[Sca-cooks] On hydration, and rehydration- Pennsic is a coming on ; -)

[Phlip]

Galen, our former Chirurgeon General, posted this to our SCA-Chirurgeon's
List, and has given me permission to post it to the various Cook's Lists I'm
on,  I figure that it's very worthwhile information, and it's very worth
spreading around, particularly to the
people who feed their camps and set up the dayboards. There's also a recipe
at the end, which contains his suggestion for a drink that is less obviously
OOP than <shudder> the ubiquitous Gatorade.

One thing that isn't mentioned specificly in the article, that we also
discussed on Chirurgeon's List, was that some people with certain physical
problems, usually relating to congestive heart disease and water retention,
might be subject to difficulties from water retention when too many
electrolytes are added- if this may be you, or you have some other health
condition which requires dietary monitoring of fluid input and output, you
might want to take this to your physician, and ask him what this specificly
might mean to you.

Ene bichizh ogsen baina shuu...

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There has been a long-standing argument about how to properly hydrate
during SCA activities. There are proponents of everything from pure
water up through full-strength sports drinks with various additives.
While the Ether sings with the debate and sports drink companies rake
in the guineas, recent studies have thrown some light on this arcane
topic.

In order for the body to operate at peak efficiency, it needs to do
four things: 1) maintain body temperature 2) maintain hydration 3)
maintain energy levels, and 4) maintain electrolytes (salts,
especially sodium).

Peak exercise efficiency occurs at a body temperature slightly above
normal (thus the recommendation to "warm up" prior to exercise). To
keep from overheating, the body produces sweat which cools by
evaporation. The sweat contains water and salt, however the
concentration of salt in sweat is less than in the blood. Therefore,
when you sweat, you lose water faster than you lose salt. As you
become more used to the heat, the sweat becomes even more dilute and
you lose even more water in proportion to the salt loss. This means
it is much more important to replace water than salt, at least in the
short run. Most SCA combat activities don't last long enough to
require additional energy supplements (such as carbohydrates) during
that activity. Energy can be replenished by having a small snack
between bouts in a list. During extended melees or wars there may be
benefit to rehydrating with a carbohydrate-containing drink.

What is the best way to replenish what the body needs? At a minimum,
you should be drinking water. The best method is taking small amounts
frequently, such as 8 oz (240 mL) every 15 minutes. Long distance
runners that drink 500 mL (one pint) an hour during a race lose 5 -
6% of their body weight - all from water loss. Daily water
requirements range from 2 L (2 quarts) in normal climates with low
exercise to 15 L (4 gallons) with heavy exercise in the desert. If
you want to know how much water you're loosing, weigh yourself before
and after exercise (naked - you don't want to weigh the sweat soaked
into clothing). The difference is the amount of water you've lost.
The best way to tell if you're adequately hydrated is by paying
attention to your urine. If it's been more than a couple of hours
since you've visited the Port-a-Castle, you're probably not
adequately hydrated. Your urine should be no darker than weak
lemonade. Also, if you're thirsty, you're already 1 - 3% dehydrated.

The salt losses are more than adequately replaced by eating a normal
diet. The goal is to replace water loss minute-by-minute and salt
losses day-by-day. While there have been reports in the news and
sports magazines about people having problems from drinking excessive
water (hyponatremia or water intoxication), this is actually very
rare and usually only seen in endurance races such as ultramarathons
where the participant drinks excessive amounts of water over several
hours of participation. Dehydration is much more common in SCA
activities. Don't hold off drinking water for fear of this rare
condition.

The down-side to water is not everybody finds it tasty, especially
when you have to choke down the amounts it takes to remain well-
hydrated. This is probably the biggest reason to use a flavoring in
the water. Also, water will sometimes satisfy your thirst before
you've drunk enough to replenish your body's stores. Some salt in the
water will also help encourage drinking more.

The ideas about effects of the carbohydrate (sugar) content of sports
drinks has changed over the years. Some studies from the 1960s showed
that carbohydrates in drinks slowed the rate that they are absorbed
from the stomach. This is the reasoning behind the recommendation to
dilute sports drinks in half. More recent studies have shown this not
to be true. However, drinks with more than about 10% carbohydrate
content can cause cramps, nausea, and diarrhea. Not something you
want to have in the finals of Crown Tourney, or, as one author put
it, "You'll be running, but not necessarily on the field!" Products
that are under 8% carbohydrate do not need to be diluted. Gatorade®
at its recommended strength is 6% carbohydrate, and therefore does
not need to be diluted. Diluting the drinks can make the mixes go
farther and can make limited money and/or supplies last longer. The
composition of several sports drinks can be found at:
http://www.powerbar.com/Products/Beverage/BevSystem/ProductComparsonCh
art10-16.pdf

A misconception commonly encountered is that drinking cold drinks
causes stomach cramps and delays stomach emptying. This has not been
borne out in experimental trials. In fact, cold liquids stimulate the
emptying of the stomach. Cool drinks are probably still better
tolerated than ice cold (ever get a `brain freeze'?)

If you use carbohydrate-containing drinks, be careful that the
containers are protected from insects. Bees and other stinging
insects especially like sweet drinks. Rapidly swigging down a drink
that contains a bee quenching his thirst can be very surprising for
both the bee and the drinker, with disastrous results for both.
Sports-top bottles are great for keeping the insects out and are easy
to squirt through most helms. Soda cans are terrible as you can't see
what you're drinking - be it hornet or cigarette butt! Make sure
sweet liquids are properly stored and reusable containers are
thoroughly cleaned as bacteria grow most heartily in sweet liquids.

Drinks that should be avoided are those that contain alcohol,
caffeine, carbonation, and fruit juices. Alcohol and caffeine cause
the kidneys to produce more urine, making dehydration worse. Make
sure you are thinking ahead - don't overindulge on these dehydrating
drinks the day before being exposed to hot environments or heavy
exercise. Start the day with a full tank. Carbonation can cause you
to feel more full due to the release of carbon dioxide in the stomach
reducing the amount of fluid you'll drink and possibly causing
cramping and discomfort during exercise. Soft drinks are both
carbonated and have high carbohydrate concentrations. Fruit juices
are typically well above the recommended 10% carbohydrate level. Salt
tablets should never be used as they irritate the stomach and can
easily send a person's salt levels too high, which can also be life-
threatening. Since the average diet contains well above the required
amounts of sodium, salt tablets are never recommended.

Some drinks add supplements as "energy enhancers." These are
essentially all marketing hype and have not been shown to improve
performance. Some additives can be dangerous, if not deadly. Ephedra
has recently been removed from the US market due to its association
with numerous deaths, including several from heat stroke. Other
additives for improved energy (usually caffeine or its "natural"
cousin guarana) should be avoided for the reasons previously stated.
Creatine has been commonly used as a muscle-building and recovery
aid. It has been associated with dehydration and has been associated
with at least one death due to dehydration. Creatine pulls water into
the muscle and out of the circulation. That's how it makes the
muscles look bigger, but the gain is water, not muscle. It has been
shown to improve certain quick-energy burst activities such as
sprinting, but the improvements have been extremely minimal (about 1
second of extra energy). The advantages are certainly not enough to
justify the cost or the risk. Likewise protein supplements put an
additional load on the kidneys without any significant gains over
what you get in a normal diet.

A very well-liked drink that I call "Friar Galen's Holy Water" has
been loved by fighters at many hot summer practices is made by
slicing and squeezing a dozen lemons and six oranges into the
ubiquitous 5-gallon water container. Add 2½ to 3 gallons of water and
a bag of ice. It's more flavorful if it sets for a few hours before
adding the ice and serving. If you want to make it very close in
carbohydrate and sodium content to Gatorade®, add 3 cups of sugar and
3 tsp of table salt to the basic mix. Based on 3 gallons of water
this mix will contain 6% carbohydrate and 635 mg of sodium per
liter.

Don't let the hype of the drink companies get in the way of taking
proper care of yourself or your SCA brethren. A drink that has the
proper balance of nutrients does no good if no one will drink it.
Pick a flavoring system that your local group likes and will drink
plenty of and make sure everyone is staying adequately hydrated. The
makers of the Camel Back® system got it right when they
said: "Hydrate or Die!"

References:
Bookspan, Jolie. Health & Fitness in Plain English, 2nd Edition.
Healthy Learning. 2002.

The Textbooks of Military Medicine: Medical Aspects of Harsh
Environments, Vol 1. The Borden Institute. 2002.
http://www.bordeninstitute.army.mil/medaspofharshenvrnmnts/def
ault_index.htm
Chapter 5. Pathophysiology of Heatstroke
Chapter 6. Prevention of Heat Illness

Armstrong, Lawrence E. Performing in Extreme Environments. Human
Kinetics. 2000.

Welsh, Ralph S., Mark Davis, J.; Burke, Jean R.; Williams, Harriet G.
Carbohydrates and physical/mental performance during intermittent
exercise to fatigue. Medicine & Science in Sports & Exercise. 34
(4):723-731, April 2002.
http://www.ms-se.com/pt/re/msse/abstract.00005768-200204000-
00025.htm;jsessionid=AiFkdFjTpS7rgix1mH1Z1RKHJTp5ZJt6qZJdgeNzfHLato4xM
577!-47717630!-949856032!9001!-1

Copyright © 2004 Galen of Ockham, MC, OP (MKA Keith E. Brandt, M.D.)
May be used in SCA publications as long as content is not modified
and proper credit given. For all other uses, please contact the
author at galen at chirurgeon.org.

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Saint Phlip,
CoDoLDS

"When in doubt, heat it up and hit it with a hammer."
 Blacksmith's credo.

 If it walks like a duck, and quacks like a duck, it is probably not a
cat.

Never a horse that cain't be rode,
And never a rider who cain't be throwed....