Camelbacks, Hydration and Why I Am A Genius

[DougC]

Some time back on a bicycle forum (I forgot exactly where it was)
someone asked about the usefulness of bladder hydration systems. People
who had tried them said in general that they do make hydrating much
easier. One person noted that they were no good for competition however,
because there was no way to tell how much you were drinking.

This person was using a rather (to me) exact example, of one having a
plan to drink 12 ounces of water per-hour or some such measure, and that
a bladder system gave you no way to measure what you were drinking.
Something about this answer bothered me, and I finally figured out what
it was: the bladder gives you no way to tell how much you're drinking,
but the problem with attempting to determine some super-exact hydration
target is that the target itself shifts with a number of other
variables, and there's no way to tell on the bike what condition your
hydration is.

As it is now, the only reasonably-convenient method people can use to
find out if they were over- or under-hydrated during a ride is to weigh
themselves before the ride and after. What is really needed is a
strain-gauge built onto the seatpost--with a digital readout, so that
you can measure your body weight during the ride, without stopping. The
gauge does not need to be able to determine your /absolute/ weight--but
if you adopted a "weighing position" (such as with your hands on the
tops, elbows straight and resting your feet on the pedals horizontal)
then a strain gauge should be able to pick up a difference. You would
"calibrate" it at the start of a ride, and then have a button (that is
accessible in your "weighing" position) to weigh yourself. The display
would then show if your weight had moved up or down from the starting
weight, and by how much.

The point is that this setup would give a far more accurate
representation of what your weight is doing during a ride.

I am a recumbent zealot--and installing something like this on a
recumbent seat would be considerably more of a hassle,,, but I can't see
any way you could really hydrate accurately without repeatedly weighing
yourself. And I haven't yet heard of anything sold that could perform
this task on the bike, while riding.

This doesn't seem like any great technical difficulty to make.
Does anyone already sell such a thing? Or make one for their own use?
~

 

[Qui si parla Campagnolo]

On Feb 5, 3:55 am, DougC <[email protected]> wrote:
> Some time back on a bicycle forum (I forgot exactly where it was)
> someone asked about the usefulness of bladder hydration systems. People
> who had tried them said in general that they do make hydrating much
> easier. One person noted that they were no good for competition however,
> because there was no way to tell how much you were drinking.
>
> This person was using a rather (to me) exact example, of one having a
> plan to drink 12 ounces of water per-hour or some such measure, and that
> a bladder system gave you no way to measure what you were drinking.
> Something about this answer bothered me, and I finally figured out what
> it was: the bladder gives you no way to tell how much you're drinking,
> but the problem with attempting to determine some super-exact hydration
> target is that the target itself shifts with a number of other
> variables, and there's no way to tell on the bike what condition your
> hydration is.
>
> As it is now, the only reasonably-convenient method people can use to
> find out if they were over- or under-hydrated during a ride is to weigh
> themselves before the ride and after. What is really needed is a
> strain-gauge built onto the seatpost--with a digital readout, so that
> you can measure your body weight during the ride, without stopping. The
> gauge does not need to be able to determine your /absolute/ weight--but
> if you adopted a "weighing position" (such as with your hands on the
> tops, elbows straight and resting your feet on the pedals horizontal)
> then a strain gauge should be able to pick up a difference. You would
> "calibrate" it at the start of a ride, and then have a button (that is
> accessible in your "weighing" position) to weigh yourself. The display
> would then show if your weight had moved up or down from the starting
> weight, and by how much.
>
> The point is that this setup would give a far more accurate
> representation of what your weight is doing during a ride.
>
> I am a recumbent zealot--and installing something like this on a
> recumbent seat would be considerably more of a hassle,,, but I can't see
> any way you could really hydrate accurately without repeatedly weighing
> yourself. And I haven't yet heard of anything sold that could perform
> this task on the bike, while riding.

Errr, how about a water bottle and a watch..'12 ounces per hour",
easy, even on a 'bent.
>
> This doesn't seem like any great technical difficulty to make.
> Does anyone already sell such a thing? Or make one for their own use?
> ~

 

[Pat]

> Errr, how about a water bottle and a watch..'12 ounces per hour",
> easy, even on a 'bent.

Last summer, I realized I was drinking less water on rides. I finally
figured out that it had been (and still was) so windy that I didn't like to
take my hand off of the handlebar long enough to reach down for the water
bottle. I was only drinking at stops. We get a lot of gusty winds here in
Texas and last year was especially weird in that category. So, measuring
how much water you drink using a bottle wouldn't work well here.

Pat in TX

 

[damyth]

On Feb 5, 2:55 am, DougC <[email protected]> wrote:
> Some time back on a bicycle forum (I forgot exactly where it was)
> someone asked about the usefulness of bladder hydration systems. People
> who had tried them said in general that they do make hydrating much
> easier. One person noted that they were no good for competition however,
> because there was no way to tell how much you were drinking.
>
> This person was using a rather (to me) exact example, of one having a
> plan to drink 12 ounces of water per-hour or some such measure, and that
> a bladder system gave you no way to measure what you were drinking.
> Something about this answer bothered me, and I finally figured out what
> it was: the bladder gives you no way to tell how much you're drinking,
> but the problem with attempting to determine some super-exact hydration
> target is that the target itself shifts with a number of other
> variables, and there's no way to tell on the bike what condition your
> hydration is.
>
> As it is now, the only reasonably-convenient method people can use to
> find out if they were over- or under-hydrated during a ride is to weigh
> themselves before the ride and after. What is really needed is a
> strain-gauge built onto the seatpost--with a digital readout, so that
> you can measure your body weight during the ride, without stopping. The
> gauge does not need to be able to determine your /absolute/ weight--but
> if you adopted a "weighing position" (such as with your hands on the
> tops, elbows straight and resting your feet on the pedals horizontal)
> then a strain gauge should be able to pick up a difference. You would
> "calibrate" it at the start of a ride, and then have a button (that is
> accessible in your "weighing" position) to weigh yourself. The display
> would then show if your weight had moved up or down from the starting
> weight, and by how much.
>
> The point is that this setup would give a far more accurate
> representation of what your weight is doing during a ride.
>
> I am a recumbent zealot--and installing something like this on a
> recumbent seat would be considerably more of a hassle,,, but I can't see
> any way you could really hydrate accurately without repeatedly weighing
> yourself. And I haven't yet heard of anything sold that could perform
> this task on the bike, while riding.
>
> This doesn't seem like any great technical difficulty to make.
> Does anyone already sell such a thing? Or make one for their own use?
> ~

Dude, you're no genius.

You start the ride by carrying a full bladder in the hydration pack.
You end the ride carrying an empty bladder, having drank all the
water. Assuming you didn't sweat, the combined weight of of you and
the hydration pack is the same at all times during the ride (the water
in the pack having migrated to your stomach)! And of course, since
one of course sweats and loses water due to respiration during the
ride, I dont possibly see how a strain gauge can determine anything
useful.

 

[peter]

Qui si parla Campagnolo wrote:

> Errr, how about a water bottle and a watch..'12 ounces per hour",
> easy, even on a 'bent.

But only useful if you have some way of knowing that 12oz./hr. is in
fact the right rate to make up for your water usage. Since the rate
of losing water will depend on temperature, humidity, wind, and
exertion level, there's no reason to expect such a specific rate to
hold true on any given ride.
> >
> > This doesn't seem like any great technical difficulty to make.
> > Does anyone already sell such a thing? Or make one for their own use?

Not that I know of. But it wouldn't work as described for the way
most upright riders carry their hydration packs - i.e. on their backs.
The seat post strain gauge would measure the weight of rider plus
hydration pack and therefore wouldn't give a good indication of how
much weight the rider has lost.

 

[Kinky Cowboy]

On 5 Feb 2007 08:48:17 -0800, "damyth" <[email protected]>
wrote:

>On Feb 5, 2:55 am, DougC <[email protected]> wrote:
>>
>> As it is now, the only reasonably-convenient method people can use to
>> find out if they were over- or under-hydrated during a ride is to weigh
>> themselves before the ride and after. What is really needed is a
>> strain-gauge built onto the seatpost--with a digital readout, so that
>> you can measure your body weight during the ride, without stopping.
>>
>> The point is that this setup would give a far more accurate
>> representation of what your weight is doing during a ride.
>>
>>
>> This doesn't seem like any great technical difficulty to make.
>> Does anyone already sell such a thing? Or make one for their own use?
>> ~
>
>Dude, you're no genius.
>
>You start the ride by carrying a full bladder in the hydration pack.
>You end the ride carrying an empty bladder, having drank all the
>water. Assuming you didn't sweat, the combined weight of of you and
>the hydration pack is the same at all times during the ride (the water
>in the pack having migrated to your stomach)! And of course, since
>one of course sweats and loses water due to respiration during the
>ride, I dont possibly see how a strain gauge can determine anything
>useful.

Quite right; what you actually need is just a simple flow meter in the
drinking tube of your Camelbak, and then a thermometer, hygrometer,
anemometer and a set of SRM cranks or a Powertap, all linked in to one
computer so you could properly calculate your fluid requirements based
on temperature, humidity, windspeed and exertion and match that
against your input flow rate. Perhaps the machine could go beep when
it thought you were behind your hydration schedule

Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

 

[Joe Riel]

Kinky Cowboy <[email protected]> writes:

> On 5 Feb 2007 08:48:17 -0800, "damyth" <[email protected]>
> wrote:
>
>>On Feb 5, 2:55 am, DougC <[email protected]> wrote:
>>>
>>> As it is now, the only reasonably-convenient method people can use to
>>> find out if they were over- or under-hydrated during a ride is to weigh
>>> themselves before the ride and after. What is really needed is a
>>> strain-gauge built onto the seatpost--with a digital readout, so that
>>> you can measure your body weight during the ride, without stopping.
>>>
>>> The point is that this setup would give a far more accurate
>>> representation of what your weight is doing during a ride.
>>>
>>>
>>> This doesn't seem like any great technical difficulty to make.
>>> Does anyone already sell such a thing? Or make one for their own use?
>>> ~
>>
>>Dude, you're no genius.
>>
>>You start the ride by carrying a full bladder in the hydration pack.
>>You end the ride carrying an empty bladder, having drank all the
>>water. Assuming you didn't sweat, the combined weight of of you and
>>the hydration pack is the same at all times during the ride (the water
>>in the pack having migrated to your stomach)! And of course, since
>>one of course sweats and loses water due to respiration during the
>>ride, I dont possibly see how a strain gauge can determine anything
>>useful.
>
> Quite right; what you actually need is just a simple flow meter in the
> drinking tube of your Camelbak, and then a thermometer, hygrometer,
> anemometer and a set of SRM cranks or a Powertap, all linked in to one
> computer so you could properly calculate your fluid requirements based
> on temperature, humidity, windspeed and exertion and match that
> against your input flow rate. Perhaps the machine could go beep when
> it thought you were behind your hydration schedule

Better yet, get a central line installed and pump the fluid right into
your veins. I got to go through that regime a couple years ago when I
had my intestine removed. They left the port in for several months
after I came off the TPM. One of my teammates suggested I ought to
figure out how to hook it up for use while riding .

--
Joe Riel

 

[G.T.]

Qui si parla Campagnolo wrote:
> On Feb 5, 3:55 am, DougC <[email protected]> wrote:
>> Some time back on a bicycle forum (I forgot exactly where it was)
>> someone asked about the usefulness of bladder hydration systems. People
>> who had tried them said in general that they do make hydrating much
>> easier. One person noted that they were no good for competition however,
>> because there was no way to tell how much you were drinking.
>>
>> This person was using a rather (to me) exact example, of one having a
>> plan to drink 12 ounces of water per-hour or some such measure, and that
>> a bladder system gave you no way to measure what you were drinking.
>> Something about this answer bothered me, and I finally figured out what
>> it was: the bladder gives you no way to tell how much you're drinking,
>> but the problem with attempting to determine some super-exact hydration
>> target is that the target itself shifts with a number of other
>> variables, and there's no way to tell on the bike what condition your
>> hydration is.
>>
>> As it is now, the only reasonably-convenient method people can use to
>> find out if they were over- or under-hydrated during a ride is to weigh
>> themselves before the ride and after. What is really needed is a
>> strain-gauge built onto the seatpost--with a digital readout, so that
>> you can measure your body weight during the ride, without stopping. The
>> gauge does not need to be able to determine your /absolute/ weight--but
>> if you adopted a "weighing position" (such as with your hands on the
>> tops, elbows straight and resting your feet on the pedals horizontal)
>> then a strain gauge should be able to pick up a difference. You would
>> "calibrate" it at the start of a ride, and then have a button (that is
>> accessible in your "weighing" position) to weigh yourself. The display
>> would then show if your weight had moved up or down from the starting
>> weight, and by how much.
>>
>> The point is that this setup would give a far more accurate
>> representation of what your weight is doing during a ride.
>>
>> I am a recumbent zealot--and installing something like this on a
>> recumbent seat would be considerably more of a hassle,,, but I can't see
>> any way you could really hydrate accurately without repeatedly weighing
>> yourself. And I haven't yet heard of anything sold that could perform
>> this task on the bike, while riding.
>
> Errr, how about a water bottle and a watch..'12 ounces per hour",
> easy, even on a 'bent.

Errr, how about drink when you're thirsty. More and more people are
coming to the conclusion that following some forced drinking scheduled
is inefficient.

Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

 

[Dan]

Kinky Cowboy wrote:
> On 5 Feb 2007 08:48:17 -0800, "damyth" <[email protected]>
> wrote:
>
>> On Feb 5, 2:55 am, DougC <[email protected]> wrote:
>>> As it is now, the only reasonably-convenient method people can use to
>>> find out if they were over- or under-hydrated during a ride is to weigh
>>> themselves before the ride and after. What is really needed is a
>>> strain-gauge built onto the seatpost--with a digital readout, so that
>>> you can measure your body weight during the ride, without stopping.
>>>
>>> The point is that this setup would give a far more accurate
>>> representation of what your weight is doing during a ride.
>>>
>>>
>>> This doesn't seem like any great technical difficulty to make.
>>> Does anyone already sell such a thing? Or make one for their own use?
>>> ~
>> Dude, you're no genius.
>>
>> You start the ride by carrying a full bladder in the hydration pack.
>> You end the ride carrying an empty bladder, having drank all the
>> water. Assuming you didn't sweat, the combined weight of of you and
>> the hydration pack is the same at all times during the ride (the water
>> in the pack having migrated to your stomach)! And of course, since
>> one of course sweats and loses water due to respiration during the
>> ride, I dont possibly see how a strain gauge can determine anything
>> useful.
>
> Quite right; what you actually need is just a simple flow meter in the
> drinking tube of your Camelbak, and then a thermometer, hygrometer,
> anemometer and a set of SRM cranks or a Powertap, all linked in to one
> computer so you could properly calculate your fluid requirements based
> on temperature, humidity, windspeed and exertion and match that
> against your input flow rate. Perhaps the machine could go beep when
> it thought you were behind your hydration schedule
>
> Kinky Cowboy*
>
> *Batteries not included
> May contain traces of nuts
> Your milage may vary
>

Probably need two flow meters, one for in and for a urine catheter.

 

[[email protected]]

> One of my teammates suggested I ought to
> figure out how to hook it up for use while riding .
>
> --
> Joe Riel

Well that is certainly easier when riding a 'bent as the op is doing.
Since the fluid bags need to be higher than your port, a simple pole &
hook hose-clamped to the seat back would acheve the elevation needed.

Rick

 

[Kinky Cowboy]

On Mon, 05 Feb 2007 10:57:35 -0800, "G.T." <[email protected]>
wrote:

>
>Errr, how about drink when you're thirsty. More and more people are
>coming to the conclusion that following some forced drinking scheduled
>is inefficient.
>

Waiting until you're thirsty before you start drinking is a sure route
to dehydration. In normal life, that much dehydration doesn't matter,
but it will be enough to have a deleterious effect on your sporting
performance, and in a long hard race you may never catch up, leaving
you impaired for most of the race duration.

Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

 

[Joe Riel]

"[email protected]" <[email protected]> writes:

>> One of my teammates suggested I ought to
>> figure out how to hook it up for use while riding .
>>
>> --
>> Joe Riel
>
> Well that is certainly easier when riding a 'bent as the op is doing.
> Since the fluid bags need to be higher than your port, a simple pole &
> hook hose-clamped to the seat back would acheve the elevation needed.

The bag doesn't necessarily have to be higher. For saline solution, I
used a gravity fed drip, but for the TPN (total parenteral nutrition),
a battery-powered pump was used. The pump was clever, the thin
plastic tube, which was connected to my port, ran through a bank of
"rollers" that pushed the liquid along by sequentially squeezing the
tube. That maintained sterility. It went into a backpack with the
TPN, a battery-powered camelback.

--
Joe Riel

 

[Mike Jacoubowsky]

>> Errr, how about a water bottle and a watch..'12 ounces per hour",
>> easy, even on a 'bent.
>
> Errr, how about drink when you're thirsty. More and more people are
> coming to the conclusion that following some forced drinking scheduled is
> inefficient.

People might think that they drink when they're thirsty, but more likely
they've developed a "schedule" that generally works for them, but tend not
to alter it for differing conditions. I see this most frequently at
altitude, where people tend to drink the same as they do at lower
elevations, yet the need is considerably greater, due to the amount of fluid
loss with each breath (and due to thinner air, you're breathing more often).
And since some of the symptoms of dehydration and altitude sickness are
similar, people tend to think the bad way they feel at altitude is due to
altitude sickness, not their lack of fluid intake.

--Mike--
Chain Reaction Bicycles
www.ChainReaction.com

 

[Ron Ruff]

> I see this most frequently at
> altitude, where people tend to drink the same as they do at lower
> elevations, yet the need is considerably greater, due to the amount of fluid
> loss with each breath

I don't know about that one, Mike. When I lived in Kauai (85F,
70%RH... pretty much all the time) I drank as much as I possibly could
and it still wasn't enough (ever). On a 4hr ride I'd down 10lbs of
fluid, not pee at all, and be 10lbs lighter when I got home. Now I
live at 7400ft and hardly need to drink at all... so whatever I'm
losing through respiration isn't much compared to what I was sweating
before. Even if it was warm here, at least the sweat evaporates easily
so it does some good.

 

[G.T.]

"Kinky Cowboy" <[email protected]> wrote in message
news:[email protected]...
> On Mon, 05 Feb 2007 10:57:35 -0800, "G.T." <[email protected]>
> wrote:
>
>>
>>Errr, how about drink when you're thirsty. More and more people are
>>coming to the conclusion that following some forced drinking scheduled
>>is inefficient.
>>
>
> Waiting until you're thirsty before you start drinking is a sure route
> to dehydration. In normal life, that much dehydration doesn't matter,
> but it will be enough to have a deleterious effect on your sporting
> performance, and in a long hard race you may never catch up, leaving
> you impaired for most of the race duration.
>

Depends on who the athlete is:

"In fact, a study published in the New England Journal of Medicine (April,
2005) found that 13 percent of Boston Marathon runners developed
hyponatremia from drinking too much water."

""Even though I increased my salt intake the week before the race, I also
drank almost three liters of water beforehand and drank more throughout. I
knew at mile seven that something was wrong and I was in trouble," said
Guevara, a 27-year old running enthusiast from Centerville, VA. "In the
medical tent, I was woozy and slurring my speech and once someone took my
sodium levels, they realized I had hyponatremia and gave me some hot, salty
broth. The scary thing is, a few years ago, I may have been treated for
dehydration - with more water."

I'd suggest that most people don't need to drink in advance and they
definitely shouldn't be forcing themselves to drink.

I can't find them now but with the publicity surrounding Jennifer Strange's
death I saw a couple cites of recent studies that are taking issue with the
whole drink before you're thirsty meme.

Greg

 

[Kinky Cowboy]

On Mon, 5 Feb 2007 15:31:45 -0800, "G.T." <[email protected]>
wrote:

>
>"Kinky Cowboy" <[email protected]> wrote in message
>news:[email protected]...
>> On Mon, 05 Feb 2007 10:57:35 -0800, "G.T." <[email protected]>
>> wrote:
>>
>>>
>>>Errr, how about drink when you're thirsty. More and more people are
>>>coming to the conclusion that following some forced drinking scheduled
>>>is inefficient.
>>>
>>
>> Waiting until you're thirsty before you start drinking is a sure route
>> to dehydration. In normal life, that much dehydration doesn't matter,
>> but it will be enough to have a deleterious effect on your sporting
>> performance, and in a long hard race you may never catch up, leaving
>> you impaired for most of the race duration.
>>
>
>Depends on who the athlete is:
>
>"In fact, a study published in the New England Journal of Medicine (April,
>2005) found that 13 percent of Boston Marathon runners developed
>hyponatremia from drinking too much water."
>
>""Even though I increased my salt intake the week before the race, I also
>drank almost three liters of water beforehand and drank more throughout. I
>knew at mile seven that something was wrong and I was in trouble," said
>Guevara, a 27-year old running enthusiast from Centerville, VA. "In the
>medical tent, I was woozy and slurring my speech and once someone took my
>sodium levels, they realized I had hyponatremia and gave me some hot, salty
>broth. The scary thing is, a few years ago, I may have been treated for
>dehydration - with more water."
>
>I'd suggest that most people don't need to drink in advance and they
>definitely shouldn't be forcing themselves to drink.
>
>I can't find them now but with the publicity surrounding Jennifer Strange's
>death I saw a couple cites of recent studies that are taking issue with the
>whole drink before you're thirsty meme.
>

There are two different problems, and it doesn't help to conflate
them. Anybody exercising hard, especially in a hot and or humid
environment, will lose a lot of both water and sodium through
perspiration. Trying to replace only one of these, by drinking only
plain water, leads to hyponatremia just as surely as not replacing the
water leads to dehydration.

By drinking a properly balanced solution of electrolytes in water, you
can avoid both problems.

There's an online hydration calculator, with sport specific inputs, at
http://www.hydraopt.com

Taking reasonable guesses at the size and weight of this Guevara
fellow, he probably needed to drink no more than about 3.5 litres for
the marathon; by taking 3 litres of water and no electrolytes at the
start, he was setting himself up for trouble.

Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

 

[G.T.]

"Kinky Cowboy" <[email protected]> wrote in message
news:[email protected]...
> On Mon, 5 Feb 2007 15:31:45 -0800, "G.T." <[email protected]>
> wrote:
>
>>Depends on who the athlete is:
>>
>>"In fact, a study published in the New England Journal of Medicine (April,
>>2005) found that 13 percent of Boston Marathon runners developed
>>hyponatremia from drinking too much water."
>>
>>""Even though I increased my salt intake the week before the race, I also
>>drank almost three liters of water beforehand and drank more throughout. I
>>knew at mile seven that something was wrong and I was in trouble," said
>>Guevara, a 27-year old running enthusiast from Centerville, VA. "In the
>>medical tent, I was woozy and slurring my speech and once someone took my
>>sodium levels, they realized I had hyponatremia and gave me some hot,
>>salty
>>broth. The scary thing is, a few years ago, I may have been treated for
>>dehydration - with more water."
>>
>>I'd suggest that most people don't need to drink in advance and they
>>definitely shouldn't be forcing themselves to drink.
>>
>>I can't find them now but with the publicity surrounding Jennifer
>>Strange's
>>death I saw a couple cites of recent studies that are taking issue with
>>the
>>whole drink before you're thirsty meme.
>>
>
> There are two different problems, and it doesn't help to conflate
> them. Anybody exercising hard, especially in a hot and or humid
> environment, will lose a lot of both water and sodium through
> perspiration. Trying to replace only one of these, by drinking only
> plain water, leads to hyponatremia just as surely as not replacing the
> water leads to dehydration.
>
> By drinking a properly balanced solution of electrolytes in water, you
> can avoid both problems.
>
> There's an online hydration calculator, with sport specific inputs, at
> http://www.hydraopt.com
>
> Taking reasonable guesses at the size and weight of this Guevara
> fellow, he probably needed to drink no more than about 3.5 litres for
> the marathon; by taking 3 litres of water and no electrolytes at the
> start, he was setting himself up for trouble.
>

Actually, I see that her first name, Katherine, wasn't in that quote so your
estimate of size and weight was probably way off since she is a she.

Greg

 

[Tim McNamara]

In article <[email protected]>,
"G.T." <[email protected]> wrote:

> Qui si parla Campagnolo wrote:
> > On Feb 5, 3:55 am, DougC <[email protected]> wrote:
> >
> >> As it is now, the only reasonably-convenient method people can use
> >> to find out if they were over- or under-hydrated during a ride is
> >> to weigh themselves before the ride and after. What is really
> >> needed is a strain-gauge built onto the seatpost--with a digital
> >> readout, so that you can measure your body weight during the ride,
> >> without stopping. The gauge does not need to be able to determine
> >> your /absolute/ weight--but if you adopted a "weighing position"
> >> (such as with your hands on the tops, elbows straight and resting
> >> your feet on the pedals horizontal) then a strain gauge should be
> >> able to pick up a difference. You would "calibrate" it at the
> >> start of a ride, and then have a button (that is accessible in
> >> your "weighing" position) to weigh yourself. The display would
> >> then show if your weight had moved up or down from the starting
> >> weight, and by how much.
> >
> > Errr, how about a water bottle and a watch..'12 ounces per hour",
> > easy, even on a 'bent.
>
> Errr, how about drink when you're thirsty. More and more people are
> coming to the conclusion that following some forced drinking
> scheduled is inefficient.

LOL! Greg, that's just too danged easy and low-tech! It'll never
sell.

 

[Tim McNamara]

In article <[email protected]>,
Kinky Cowboy <[email protected]> wrote:

> On Mon, 05 Feb 2007 10:57:35 -0800, "G.T." <[email protected]>
> wrote:
>
> >
> >Errr, how about drink when you're thirsty. More and more people are
> >coming to the conclusion that following some forced drinking
> >scheduled is inefficient.
> >
>
> Waiting until you're thirsty before you start drinking is a sure
> route to dehydration. In normal life, that much dehydration doesn't
> matter, but it will be enough to have a deleterious effect on your
> sporting performance, and in a long hard race you may never catch up,
> leaving you impaired for most of the race duration.

That's old-school thinking, K.C. Newer research has found that
overhydrating is done easily and can lead to serious health
consequences. There's been some threads on this recently.

 

[Tim McNamara]

In article <[email protected]>,
Kinky Cowboy <[email protected]> wrote:

> There are two different problems, and it doesn't help to conflate
> them. Anybody exercising hard, especially in a hot and or humid
> environment, will lose a lot of both water and sodium through
> perspiration. Trying to replace only one of these, by drinking only
> plain water, leads to hyponatremia just as surely as not replacing
> the water leads to dehydration.
>
> By drinking a properly balanced solution of electrolytes in water,
> you can avoid both problems.

Sorry, but it can't be done that way. A concentration of electrolytes
like that would make you puke your guts out. The concentrations in
sports drinks are low. We've been trained to drink too much when
exercising, with research funded by companies like Gatorade whose
motives may not be as pure as one might hope.