That life sustaining substanence ...

[BillP]

Sounds like a good rule of thumb, Mario. But again, if you've had a significant amount of caffeine you'll urinate more, more often, and clearer than if you hadn't had caffeine and that gauge will be less reliable as an indicator of hydration.

 

[Walter]

Excess B vitamins are expellled in the urine and the turn your urine yellow. If your urine is clear, chances are you are shorting yourself of B vitamins.

WWW™

 

[John Reinertson]

Most of the yellow color in normal urine is not B vitamins but urochrome and flavonoids.
B vitamins will indeed color urine yellow, but if you drink enough water, you can really dilute your urine and make even vitamin loaded urine pretty pale.

Diving medicine courses often emphasize the clear urine rule, but pale yellow is probably just as good.

Coffee in moderation is probably no big deal.. just drink water along with it.

John Reinertson

 

[TKD_DIVER]

I used to be a huge coffee drinker and have stopped altogether now for 1 year. General health is much better and I don't get nasty headachs anymore, especially if I did'nt have at least a cup by 9:00. I now drink decaf green or decaf herbal teas - not the same but they provide some psychological crutch. Anyway I digress


Forms of water loss. As the Docs mentioned include

Breathing dry compressed gas. Over the course of a 1 hour dive this add up to quite a significant amount of water. Consider the following: Exhale against a piece of cold glass and see just how much moisture is left there. Remember this is at an average ambient humidity of between 30-70%. Now think how much more moisture that can be imparted to the air by your body when the ambient moisture content is near 0% Also - as BillP points out - multi day diving takes a big toll here as does flying since the cockpit air is also essentially zero humidity.

Evaporation. Even if you don't feel wet and sweaty you are still perspiring. It just happens to be at a rate that is less than the rate of the sweat's evaporation into the atmosphere (or surrounding water) so you may not even notice it. When your exertion level goes up the perspiration rate increases until it is greater than the evap rate and BAM- you are a sweaty mess. This can also be quite considerable especially if it is a strenuous dive, or if it is hot.

Peeing nuff said already

So even without artificially increasing your water output you will still lose a significant amount of water.

I would drink it in moderation, its not horrible, but adds another factor to consider. Plus if you're in a drysuit and you gotta go its alot messier than in a wetsuit (and noone pees in their wetsuit - right???)

Bill

 

[Dr Deco]

Dear Readers:

[sp] In NASA studies involving elevated temperatures, such as individuals in a Launch and Reentry Suit (the familiar orange suits you see the crew wearing at liftoff), we always measure the loss of water from breathing and sweating. This is termed insensible water loss by physiologists and can be considerable. Some aspects of this apply to divers.

[sp]Along with the change in blood flow to the periphery of the body to maintain temperature balance, these flow and fluid changes can lead to physiological changes. In the case of the astronauts, it is problems with balance when standing. With a diver, it would manifest itself as changes in gas washout during the surface interval.

Dr Deco

 

[gozumutti]

As the ultimate morning monster, I am often tempted to take my espresso intravenously......and Dr. Jon, I insist that you CANNOT get espresso in France, at least not drinkable, with the exception of my house. I make real Italian espresso, not that ersatz stuff the French call café...

I HAVE heard that filter coffee is worse than espresso, because the water sits in the grounds for a longer period time, and the grounds therefore diffundate more bitter and toxic substances into the water...Does anyone know if this is true?

Dr. Deco, I know this is a stupid question, but doesn't natural thirst cover dehydration? Don't people simply get thirsty if their liquids drop below a certain level?

p.s. is "diffundate" a word or did I just make that up...

gozumutti

 

[TKD_DIVER]

By the time you 'Feel' thirsty you are already substantially dehydrated




Bill

 

[Dr Deco]

Dear gozumutti:

It is true, that you are substantially under hydrated by the time you finally feel thirsty…


Dr Deco

 

[gozumutti]

hm, I never realised that...thanks for the reply, I have just learned something new!

 

[turnerjd]

Originally posted by gozumutti
As the ultimate morning monster, I am often tempted to take my espresso intravenously......and Dr. Jon, I insist that you CANNOT get espresso in France, at least not drinkable, with the exception of my house. I make real Italian espresso, not that ersatz stuff the French call café...

gozumutti

Gozu,

I'm rapidly coming to this conclusion myself. I have been singularly unable to find anything like decent coffee here. Last w/end I was in central lyon looking for a propper specialist coffee shop in the hope of getting some fresh ground decent coffee for my filter machine, and also some properly ground expresso, and I didn't find anything.

The stuff I have found in the hypermarché (even their most expensive) leaves a lot to be desired.

Is your expresso one of those proper italian top of the stove machines, or a High pressure steam one? I have both, but the stove top one makes expresso that knocks your socks off!

I thought you were in the land of watches and cuckoo clocks, the above sounds like you have connections in this part of the world as well?

Jon T