Hydrate or Die®
By Steve Isaac (aka Chief)
A previous article explained how to calculate and satisfy your
body's fuel needs for ultra events like the WaterTribe Challenge.
Hydration was covered but many details were left out. This article will
fill in the the missing information.
You can customize this article so estimates further down in the
article will be appropriate for your weight.
Enter your weight in pounds:
A person in good health requires up to 4 liters of water each day
just to carry out normal metabolism. This fluid is replaced by the fluids
we drink and the food we eat during the day. When extra energy is
required more water is consumed to produce that energy. In addition to
normal metabolism, your muscles produce 8 to 10 times more heat when they are
working hard than when at rest so you need to cool your machine. The body
will divert blood to the skin and produce sweat which evaporates and cools the
blood. Your core temperature remains stable at 98.6 degrees because your
skin temperature might be cooled to about 77 degrees. Everything is
stable and you perform at your best.
Until you get dehydrated. As sweat is produced your blood
becomes thicker and your heart has to beat faster to make up for it. Less
fuel and oxygen is available to your muscles. Your performance
suffers. If you don't replace the lost fluids soon, you will become
seriously ill. A loss of only 2% of your body weight is enough to cause
initial symptoms. A loss of 6-8% can cause death. Consider that a
180 pound man only needs to lose 1.6 liters of water to display symptoms of
Just recently a Minnesota Viking player died of heat stroke during
a practice session. Proper fluid and electrolyte replacement may have
prevented this tragedy. Don't let dehydration take its toll on you.
In his book titled Serious Cycling and High Tech Cycling, Dr.
Edmund Burke says,
"With vigorous exercise in hot or humid conditions, you can start
to feel the effects of dehydration in less than one hour. You'll start to feel
a decrease in your strength and energy. After two hours, you may start to feel
the more serious effects – headaches, cramps or nausea. In fact, dehydration is
a key factor in bonking, or hitting the wall. Eventually heatstroke and heat
exhaustion can set in."
But dehydration is only part of the problem for athletes working in
high heat and humidity. When the ambient temperature exceeds 95º F,
evaporation of sweat is the only cooling mechanism available to the body.
If, at the same time, ambient humidity exceeds 80 percent, the ability to
dissipate heat from evaporation declines. Sweat will continue to pour
from your skin but your core temperature will rise leading to serious heat
related illness which can be life threatening.
Heat and Dehydration Illness
Here are some interesting facts that impact how your body deals
with heat and exercise intensity.
You can easily loose 1 to 3 liters of sweat per hour on a hot
You can lose 1 to 2 grams of salt per liter of sweat.
Your body can only absorb about 1 liter of water per hour
Water and electrolytes (salts) must be kept in balance
Notice that it is easy to lose more water than you can replace
every hour. This is a fatal formula if you don't take steps to keep
everything in balance.
So let's examine what can happen if you don't keep your body
happy. Remember, 2.2 pounds = 1 liter of water.
Note all calculations round down to the nearest whole liter with a
minimum of 1 liter.
|Anyone starting an exercise program or taking part in a high
intensity athletic event should consult their doctor. This article does
not intend to give medical advice. It is also recommended that you get
first aid training from a professional source.
Slight Dehydration is when you have a net loss of water
equal to about 2% of your body weight. This can happen in about one
hour. (Based on your weight this is a net loss of
Symptoms: Decreased performance and endurance
Treatment: Drink more water and sports drinks and/or slow
Heat Cramps may begin when you have lost about 4% of your
body weight. One more hour for a total of two hours is all it
takes. (Your body's net loss of
Symptoms: Headaches, muscle cramps or spasms often when you
stop to rest
Treatment: Drink sports drinks to replace lost electrolytes
Heat Exhaustion is more severe and starts with about 6% net
weight loss of sweat. It only takes one more hour for a total of three
hours. This condition is dangerous and must be rectified
immediately. (Your body's net loss of
Symptoms: Malaise, headache, weakness, nausea, loss of
appetite, vomiting, dizziness when standing up or sitting down. Victim is
still sweating, normal mental state, and is coordinated. Core temp no
higher than 104ºF.
Treatment: Stop all exertion and move victim to a shady spot,
loosen restrictive clothing, administer sports drinks and water. Place
cold packs along neck, arm pits, chest wall, and groin but not directly against
the skin. Fan while splashing with water or soak in cool water until the
core temp is reduced to about 100ºF.
Heat Stroke occurs at about 7% weight loss of sweat.
Your body does not have enough water left for cooling and other
functions. You begin to shut down. Death is imminent. (Your
body's net loss of
Symptoms: Confusion, disorientation, bizarre behavior, may
appear intoxicated, seizers, coma, rapid heart rate, low blood pressure, rapid
respiration. Sweating may be present but often is not. Core
temp 105ºF or more.
Treatment: Cool the victim as quickly as possible, use ice,
cold packs, fanning, even immerse the victim in cool water if possible.
Administer saline solution if possible but vomiting or aspiration is a
risk. If necessary, use an IV if someone in the group is qualified and
has the equipment. Treat for shock. Evacuate the victim to a
Notice that heat stroke is a life threatening condition. If
you are in the wilderness and cannot get to a hospital, you must
restore fluid and electrolyte balance in addition to reducing the core
temperature. First priority is to cool the victim. Dowsing with
water and fanning is very effective. Ice or cold packs can also be
used. Don't actually put the victim in a cool stream or lake because they
may drown. Trying to administer fluids to a victim that is unconscious or
having seizures is dangerous due to the possibility of vomiting and
aspiration. Do what you can. Cooling the victim may help them
recover enough to drink. If not, use an IV if you have the knowledge and
equipment. If that isn't possible, administer the fluids in a very small
amount but at frequent intervals. Maybe using only an eye dropper.
The solution MUST contain electrolytes. You can make a saline
solution which contains 5-7 grams of salt ( about 1 teaspoon) per liter of
water. Don't use a sports drink unless you have nothing
else. Note that this is a much stronger solution than you
would normally use for hydration.
|During the 2001 WaterTribe Challenge I was in a sleep deprived
state which caused me to ignore my hydration needs. After several hours I
finally needed to urinate. Even in my sleep deprived state I recognized a
problem when my pathetically small amount of urine came out the color of maple
Tip: The color of your urine is one of the best
indicators of your hydration condition. Clear to pale yellow is
good. Dark yellow, orange, or even brown can indicate dehydration or a
serious medical problem. But certain vitamins can effect the color of
your urine. Take your supplements with your evening meal so you can use
your urine as a hydration signal during the day.
You should monitor how many times you have to urinate. Once
every couple of hours is about right. Check the color each time.
Hyponatremia or Over Hydration
The flip side of dehydration is hyponatremia which is a build up of
excess fluid in the brain and lungs that results from electrolyte depletion
along with drinking plenty of water. Usually it takes high exertion for a
period of four hours or longer when the athlete is drinking plenty of water but
not replenishing electrolytes that are excreted in the sweat. This
condition is often confused with dehydration because many of the symptoms are
similar. Treating the condition with plain water only exacerbates the
problem. Death is a very real possibility.
The symptoms are:
pink frothy sputum
Treat with sports drinks containing sodium and potassium.
Salt can be used or make a saline solution. You must get electrolytes
into the victim.
How to Determine Your Hydration Needs
Hydration needs are different for each person and for each
climate. It can be very difficult to determine these need just by sweat
or exertion. For example someone running an ultra marathon may be
sweating buckets but all the sweat is evaporated and their shirt is as dry as
the sand. On the other hand, a sea kayaker in Florida during August may
be cruising along without much effort but their shirt is wringing wet.
They are sweating but little to no evaporation is taking place. Or
consider a cross country skier in a very cold climate. The ambient
temperature cools their body, but they loose a lot of water through breathing
very dry air.
There is a very simple experiment you can use to determine your
hydration needs under any condition. You should do this a few times
during your training sessions so you begin to know your body and its response.
Select a training session that will last for one hour or more.
Weigh yourself buck naked and dry.
Go out and do your training session. You might want to get
Hydrate normally during your training session.
When your training session is over, strip off your sweat-soaked
clothing quickly, towel off, and weigh yourself.
Subtract your the new weight from your previous weight to see how
much water you lost.
Divide your weight loss by 2.2 to find out how many liters of sweat
Depending on your exercise level and the weather, you may end up
with a net loss of fluid even though you hydrated yourself during the
exercise. This is normal. Remember that you can sweat faster than
you can replace fluids. If you consumed about one liter per hour and you
still lost fluid, you are on the road to heat exhaustion or worse. It
depends on how long you plan to maintain that pace.
What can you do? Slow down. Cool down. Take a
break and rehydrate. Always, always, always rehydrate when you stop to
sleep or after a race. And one more "always:" Always maintain electrolyte
Recommendations From American College of Sports Medicine
Based on available evidence, the American College of Sports Medicine makes the
following general recommendations on the amount and composition of fluid that
should be ingested in preparation for, during, and after exercise or athletic
It is recommended that individuals consume a nutritionally balanced diet and
drink adequate fluids during the 24-hr period before an event, especially
during the period that includes the meal prior to exercise, to promote proper
hydration before exercise or competition.
It is recommended that individuals drink about 500 ml (about 17 ounces) of
fluid about 2 h before exercise to promote adequate hydration and allow time
for excretion of excess ingested water.
During exercise, athletes should start drinking early and at regular intervals
in an attempt to consume fluids at a rate sufficient to replace all the water
lost through sweating (i.e., body weight loss), or consume the maximal amount
that can be tolerated.
It is recommended that ingested fluids be cooler than ambient temperature
[between 15 degrees and 22 degrees C (59 degrees and 72 degrees F])] and
flavored to enhance palatability and promote fluid replacement. Fluids should
be readily available and served in containers that allow adequate volumes to be
ingested with ease and with minimal interruption of exercise.
Addition of proper amounts of carbohydrates and/or electrolytes to a fluid
replacement solution is recommended for exercise events of duration greater
than 1 h since it does not significantly impair water delivery to the body and
may enhance performance. During exercise lasting less than 1 h, there is little
evidence of physiological or physical performance differences between consuming
a carbohydrate-electrolyte drink and plain water.
During intense exercise lasting longer than 1 h, it is recommended that
carbohydrates be ingested at a rate of 30-60 g.h(-1) to maintain oxidation of
carbohydrates and delay fatigue. This rate of carbohydrate intake can be
achieved without compromising fluid delivery by drinking 600-1200 ml.h(-1) of
solutions containing 4%-8% carbohydrates (g.100 ml(-1)). The carbohydrates can
be sugars (glucose or sucrose) or starch (e.g., maltodextrin).
Inclusion of sodium (0.5-0.7 g. per liter of water) in the rehydration solution
ingested during exercise lasting longer than 1 h is recommended since it may be
advantageous in enhancing palatability, promoting fluid retention, and possibly
preventing hyponatremia in certain individuals who drink excessive quantities
of fluid. There is little physiological basis for the presence of sodium in an
oral rehydration solution for enhancing intestinal water absorption as long as
sodium is sufficiently available from the previous meal.
Let's See How Real Products Work
Let's examine four products to see if they meet criteria 6 and 7 of
the American College of Sports Medicine recommendations. The first
product will be our baseline product, Gatorade. This is selected as the
baseline because it was the first commercial sports drink and it can be
purchased just about anywhere. The second, ACCELERADE, is one of the
newest high tech sports drinks that uses the latest scientific evidence on
athletic performance. The third is three gel packets taken over a one
hour period with a liter of water. And the fourth is the EnduroCaps from
Hammer Nutrition for electrolyte replacement only.
Table entries are calories per liter or grams per liter or percent
of Minimum Daily Requirements (MDR).
|30 to 60 grams
|.5 to .7 gm
Note 1: The Hammer product does not meet the
recommendations for carbs, but the Endurolyte Capsules are not intended for
that purpose. Hammer nutrition also supplies gels and Sustained Energy
for that purpose.
Note 2: PowerGels supply some electrolytes but not
enough to meet the ACSM recommendations. I usually use PowerGels for an
energy boost and rely on my sports drinks for the electolytes.
Complex carbs are typically maltodextrin.
Electrolytes are typically a combination of sodium and
potassium. Hammer Endurolytes also contain calcium, magnesium, and
manganese along with vitamin B6.
BCAA is Branched Chain Amino Acids which are used by the body for
C% and E% are vitamins C and E with the percentage of Minimum Daily
Requirements (MDR). These vitamins are anti-oxidants which help reduce
the negative affects of high intensity exercise.
Know your body. Do the water loss experiment a few times
under various conditions.
Find a combination of products that works for you. If you
haven't considered these issues before, you can start with the ones in the
Set your watch to alarm each hour. Use the hourly alarm to do
a mental inventory of your hydration and fuel consumption.
If you get that horrible sloshing in your stomach, you are drinking
too much too fast. Slow down your pace and your drinking rate.
You should urinate every couple of hours. Check the color of
your urine especially if conditions are worse than normal or your exertion is
higher than normal.
Use a bladder system for plain water or water with Hammer Caps
dissolved into it.
If you drink a lot of sports drinks, you will reach a state where
you just cannot stand the taste anymore. The same goes for gels.
Always have plain water and regular food available. If you are in zone 2
and below, you can normally use a lot of regular food. In zone 3 and
above, it becomes difficult to supply your needs with regular food over a long
Be especially careful when your high intensity exertion exceeds the
one hour and four hour time frames. For example, an Elite class Crucible
type event. Ultra events lasting 24 to 72 hours require extreme precision
and experience. Multi day events like a WaterTribe expedition race should
be handled in zone 2 or below.
Get first aid training including heat related illness.
Products to Consider
There are numerous products on the market to provide fluid,
electrolytes, and energy. We all have different needs and palates so it
is up to you to select the products that work for you. The following list
is not intended as an endorsement and certainly is not
Hydrate or Die® is a registered trademark of CamelBak, a great source for
hydration systems. Their bladders are top notch. Their packs are
good and relatively cheap. When I'm training, I never put anything but
water into a bladder. As soon as you put a sports drink into one of these
bladders, you begin a science experiment that you may not be able to
control. However, for racing it might make sense to use one bladder for
water and another for a sports drink. After the race, toss any bladder
that you can't get totally clean. Another idea is to dissolve Hammer
electrolytes in a bladder so you always get the right balance of fluid and
electrolytes. The bladder will be easy to clean since no sugar is
contained in the capsules.
Nutrition -- Gels and electrolyte replacement capsules. Their
capsules contain a blend of several salts and minerals that are designed to be
used with plain water or added to your favorite sports drink to enhance the
electrolyte replacement process. These capsules appear to be better than
plain salt tablets. In fact, they may be a good way to make saline
instead of using plain salt. Hammer products are gaining wide spread use
among cyclists, triathletes, and adventure racers but they can be hard to
find. Even online they were out of stock as this article was
written. I have not tried them yet, but I plan to experiment soon.
Gatorade -- I
used Gatorade as an example in this article because their products are
ubiquitous, they are available in liquid or powder form, and they work.
There are other sports drinks on the market so choose one you like. The
great thing about Gatorade is that it does meet the criteria define by ACSM and
if you run out of your favorite drink, you can typically find Gatorade at a
7-11 or gas station and such. The 20 oz size is perfect for regulating
and tabulating your consumption in zones 3 and above.
Do not confuse sports drinks with so called energy drinks like Red
Bull. Stay away from faddish energy drinks.
Excellerade -- It has been shown that a ratio of 4 to 1 (carb to
protein) has certain beneficial effects beyond the scope of this article.
I use EnduroxR4 everyday after strenuous exercise. It works for me.
I just started using Accelerade and I have not made a final decision about its
effectiveness, but preliminary results are good. EnduroxR4 and
Excellerade are now available from GNC.
along with plain water are great energy boosters, but notice that they do not
meet the ACSM recommendations for electrolytes. However, if you use
Hammer Endurolytes along with PowerGels or HammerGels for energy, you get an
Editor's Note: PowerBar (PowerGels) has
recently introduced (7/2004) a new sports drink product. It looks very
promising but I haven't tried it yet.
Wilderness and Travel Medicine, by Eric A. Weiss, M.D. published by
Adventure Medical Kits. This is a great little book about wilderness
first aid. Adventure
Medical Kits are great too.
© 2001 Steve Isaac. All Rights Reserved.