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June 2002
Previous issues
This is a new addition to our website - Runner's Corner! Each month we'll offer a new article by Kitty Consolo, Ph.D. Kitty is a veteran runner and exercise physiologist. She has been running and racing since 1975, and has won over 400 road races ranging from the mile to the marathon and went to the first women's Olympic marathon trails in 1984. Kitty has a PR of 2:42.46 for the marathon and 35:02 for the 10km, She now enjoys shorter races and masters running.
Enjoy, and please let us know your thoughts about the Runner's Corner! ____________________________________________________________________
Safety Guidelines for Running in Hot Weather
Runner's Corner by Kitty Consolo, Ph.D.
Summer and hot weather will soon be approaching
and after our long unexpected cold spell in Ohio, no doubt many of us
will welcome running in the heat. However it takes a good two weeks
of consistent training in hot weather to become heat acclimatized and
even so, some conditions can cause heat illness even in the fitness of
runners. This months article will help prepare you to deal with the
heat, recognize signs of heat injury and minimize these problems.
Guidelines to
watch in regard to heat index.
If you have lived in Ohio for awhile, you will
know that our summers are not only accompanied by high temperatures,
but also high humidity as well. The combination of heat and humidity
can make for some very challenging running conditions and make the
heat index feel much higher than the air temperature alone. This is
because in order for the body to dissipate heat at high air
temperatures, it must rely on the evaporation of sweat, not sweating
alone. High humidity causes most of our sweat to roll off decreasing
the amount of heat we can dissipate. To get some idea as to the
weather conditions find out both the air temperature and humidity or
better yet, the heat index or apparent air temperature which takes
into account both. These are often given out on weather forecasts
which you can tune into easily by purchasing a weather radio (very
inexpensive) or tuning into the weather channel or weather.com and
logging in! the zip code you are in. The following are heat index
values that pose heat risks:
130 F degrees or higher Heatstroke/sunstroke likely
with continued exposure
105 F degress Sunstroke, heat cramps,
heat exhaustion likely and possible
with prolonged
exposure and/or physical activity
90-105 F degrees Sunstroke, heat cramps,
heat exhaustion possible with prolonged
exposure and/or
physical activity
80-90 F degrees Fatigue possible with
prolonged exposure and/or physical activity
Keep in mind that if you are not heat acclimatized,
are younger than 18 or older than 50 or obese, you can suffer heat
illness at even lower heat indexes.
Signs and Symptoms of Heat Injuries
Heat Injury
Causes Symptoms treatment
heat syncope blood pooling in skin
fainting, weakness, fatigue place in cool place, give cool fluid
heat cramps excessive loss of electrolyte
cramps rest in cold place, ingest fluids with electrolytes
salt-depletion heat exhaustion excessive loss of
electrolytes nausea rest in cool, give fluids only if
conscious
fatigue, fainting may
need medical help
water-depletion heat exhaustion too much sweat
loss fatigue, nausea cool pale skin, active sweating
rest in cold place and give water, cool body
may need medical help
heat stroke body core temp high
headache, vomiting
unconsciousness, core temperature above 105.8 cool body with
ice packs get medical help fast
Keep in mind that if you are starting to notice
fatigue or cramps, and you keep on exercising in the heat, that your
body can quickly progress to a state of heat stroke which can be life
threatening. If you are noticing fatigue and cramps and especially if
your skin is getting goose bumps, you are on your way to dehydration
and need to stop, get in a cool place and get fluids before getting
seriously ill.
Guidelines for Fluid/electrolyte Consumption
Related to Event
This chart should help you prepare better for your
event.
Event time
of consumption amount
less than 60 min Before:
1-2
hours 16 oz cold water
15-30
min 10 - 16 oz cold water
can have 6-8% carb drink
during:
every 10-15
min 6-8 ounces cold water
recovery:
next 24 hours drink
until back to pre-event weight
1-4 hour
even before
1-2
hours 16 oz 5-10% carbo drink
15-30
min 10-16 oz 5-10% carbo drink
during:
every 10-15
min 6-8 oz carb drink 5-10%
Recovery:
immediately after and every 2 hours 1
gram carbo per kg body weight
50-70 grams of carbohydrate and
some protein.
Keep in mind that you should test out any drink you
want to try during training to see if you tolerate it. It is
important that any drink that has carbohydrate be diluted to 10% or
less otherwise, it will keep the fluids from leaving your stomach and
you will get even more dehydrated. Some commercial drinks and their %
carb content are listed below:
gatorade thirst quencher 6%, sucrose & glucose in
powder, syrup added to liquid
powerAde 7.9%, high fructose
corn syrup, maltodextrin
All sport 8-9%, high fructose
corn syrup, maltodextrin
orange juice 11-15% Too High!;
fructose, sucrose
coca-cola 11% too High high
fructose corn syrup
Hydra fuel 7% glucose polymers
Also keep in mind if you have food allergies to corn
that many of these drinks use corn syrup. You can also make up your
own solution by just adding sugar to water and dilute to 5%.
Electrolytes and supplements
In the old days, it was thought that when one
sweated a lot, one needed to take salt tablets and potassium pills.
Many unnecessary deaths results because in reality, most of what is
lost in sweat is water and unless one has a crazy restricted diet, it
is easy to replace salt and potassium through our diet. In fact our
bodies work best by getting these minerals in food and high doses of
potassium can disturb the heart's rhythm and cause death!
One needs 2000 milligrams of potassium a day which
can easily be gotten through:
bananas 1 medium contains: 460 mg
baked potato 1 avg contains: 780 mg
1 stock broccoli contains: 270 mg
1 medium carrot contains: 275 mg
1 glass skim milk contains 410 mg
1 oz fish contains: 160 mg
We only need 500 mg of sodium, just check out the
sodium in salad dressings, potato chips, canned soups and soft drinks
and you will likely be getting much more than 500 mg per day.
How can I tell if I am dehydrated?
Unlike our canine companions, we humans do not
even feel thirsty until we become 1-2% dehydrated. That amount is
enough to cause fatigue, sore muscles and lead us to heat problems.
Best way to find out if you are dehydrated is to look at the color of
your urine. It should be clear or very light yellow, if darker, you
need more fluids. Also weigh yourself before and after a workout.
This is really the only time the scales are useful. Otherwise forget
about how much you weight as the scales do not tell you how much fat
and muscle you have. Any weight you have lost during a workout should
be put back on through drinking lots of water and juice, not caffeine
or alcohol. A simple formula for determining the water you need is:
take your body weight in pounds divide by half. This is the number of
ounces of water you need per day plus another 8 ounces for every 20
minutes you exercise! This is a lot! To help get the amount you
need, carry your own water container and know how many ounces it is,
then know how many you need to drink a day so that you can keep up
with your hydration. Staying hydrated will give you more energy, help
your muscles recover faster and prevent heat illness!
See you on the roads and stay cool!
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