Wing Tape - Does Thickness Affect Performance?

Now. Isn't it possible that we have perfectly adequate physiology and
don't need to take any more than normal precautions against dehydration?

Just Yes or No will do. Simple answer--Yes
but incomplete. Hydration is one parameter. Renal flow is another.

Hartley Falbaum

Hartley,
Could you comment on the thoughts below.
On a few flights, I would be peeing constantly but not sweating. I
was hydrated at the beginning of the flight, as I am very
conscientious about it. The legs were very cold, to the point of not
having very good control of my legs and feet when stepping out the
cockpit. The rest of the body was reasonably comfortable during the
flight. I would assume that due to the constrictions of the vessels in
the legs and lower body
extra fluids had to be expelled.
Can an acute dehydration occur due to that process in flight, should
one fly shortly there after in much warmer and lower altitude with
sunny conditions?
Regards
Udo

Udo

Udo, John:

I'll do a bit of review and try to formulate a clear answer in "educated
layman's" terms. The full technical explanation is a bit soporific and not
really necessary for the purpose at hand..

--
Hartley Falbaum

"jcarlyle" wrote in message
ups.com...
Hartley, your point that renal physiology is extensively researched is
well taken. Clearly it isn't my field, and therefore the links, to me,
were incomprehensible - I couldn't learn a thing from them to help me
understand my situation. You seem well versed in the area; if you
would be so kind as to offer a possible explanation as to the
anomalous bodily response that Graeme and I exhibit I'm eager to be
educated.

Bill Dean's link was very informative regarding thirst and
dehydration. Dr. Dan Johnson has written another paper that is
pertinent to this discussion: http://amygdala.danlj.org/~danlj/
Soaring/Clues/index.html In chapter 5 you'll see that Dan's
recommended in-flight urinary system is Depends. Diapers have a very
high "ick" factor for me, but there's no denying their installation
ease and utter simplicity of use. I guess that since Depends weren't
recommended before in this discussion, the "ick" factor predominates
with other pilots.

-John

Thanks, Hartley, I appreciate that!

-John

On Jan 28, 1:54 pm, "HL Falbaum" wrote:
Udo, John:

I'll do a bit of review and try to formulate a clear answer in "educated
layman's" terms. The full technical explanation is a bit soporific and not
really necessary for the purpose at hand..

HL Falbaum wrote:

Maybe---do you really know that you are not near the end? Next time you fly
on a nice hot day, measure your urine output and check the color. If you
can, check the specific gravity---(range 1.000 to 1.030 on the instrument
will be sufficient). If you are above 200 cc and below 1.015 for a 6 hr
flight then you're OK

Thanks, Hartley. That's very useful information. I have graduated bags
that came with the Texas condoms I haven't yet needed and I'll use one
of those to check volume. I'm sure I can get hold of a hydrometer.

I think a lot of people will find those criteria helpful.

GC

"jcarlyle" wrote in message
oups.com...
Thanks, Hartley, I appreciate that!

-John

On Jan 28, 1:54 pm, "HL Falbaum" wrote:
Udo, John:

I'll do a bit of review and try to formulate a clear answer in "educated
layman's" terms. The full technical explanation is a bit soporific and
not
really necessary for the purpose at hand..


Well--here it is FWIW:
Sorry its long but it does not lend itself well to a one paragraph answer.

This is the short explanation of renal function and water management for
glider pilots. First a few explanations and basic facts.
Water exists in the human body in two basic "compartments". Inside the cells
( intracellular fluid "ICF") and outside the cells (extracellular fluid
"ECF"). Visualize this as small, close together, islands in a vast swamp.
This fluid is not just water, but ions and small protien molecules. The
major players are Sodium, Potassium, Bicarbonate, and Ammonium. These
regulate cell function and acid-base balance, among other things. They
(water and solutes)are transported back and forth across cell membranes by
active "pumps", which are part of the cell, and osmotic pressure gradients,
which transfers water.

We gain water by drinking, and by metabolism of foods, as well as extraction
of water from the foods (think watermelon, celery, oranges, etc). We lose
water by breathing out water vapor, by direct transpiration from skin,
sweating, and urine production. The amounts vary with temperature, air
moisture content, ambient pressure, and exercise.

Breathing, at sea level pressure, and standard atmosphere temperature and
moisture, and at rest loses us about 375 to 500 cc per day. Much more at
high altitude and on oxygen.Transpiration, about 250 to 350 cc per day,
while sweating and urination can be quite variable, as we all know. The US
Army Surgeons Handbook suggests that total losses can approach 15 liters per
day in combat troops--flack vests, equipment, heat, exertion and the like.
Sweat contains salt, but not as concentrated as in the plasma, or ECF/ICF.

The body produces, just by metabolizing, a certain amount of wastes per day
which the kidneys must remove. This requires about 400 cc of urine per day,
assuming normal kidney function.

So here's how it works---blood flows through capilliaries in the kidney,
surrounding the glomerulus. This is a filter, allowing out water and the
solutes mentioned above. Then the filtrate passes to the renal tubule (a
little tube) and the capilliaries follow. The tubule is an active structure
and pumps water back into the capps but leaves some for the tubule. Under
the influence of the pituitary gland, the water is regulated by Vasopressin
(AntiDiuretic Hormone) and the Sodium by Angiotensin. ADH is a osmotic
regulator, and Angiotension is a blood pressure regulator. Acid base balance
is controlled by pumping Bicarbonate and Ammonium ( and also by the lungs,
adjusting CO2). Once the tubules have done their job, the remainder is
pumped by pressure and peristalsis (muscular contraction waves in a tubular
structure) down the ureter into the bladder.

The bladder is a muscular-walled sack which can contract involuntarily, and
this contraction can be inhibited or facilitated by conscious control. The
sphincter (think of a O-ring which can change diameter and thickness)
controls the flow, and is under voluntary control and well as involuntary
control. (This is the secret of toilet training.). When the bladder begins
to get full, it sigmals the spinal cord to produce the "micturition"
(peeing) reflex, and you get the signal. This starts at about 150 cc and
comes and goes untill 4-500 cc, when the bladder is full. The reason it
comes and goes is that it is a pressure signal, not a volume signal. The
bladder, being a muscle, can relax, pressure will decrease and it becomes
larger in capicty. (this is the other secret of toilet training).
Eventually, it cannot be ignored, as you all know! You relax the sphincter,
command bladder contraction facilitation and abdominal wall
contraction--and, whew! relief!

If we don't provide a sufficient flow rate to the tubules, they will
concentrate the wastes as best they can, until the pumps can no longer
overcome the osmotic pressure gradient, then they give up! If we don't empty
the bladder, we eventually cannot overcome the pressure gradient and the
tubules and the glomeruli give up. If the wastes are too concentrated too
long, we form Calcium or Oxalate stones.

So what do we need to do? We must provide mild excesses of water and
electrolytes to the system and let it take what it needs. How do we know we
have done that--? Well, we know that we need to excrete at least 400-500 cc
of urine per 24hr. We know that urine should not be overly concentrated. We
know that when we sleep, our blood pressure, heart rate and respiratory rate
is decresed, thereby requiring less urine output. Therefore we need to
excrete more urine during the day. Plan 35-50 cc per hour, and moderate
concentration--light to medium yellow. If we do that, we are well hydrated
and our urinary system is functioning well-no danger. Acid-base balance is
maintained (another source of cognitive impairment).If we drink enough to
maintain those pasameters, we should be fine. Water is good if we are not
doing muscular effort (as we are not losing electrolytes much), Gatorade or
Powerade if we are doing heavy muscular effort (assemble 3 ASW20B's in a
row)--but be careful. The glucose can cause an insulin spike, and drop your
blood sugar.

In the final analysis, it's really simple. Drink enough to maintain about a
40-50cc/ hr urine output. For those who say "I don't pee much", I
say--measure--maybe it's enough after all-maybe not. To those who measure
their flights by "pee bags", well-enjoy, but you may be overdoing it. (I
have seen a FULL 1 gallon ziplock bag come out of a glider after landing!)

I hope this helps

Hartley Falbaum

HL Falbaum wrote:

Well--here it is FWIW:

Thanks, Hartley. It's worth more than all the other fire and brimstone
warnings put together. Great.

GC

Sorry its long but it does not lend itself well to a one paragraph answer.

This is the short explanation of renal function and water management for
glider pilots. First a few explanations and basic facts.
Water exists in the human body in two basic "compartments". Inside the cells
( intracellular fluid "ICF") and outside the cells (extracellular fluid
"ECF"). Visualize this as small, close together, islands in a vast swamp.
This fluid is not just water, but ions and small protien molecules. The
major players are Sodium, Potassium, Bicarbonate, and Ammonium. These
regulate cell function and acid-base balance, among other things. They
(water and solutes)are transported back and forth across cell membranes by
active "pumps", which are part of the cell, and osmotic pressure gradients,
which transfers water.

We gain water by drinking, and by metabolism of foods, as well as extraction
of water from the foods (think watermelon, celery, oranges, etc). We lose
water by breathing out water vapor, by direct transpiration from skin,
sweating, and urine production. The amounts vary with temperature, air
moisture content, ambient pressure, and exercise.

Breathing, at sea level pressure, and standard atmosphere temperature and
moisture, and at rest loses us about 375 to 500 cc per day. Much more at
high altitude and on oxygen.Transpiration, about 250 to 350 cc per day,
while sweating and urination can be quite variable, as we all know. The US
Army Surgeons Handbook suggests that total losses can approach 15 liters per
day in combat troops--flack vests, equipment, heat, exertion and the like.
Sweat contains salt, but not as concentrated as in the plasma, or ECF/ICF.

The body produces, just by metabolizing, a certain amount of wastes per day
which the kidneys must remove. This requires about 400 cc of urine per day,
assuming normal kidney function.

So here's how it works---blood flows through capilliaries in the kidney,
surrounding the glomerulus. This is a filter, allowing out water and the
solutes mentioned above. Then the filtrate passes to the renal tubule (a
little tube) and the capilliaries follow. The tubule is an active structure
and pumps water back into the capps but leaves some for the tubule. Under
the influence of the pituitary gland, the water is regulated by Vasopressin
(AntiDiuretic Hormone) and the Sodium by Angiotensin. ADH is a osmotic
regulator, and Angiotension is a blood pressure regulator. Acid base balance
is controlled by pumping Bicarbonate and Ammonium ( and also by the lungs,
adjusting CO2). Once the tubules have done their job, the remainder is
pumped by pressure and peristalsis (muscular contraction waves in a tubular
structure) down the ureter into the bladder.

The bladder is a muscular-walled sack which can contract involuntarily, and
this contraction can be inhibited or facilitated by conscious control. The
sphincter (think of a O-ring which can change diameter and thickness)
controls the flow, and is under voluntary control and well as involuntary
control. (This is the secret of toilet training.). When the bladder begins
to get full, it sigmals the spinal cord to produce the "micturition"
(peeing) reflex, and you get the signal. This starts at about 150 cc and
comes and goes untill 4-500 cc, when the bladder is full. The reason it
comes and goes is that it is a pressure signal, not a volume signal. The
bladder, being a muscle, can relax, pressure will decrease and it becomes
larger in capicty. (this is the other secret of toilet training).
Eventually, it cannot be ignored, as you all know! You relax the sphincter,
command bladder contraction facilitation and abdominal wall
contraction--and, whew! relief!

If we don't provide a sufficient flow rate to the tubules, they will
concentrate the wastes as best they can, until the pumps can no longer
overcome the osmotic pressure gradient, then they give up! If we don't empty
the bladder, we eventually cannot overcome the pressure gradient and the
tubules and the glomeruli give up. If the wastes are too concentrated too
long, we form Calcium or Oxalate stones.

So what do we need to do? We must provide mild excesses of water and
electrolytes to the system and let it take what it needs. How do we know we
have done that--? Well, we know that we need to excrete at least 400-500 cc
of urine per 24hr. We know that urine should not be overly concentrated. We
know that when we sleep, our blood pressure, heart rate and respiratory rate
is decresed, thereby requiring less urine output. Therefore we need to
excrete more urine during the day. Plan 35-50 cc per hour, and moderate
concentration--light to medium yellow. If we do that, we are well hydrated
and our urinary system is functioning well-no danger. Acid-base balance is
maintained (another source of cognitive impairment).If we drink enough to
maintain those pasameters, we should be fine. Water is good if we are not
doing muscular effort (as we are not losing electrolytes much), Gatorade or
Powerade if we are doing heavy muscular effort (assemble 3 ASW20B's in a
row)--but be careful. The glucose can cause an insulin spike, and drop your
blood sugar.

In the final analysis, it's really simple. Drink enough to maintain about a
40-50cc/ hr urine output. For those who say "I don't pee much", I
say--measure--maybe it's enough after all-maybe not. To those who measure
their flights by "pee bags", well-enjoy, but you may be overdoing it. (I
have seen a FULL 1 gallon ziplock bag come out of a glider after landing!)

I hope this helps

Hartley Falbaum

Hartley, that is a very, very informative write up. It's quite clear,
about a subject I've not been exposed to before. Thanks so much for
taking the time to do it!

Doing some quick math, I see the following:

1. Good urine output is 40-50 ml/hr. For a 6 hour flight, that's
240-300 ml. An average bladder holds 400-500 ml. So IF you empty your
bladder before flight, and IF you're drinking at the optimal
rehydration rate, an average person shouldn't have to pee in flight.

2. Sweating water loss is extremely variable, while urine,
transpiration and breathing losses combined should average about 65-85
ml/hr. If you have 64 ounces of water, you can ration that during 6
hours to 325 ml/hr (11 oz/hr). That leaves 240-260 ml/hr available to
sweat out.

I'll check my urine output the next long flight I take. If it's pale
yellow, and the quantity yields about 40-50 ml/flight hour, I'll know
I've compensated for sweating. And based on point 1, I'm not going to
worry about peeing in-flight (although I will pack some Travel Johns,
just to be prepared)!

-John

On Jan 29, 6:06 pm, "HL Falbaum" wrote:
This is the short explanation of renal function and water management for
glider pilots. First a few explanations and basic facts.

[huge snip]

In the final analysis, it's really simple. Drink enough to maintain about a
40-50cc/ hr urine output. For those who say "I don't pee much", I
say--measure--maybe it's enough after all-maybe not. To those who measure
their flights by "pee bags", well-enjoy, but you may be overdoing it. (I
have seen a FULL 1 gallon ziplock bag come out of a glider after landing!)

Hartley Falbaum

Looks like you guys have the idea. I'm glad it helps

--
Hartley Falbaum

"jcarlyle" wrote in message
ups.com...
Hartley, that is a very, very informative write up. It's quite clear,
about a subject I've not been exposed to before. Thanks so much for
taking the time to do it!

Doing some quick math, I see the following:

1. Good urine output is 40-50 ml/hr. For a 6 hour flight, that's
240-300 ml. An average bladder holds 400-500 ml. So IF you empty your
bladder before flight, and IF you're drinking at the optimal
rehydration rate, an average person shouldn't have to pee in flight.

2. Sweating water loss is extremely variable, while urine,
transpiration and breathing losses combined should average about 65-85
ml/hr. If you have 64 ounces of water, you can ration that during 6
hours to 325 ml/hr (11 oz/hr). That leaves 240-260 ml/hr available to
sweat out.

I'll check my urine output the next long flight I take. If it's pale
yellow, and the quantity yields about 40-50 ml/flight hour, I'll know
I've compensated for sweating. And based on point 1, I'm not going to
worry about peeing in-flight (although I will pack some Travel Johns,
just to be prepared)!

-John

On Jan 29, 6:06 pm, "HL Falbaum" wrote:
This is the short explanation of renal function and water management for
glider pilots. First a few explanations and basic facts.

[huge snip]

In the final analysis, it's really simple. Drink enough to maintain about
a
40-50cc/ hr urine output. For those who say "I don't pee much", I
say--measure--maybe it's enough after all-maybe not. To those who measure
their flights by "pee bags", well-enjoy, but you may be overdoing it. (I
have seen a FULL 1 gallon ziplock bag come out of a glider after
landing!)

Hartley Falbaum

jcarlyle wrote:

1. Good urine output is 40-50 ml/hr. For a 6 hour flight, that's
240-300 ml. An average bladder holds 400-500 ml. So IF you empty your
bladder before flight, and IF you're drinking at the optimal
rehydration rate, an average person shouldn't have to pee in flight.

Can the bladder actually be emptied? Is there residual urine, and how
much for the average male?


Jack

Jack, this question would be best answered by Hartley - I'm a
physicist, not a physician. But since we're talking 60-75% full in the
above example, I imagine there would be some capacity left - YMMV. The
wild card is the individual himself - as has been pointed out the
prostrate gland in males starts enlarging above age 50, affecting the
bladder, urge and ability to go.

-John

On Jan 30, 12:53 pm, Jack wrote:
Can the bladder actually be emptied? Is there residual urine, and how
much for the average male?