Hydration: decompression efficacy vs IPE/IPO

[elan]

Good hydration is unfortunately not easy measurable. Best is to drink during the day normal amounts of fluid, preferably water.

100%. I can drink 1-2 litre a day on a cold winter day doing nothing or 6l on a 10 hours biking trip in summer.

 

[Esprise Me]

It seems that urine color would be especially unreliable as an indicator of dehydration when the person has consumed diuretics such as alcohol or caffeine. My pee has never been any of the colors associated with dehydration in that chart. But if I've had a cup of coffee, wouldn't that make my pee at least a little lighter than it would be otherwise? Likewise, diving makes you pee more than you would on land; doesn't the immersion enuresis work similarly to a diuretic to lighten the color?

I've noticed lately that I sometimes come back from a day of boat diving feeling utterly wrecked. I have a number of hypotheses I'm exploring, including but not limited to sub-clinical DCS with dehydration as a possible contributing factor. I've been tracking and adjusting my water and caffeine consumption, frequency of urination, and other factors such as how much sleep I'm getting, in hopes of figuring this out. But lately I've been wondering if there's a better way to answer the question "how well-hydrated are you at this moment?"

 

[Jcp2]

It seems that urine color would be especially unreliable as an indicator of dehydration when the person has consumed diuretics such as alcohol or caffeine. My pee has never been any of the colors associated with dehydration in that chart. But if I've had a cup of coffee, wouldn't that make my pee at least a little lighter than it would be otherwise? Likewise, diving makes you pee more than you would on land; doesn't the immersion enuresis work similarly to a diuretic to lighten the color?

I've noticed lately that I sometimes come back from a day of boat diving feeling utterly wrecked. I have a number of hypotheses I'm exploring, including but not limited to sub-clinical DCS with dehydration as a possible contributing factor. I've been tracking and adjusting my water and caffeine consumption, frequency of urination, and other factors such as how much sleep I'm getting, in hopes of figuring this out. But lately I've been wondering if there's a better way to answer the question "how well-hydrated are you at this moment?”

It’s hard to say because what we think of as adequately hydrated normally is for land based upright activity with gravity passing a role. Our heart is designed to perfuse our brain as the highest point. Diving puts us in a horizontal weightless attitude, so the closest I can think of would be studies on astronauts to see if their fluid intake changes in orbit because of respacing of body fluids.

 

[Teleopsis]

I'm not an expert on diving and hydration but I have done a lot of fairly extreme endurance sport and the advice nowadays is to drink to thirst but not much beyond. Too many people dying from overhydration causing things like hyponatraemia, no good evidence of adverse effects of being a bit dry (of course severe dehydration is not good). Most of the stuff that comes out of lifestyle magazines about having to drink eight glasses of water a day is just made up and has no basis in biology.