased nitrogen in the blood / tissues in a way that is similar to it fighting off the flu. Thus flu like fatigue, which is lessened by less N2 in the body.
I also feel better after doing deco on 100% verses 50% or 80%.
If this is all hogwash, please don't tell me and spoil the nice placebo effect I have working for me.
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