Why Nitrox

[Walter]

I think Walter and others would agree that micobubbles contribute to the feeling of fatigue we sometimes feel after a dive.

Possibly in rare cases, but in general, no. Fatigue is not a common symptom of DCS. There's no reason to believe it is a common sympton of subclinical DCS.

Asserting the world is flat does not make it so. If you want to convince me nitrox makes people feel better, show me a double blind study that backs that concept. I only know of one study so far and it shows no difference between air and nitrox in fatigue or good feelings.

 

[Goose75]

...I believe you feel better because you want to feel better so badly that your body obeys and you do. Same reason people can firewalk, go into a trance, etc. It's your mind controlling the body and that's all, IMO.

Hhmm. I believed the same as you. I figured that the whole feeling better aspect worked because you decided to believe it. When I started diving Nitrox for the bottom time, my headaches and fatigue after repetitive dives were non-existent. At first I denied it. I figured it was just my imagination. Unfortunately this unnatural state of good feeling persists.

My rational mind wants to believe that I'm a dirty liar and that I have been a secret believer all along. I've decided to refuse to believe that I feel better and see if that stops it.

 

[Walter]

If you feel better, you feel better. We are not disputing some people feel better after diving with nitrox than after diving with air. We are merely discussing the reasons you feel better. Evidence suggests it is psychological, but even if it is psychological, you still feel better.

 

[MildlyDamp]

I haven't seen any mention in this thread of how the increased bottom time offered by nitrox is affected by the particular dive computer you're using. I have a Suunto Cobra, which is extremely conservative, and I've found myself hitting the no deco limit on repetitive dives more than once with it. Anyone who is relatively good on their air consumption probably has the same experience with this computer. I use nitrox when it's appropriate to extend my bottom time.

However, if I was using a less conservative computer (namely, anything else!), I might find that I would run out of air before decoing out. Nitrox would probably be less useful in this case, unless you're talking about 3+ dives per day.

 

[DandyDon]

If you feel better, you feel better. We are not disputing some people feel better after diving with nitrox than after diving with air. We are merely discussing the reasons you feel better. Evidence suggests it is psychological, but even if it is psychological, you still feel better.

Reminds me of a story a drug rehab counselor told me once: Dealing with addicts on withdrawal, he gave them sugar pills warning them that they were very potent. Some of the addicts said it was the best high they'd ever had.

:lol:​

 

[Footslogger]

However, if I was using a less conservative computer (namely, anything else!), I might find that I would run out of air before decoing out. Nitrox would probably be less useful in this case, unless you're talking about 3+ dives per day.

======================================
Most of our diving is on liveaboards and 3 - 4 dives/day so that is exactly why we use Nitrox.

'Slogger

 

[espenskogen]

Shooting to the surface is NOT within the NDL limits by any tables I am aware of. I certainly hope you are not actually advising someone to do anything as dangerous as this
All tables are designed to operate within a certain ascent rate. The PADI tables for instance are designed to work with 60ft/min of ascent. If you ascend faster than that you are outside the limits of the tables and the results could be very serios.

No, of course, I'm not suggesting doing a missile ascent. I'm merely saying that should you do an ascent not atypical for a recently certified openwater diver, you are breaking the NDL recommendations on the tables, and that would make you feel fatigued. If you try to simulate an ascent like this, you will feel the fatigue we're discussing here.

 

[espenskogen]

Although I have never read any studies on the subject until now I have always believed that nitrox allows you to feel better after a dive in the same way that deep stops and very slow ascents from the last 20ft make me feel better than just following NDL limits of outdated tables
It all depends how you use it

Absolutely agree with you. There are no studies that conclusively proves that deep stops reduces subclinical DCS, nor are there any studies proving deep stops making you feel better. There is however a hell of a lot of divers who swear by deep stops on deco dives for exactly this reason. I think the same argument applies to nitrox. You cannot prove that nitrox makes you feel better, because you can't prove a feeling.

You can however prove that reduced nitrogen load reduces the chance of subclinical dcs. And you can prove that not having dcs makes you feel better than having it.

This is an academic discussion anyway - We all agree that nitrox is the next best thing since sliced bread, so why don't we just leave it at that.

E

 

[espenskogen]

If you feel better, you feel better. We are not disputing some people feel better after diving with nitrox than after diving with air. We are merely discussing the reasons you feel better. Evidence suggests it is psychological, but even if it is psychological, you still feel better.

I haven't seen any evidence suggesting it's psychological. I've just not seen evidence proving a feeling. We know nitrox reduces the nitrogen load and hence reduces dcs risk. What we're really discussing is at what point does dcs make you feel ill. And since we can't conclusively prove a feeling, it's a bit of a difficult one. I recon if we do a test with a doppler examination after an air dive and a nitrox dive with the same profile, we'll see that if the air diver is having microbubbles, he might not feel like going for a jog. But I expect a dive doc would probably be the person to settle this discussion - Maybe ask doctor deco to give some input into this.

E

 

[espenskogen]

I haven't seen any mention in this thread of how the increased bottom time offered by nitrox is affected by the particular dive computer you're using. I have a Suunto Cobra, which is extremely conservative, and I've found myself hitting the no deco limit on repetitive dives more than once with it. Anyone who is relatively good on their air consumption probably has the same experience with this computer. I use nitrox when it's appropriate to extend my bottom time.

However, if I was using a less conservative computer (namely, anything else!), I might find that I would run out of air before decoing out. Nitrox would probably be less useful in this case, unless you're talking about 3+ dives per day.

What your dive computer tells you is irellevant - If you get DCS it doesn't matter if the computer tells you you're okay. A conservative computer just reduces the chance - And a less conservative one increases the chance of getting hit. Nitrox reduces the chance - No matter which computer you're using.