On 17 Sep 2001, at 11:12, Carl G. Heinzl wrote:

> > > Mike Wallace wrote:
> > >
> > > > What I can tell
> > > > you is that for myself, I have much less fatigue over multiple
> > > > dives when using a gas that is not as rich in Nitrogen. For me
> > > > there is a significant difference. Another thing that I have
> > > > found is that I must be WELL hydrated also. Slight dehydration
> > > > seems to offset the positive effects of lowered nitrogen in my
> > > > breathing gas.
> > > I, on the other hand, haven't felt much difference at all.
>
> There are LOTS of other factors to be considered.  First,
> who does multiple dives on a VERY regular basis?

Agreed but not something that I'm overly concerned with either. I
related to Don and Lee what *my* body tells *me* after repeated
dives.



It's natural
> to be tired afterward and yes, some dives are just plain
> more strenuous than others.  And by dive, I don't just mean the
> dive itself, I mean the whole preparation up to the dive including
> getting up early that morning, loading your gear, driving to wherever
> you're going, the boat ride, etc. etc. etc.  Then there's the whole
> ritual after the dive.

Agreed, but I can still tell a difference in the way *I* feel after a
particular dive using air vs nitrox regardless of how strenuous the
dive might be. In other words, for me there is a noticable difference
in the way I feel after a dive using air vs. nitrox. Obviously not
everyone feels a difference.


>
> I attend and teach several martial arts classes per week.  Even
> doing so it doesn't mean that I'm not tired afterward and
> after SOME classes I'm far more tired than others.

Yeah, but are you breathing air or nitrox or some other mixture? :-)


>
> I have noticed that if I'm working out on a regular basis and
> go diving that I am far LESS tired than if I go diving during
> a period in which my physical activity is lower.  I attribute this
> simply to being in better physical shape in many ways.

Agreed... actually resisted the temptation to whup out a duh.. :-)


>
> > I have been told this by others also.
> >
> > Then
> > > again, I'm rarely particularly fatigued after a dive regardless of
> > > the gas used.
> >
> > I am rarely fatigued after *a* dive either. It's multiples that tend
> > to fatigue me if I do not plan for them by being well hydrated and
> > using as little nitrogen as possible.
>
> Hydration certainly is a big factor and it's understood WHY it is. For
> a diver to undertake a dive without being well hydrated and complain
> about it later is a bit like hitting yourself in the head with a
> hammer and not stopping when it hurts.

Yep.


>
> > This might be for one of several reasons: 1. I don't work
> > > particularly hard during most dives.  I'm a cruiser, not a
> > > sprinter.
> >
> > Me too.
>
> When I'm taking video I sometimes find myself swimming after sealife.
> For anyone who has tried this you know how hard it can be... but, it
> allowed me to capture a turtle for 8:30 while he was just cruising
> around (against the current nonetheless).  Swimming after the turtle
> is bad enough, but keeping an eye on the video is even more work :^)

This is one reason why I prefer to go with the flow as much as
possible rather than fight it. I'm out there for enjoyment. When it
gets too much like work then I bail.


>
> > > I suspect that exertion during a dive is as much and maybe more
> > > important to post dive fatigue than the gas used.
> >
> > Possibly. I'm sure it has an impact on it.
>
> I don't believe the gas will matter much unless you're starting to
> talk about a "deep" dive - say approaching 100' or more.  The reason
> is that nitrogen loading at the shallower dives plays a progressively
> smaller part.

How so? The greatest change in pressure is in the shallow parts and
the fast tissues are loading up big time here.


>
> > 2. I use nitrox to
> > > extend the dive rather than decrease DCS risk for a dive of the
> > > same length.
> >
> > Me too. Many of my dives reguire deco stops so my use of Nitrox is
> > generally aimed at reducing deco times rather than avoidance of DCS.
> > Although I guess you could say that deco and DCS avoidance attemps
> > is one and the same. :-)
>
> I would agree with that!!!
>
> > If nitrogen in the system is, in fact, indicated by post dive
> > > fatigue, I may be getting the same or similar effect from a same
> > > or similar load of nitrogen.
> >
> > Nitrogen in the system is a given after every dive.
>
> > 3. I may not be hydrated particularly well.
> > > While I try to avoid being dehydrated, I don't do anything in
> > > particular to ensure I'm well hydrated either . . . and I do drink
> > > caffinated beverages.
> >
> > I drink the caffine also. I just try to drink a lot of water just
> > before a dive also.
> >
> > 4. I may just be lucky.
> >
> > Ya spins the wheel, ya takes your chances! :-)
>
> I'd rather put some weights on the wheel to bias my chances
> a bit in my favor :^) :^) :^)

Isn't that what Nitrox is all about?  :-)


>
> Carl
>


~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mike Wallace
Wilson Lumber Company, Inc.
256.852.7411 x225
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