OP
Dave Zimmerly
Contributor
Thanks to all for the informative posts.
Regards,
Dave (aka "Squirt")
Regards,
Dave (aka "Squirt")
So this is why I need to pee so often?
- Thread starter Dave Zimmerly
- Start date
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I had a dive instructor who taught me that, if you're wondering whether or not you've hydrated enough to jump in and dive, the rule of thumb is:
"If you're not ready to go, then you're not ready to go!"
Funny, but good advice. Between the effects described in this thread and also breathing all that super-dry compressed gas, dehydration is one of your worst physiological enemies while diving.
But it's also one of the easiest things to prevent. So drink lots of water, avoid alcohol and anything that dehydrates, and "be ready to go" warm up that wet suit right after hitting the water!
>*< Fritz
"If you're not ready to go, then you're not ready to go!"
Funny, but good advice. Between the effects described in this thread and also breathing all that super-dry compressed gas, dehydration is one of your worst physiological enemies while diving.
But it's also one of the easiest things to prevent. So drink lots of water, avoid alcohol and anything that dehydrates, and "be ready to go" warm up that wet suit right after hitting the water!
>*< Fritz
In fact, if you want to maintain good intravascular volume and reduce urine output, consuming a small amount of salt shortly before a dive will help. The body works to maintain a constant salt concentration in the blood, and if you eat salt, the body will retain water to dilute it to keep your serum sodium constant. The effect is not prolonged, but will certainly last a couple of hours. Salt should not be consumed in large quantities -- a few potato chips or saltines will do it -- and is contraindicated for people with high blood pressure which is sensitive to salt intake. (And people with congestive heart failure, although I suspect few of them dive.)
My understanding is that natural peripheral vasoconstriction due to cold shifts blood to the core. This results in a relative volume gain which tricks the body into a need to pee to compensate; the ADH mechanism explained previously. The resulting loss of water, combined with other losses (sweat, breath), does "thicken" the blood which can degrade circulatory efficiency. These effects are well-known in high-altitude mountaineering.
Inalara
Contributor
I had a dive instructor who taught me that, if you're wondering whether or not you've hydrated enough to jump in and dive, the rule of thumb is:
"If you're not ready to go, then you're not ready to go!"
Funny, but good advice. Between the effects described in this thread and also breathing all that super-dry compressed gas, dehydration is one of your worst physiological enemies while diving.
But it's also one of the easiest things to prevent. So drink lots of water, avoid alcohol and anything that dehydrates, and "be ready to go" warm up that wet suit right after hitting the water!
>*< Fritz
One of my instructors had a variation on this... he said
"There are 2 reasons why you don't need to pee immediately you exit the water after a dive
A) You used the wetsuit and therefore WILL be cleaning your suit in a different rinse bucket to everyone else...
or
B) You aren't hydrated enough and ARE risking your health."
Never forgot that advice, nor my drinks for before or after the dives.
IMMERSION DIURESIS:
On land blood tends to pool in legs due to gravity, but under water gravity is neutralized. This means that the blood centralizes in the body and new blood volume expands the heart’s chambers which release the chemical ANF. This increases urine output. Blood is shifted to your body’s core, and the hypothalamus gland thinks that this means that your total fluid volume is too high and instructs your kidneys to make urine by slowing down the release of anti-diuretic hormone (ADH) increasing fluid output. All this ends up in your bladder filling up, signalling urge to void.
Some divers also claim that as soon they get in to the wet suit they feel that they need to go to the bathroom. That however, probably has a more psychologically explanation.
..a..
On land blood tends to pool in legs due to gravity, but under water gravity is neutralized. This means that the blood centralizes in the body and new blood volume expands the heart’s chambers which release the chemical ANF. This increases urine output. Blood is shifted to your body’s core, and the hypothalamus gland thinks that this means that your total fluid volume is too high and instructs your kidneys to make urine by slowing down the release of anti-diuretic hormone (ADH) increasing fluid output. All this ends up in your bladder filling up, signalling urge to void.
Some divers also claim that as soon they get in to the wet suit they feel that they need to go to the bathroom. That however, probably has a more psychologically explanation.
..a..
traumadiver
Contributor
All this talk about ADH and Immersion Diuresis is giving me flashbacks from Paramedic school. Never thought I would ever have to recall this information again from 10 years ago. Geez, who says school doesnt prepare you for real life.
Thanx for the refresher everyone.
Thanx for the refresher everyone.
peterthewolf
Registered
Hey Docs- Wow, fantastic read! Thanks so much for 'splaining' us, the hormonal and pressure reasons for mondourination.
Here on the CA Northcoast, the water is 45-49F. We do significant surface surface swims to and from in varied wind/swell conditions that can in themselves keep you in decent shape. After 38 diving years, one day several years ago I suddenly concluded that being 100 feet from shore and unable to hold it anymore was not cause for punishment (I've called my mom who assured me childhood training was just peachy)...Let's just say that to date I keep a gallon bottle of wetsuit shampoo on hand and use some after every dive!
Ok, to the point. I have a fast metaboloism, so I eat bkfst 1 hr+ before diving and top it with some carbs. About 20 minutes before and through gearing up, I drink swallows of water. Then just prior to hitting the water, I drink the remainder of that quart. Now I'm f-u-l-l. Like, loosen that cumberbund, and don't inhale too deep. That too-full feeling on swim out can feel restrictive on a full inhalation while snorkeling out on the surface. But I can feel half way through the dive that my body has gone through that water; the ocean is a richer place for my having been there.
Man, have I bought equipment, and I do like that super stretch aqualung suit (7mm) with hooded vest. But I'm cold starting at 38'. I get over that with varied depths, but the cold does affect dehydration. Ok, you'll say, buy a dry $uit. Till them, how about drinking slightly less on shore to cut the bulge factor, and, halfway through the dive, surface and drink up some water from a capped camelback liner stashed in a BC pocket? Out here, it's not unnatural to surface during a dive to reorient ,with the wash rock landscape even if we have a compass, or to hook up with a buddy once in very low vis back on the surface after 1 minute. Other than keeping alert for wind waves and the other things normal to us out here, any reason *not* to hydrate up a little *during* the dive?
Finally, I'm 5'7/144 lbs. Normal and ex health. I just don't have a big stomach to put water in... other than drinking till you feel uncomfortable...is there a problem getting 'too much' water in terms of the cardiac pressures etc?
Here on the CA Northcoast, the water is 45-49F. We do significant surface surface swims to and from in varied wind/swell conditions that can in themselves keep you in decent shape. After 38 diving years, one day several years ago I suddenly concluded that being 100 feet from shore and unable to hold it anymore was not cause for punishment (I've called my mom who assured me childhood training was just peachy)...Let's just say that to date I keep a gallon bottle of wetsuit shampoo on hand and use some after every dive!
Ok, to the point. I have a fast metaboloism, so I eat bkfst 1 hr+ before diving and top it with some carbs. About 20 minutes before and through gearing up, I drink swallows of water. Then just prior to hitting the water, I drink the remainder of that quart. Now I'm f-u-l-l. Like, loosen that cumberbund, and don't inhale too deep. That too-full feeling on swim out can feel restrictive on a full inhalation while snorkeling out on the surface. But I can feel half way through the dive that my body has gone through that water; the ocean is a richer place for my having been there.
Man, have I bought equipment, and I do like that super stretch aqualung suit (7mm) with hooded vest. But I'm cold starting at 38'. I get over that with varied depths, but the cold does affect dehydration. Ok, you'll say, buy a dry $uit. Till them, how about drinking slightly less on shore to cut the bulge factor, and, halfway through the dive, surface and drink up some water from a capped camelback liner stashed in a BC pocket? Out here, it's not unnatural to surface during a dive to reorient ,with the wash rock landscape even if we have a compass, or to hook up with a buddy once in very low vis back on the surface after 1 minute. Other than keeping alert for wind waves and the other things normal to us out here, any reason *not* to hydrate up a little *during* the dive?
Finally, I'm 5'7/144 lbs. Normal and ex health. I just don't have a big stomach to put water in... other than drinking till you feel uncomfortable...is there a problem getting 'too much' water in terms of the cardiac pressures etc?
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It IS possible to drink too much water, but it requires massive consumption (gallons) and is usually only seen in people with significant psychiatric issues. You don't have to worry about overdrinking under normal circumstances. On the other hand, sawtooth profiles are a bit problematic
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