If your blood sugar drops, you are in BIG
trouble. Blood sugar is maintained from the carbohydrates that you eat,
and the liver can also release carbohydrate to maintain your essential
blood sugar levels. The carbohydrates you eat before, during, and after
exercise helps to maintain muscle and liver stores, and to maintain blood
glucose.
Before your race:
Endurance athletes should
typically consume a diet that contains 45%-65% of the total calories from
carbohydrate. A diet that is habitually high in carbohydrates helps to
ensure adequate liver, and muscle glycogen stores. Since high intensity
work such as a hard training session, or race requires mostly
carbohydrates (glycogen) for fuel, it makes sense that you would want
these stores of carbohydrate to be maximal. Dr Steven
Nizielski, currently at GVSU in
Minnesota once taught me in an exercise nutrition class at Texas A&M
University that diet patterns metabolism. This theory essentially says
that the body becomes more adept at using whatever fuel you provide it.
When you eat lots of carbohydrate your body becomes better at utilizing
carbohydrates... the fuel required to do high intensity exercise. In
study after study, athletes that consumed diets high in carbohydrate were
able to exercise longer and harder than athletes consuming diets
consisting primarily of fat and protein.
Carbohydrate loading: Some athletes
may want to carbohydrate load before extremely long and grueling events in
an attempt to increase muscle glycogen stores above normal levels. The
old method of carbohydrate loading involved performing a glycogen
depleting exercise( one that used up all of the stored carbohydrate in
your muscles) 7 days before the event, followed by 3 days on a low
carbohydrate diet, and finally 3 days of a high carbohydrate diet, and a
marked decrease in exercise volume. More recent research indicates that
this exhaustive protocol is unnecessary. An athlete can obtain the same
high muscle glycogen levels by simply following the typical high
carbohydrate diet, and reducing training to a short 10 –15 minute warm-up
in the 3 days preceding the event. Carbohydrate loading is not really
going to help you for a 45-90 minute criterium, but it may be to your
advantage to carbo load before a century ride, an ironman, or a 24 hour
race.
During your race: What do you have in
your water bottles?
During a race or training
sessions carbohydrates should be consumed in their simplest form
possible....sugar. Sugar in a fluid replacement beverage actually
helps intestinal absorption of water, and this is definitely a plus. The
ingested carbohydrate also helps to save both liver and/or muscle
glycogen, and for a while it can even supply your muscles with adequate
carbohydrate even when those muscle stores are gone. Remember we want to
keep these stores high, and keep them for as long as possible, because we
need that carbohydrate for intense exercise. In repeated studies, cyclists
who consumed carbohydrates during exercise had faster 40k TT times, could
ride longer at a given wattage, and had stronger finishing sprints than
those who consumed a non caloric placebo.
What is the best way to consume carbohydrate
during
exercise?
We have
already said that carbohydrate helps absorption of water. That alone is
reason enough to put you carbohydrate in your water bottle. Flavoring the
water in your bottle also makes it more palatable. Aka it makes it taste
better. If your water tastes better, you are more likely to drink it, and
stay properly hydrated. Just don’t put too much carbohydrate in your
bottle. Too much can actually slow the rate at which your stomach
empties.. This means you aren’t going to absorb the maximal amount of
water and carbohydrate possible, and your belly will feel full and
uncomfortable. Research indicates that concentrations around 6%-8% do not
slow gastric emptying. With these concentrations, you can obtain both
maximal fluid absorption, and maximal carbohydrate consumption. It
just so happens that Gatorade falls
within this concentration. This is not an accident.
The makers of Gatorade did their homework
when they were making there product, and they contribute substantially to
the body of knowledge concerning carbohydrate, and exercise nutrition in
general. The main point here is that more is not always better, and
too much carbohydrate can be detrimental. This is not to say that
Gatorade is the only acceptable sports drink out there. You can make your
own fluid replacement beverage from diluted juice, kool-aid, lemonade, or
whatever you like. The most important thing is that you like the taste.
The electrolytes in commercial sports drinks are usually not necessary for
exercise bouts under 4-5 hours, as you will get plenty of sodium in the
meal you eat when you get home. However, sodium is recommended for those
100 mile+ rides. Athletes participating in very long events such as
RAAM, Iditasport, or The Ironman should definitely consume sodium during their
events or they may be at risk for hyponatremia. (Very low salt levels)
Remember, even in these type of events, the salt does not have to come
from a sports drink. You can eat a few pretzels, or just simply put a
pinch of salt in your bottle full of lemonade.
The rate of gastric (stomach) emptying is the primary factor limiting the
amount of liquid you can digest. Most of us can down the better part of a
large water bottle in an hour. Could be more or less, depending on body
size) Drink to little, and you may not be performing at your best. Too
much and you will feel bloated, so use the amount I have given as a guide,
and see how you feel. You should be sure to drink early and often. We
have all heard that old saying, " Once you are thirsty, you are already
dehydrated." This is true, but another reason to drink early and often is
that a stomach that is half full empties faster than one that is totally
empty. So you can get more of that coveted sugar and water into your
blood by drinking early and often.
So what is the big picture?
In a nutshell: You should
drink sugar and water during all races and most training sessions. It
can be in the form of Gatorade, kool-aid, lemonade whatever. Just don't
make it too sweet. Drink early and often
During Training: You wouldn't do a
race with a piece of equipment you have never ridden before. That is one
reason the way you feed yourself during a training ride should be similar
to the way you feed yourself during a race. This is especially important
if you are doing long training sessions, or hard training sessions on
successive days. The carbohydrate you put in your bottle today, not only
helps you perform at your best today, but it helps keep those muscles full
of the fuel you need for that training ride tomorrow. Solid food eaten
during racing/training should also be high in carbs. Remember, those carbs
are what fuels all of that hard work. Some of my favorites are bananas,
rice krispie treats, or dried fruit. That snickers bar may really
satisfy, but it will slow down the emptying rate of your stomach, and will
rob blood from your legs to send it to your stomach.
After your race/training session:
After a hard race or
training session, your liver and muscle carbohydrate (glycogen) stores are
low. You want to replenish them as soon as possible so that you can do
your best in tomorrow’s time trial stage, or get the most out the next
day’s workout. Carbohydrate is most readily absorbed during the minutes
and hours immediately following your exercise session. The reason for
this is that during exercise, transporters become active that help to
bring carbohydrate into the cell. These transporters are still active
after you stop exercising, and help your muscles absorb the carbohydrate
from that post workout pasta. If your workout or race was extremely
intense and/or long, you should not only eat immediately after exercise,
but consume carbohydrate at 2 hour intervals for the next 4-6 hours to the
tune of 1-1.5grams of carbohydrate pre kg of body weight. This means that
after an extremely long, hard ride or race, a170lb/77kg rider should
consume around 350-450 calories in carbohydrate every 2 hours for the next
4-6 hours. This carbohydrate can be consumed as fruit, pasta, bread,
juice or whatever carbohydrate source you prefer.
You do lose salt from your blood when you sweat, but the typical American
diet has more than enough sodium. A little sauce on your post ride pasta
will do a great job of replacing the sodium you lost on your training
ride.
There is
increasing evidence to indicate that adding protein in a 4:1 carbohydrate:
protein ratio may further enhance glycogen (carbohydrate stores)
resynthesis. Endurox R4 is
one product that has this mixture. If you like the stuff go ahead and
drink it, but it is by no means the only way to attain this ratio. The
first thing I do when I get home from a ride is make a nice tall glass of
chocolate skim milk. It has low fat, high carbs, and comes very close to
that 4/1 ratio, it also tastes better and costs about 5 times less than
endurox.
So
far, I have concentrated on carbohydrates. Read on if you want to learn
about protein and fats.....
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