Mark Greenwood
All I know about nutrition is what I've read for my own purposes, so
somebody correct me if my thoughts on this matter are flawed.
I thought the issue with these "huge insulin response" theories is that
they are all based on what the "average person's" body does. I was
under the impression that someone who does a significant amount of
athletic activity every day tends to metabolize the carbs more or less
immediately and does not exhibit this sharp insulin response to nearly
the extent that a sedentary person does. The insulin spike in sedentary
people is (as I understood it) a mechanism to deal with the fact that
they are consuming excess carbs that their body does not routinely
utilize in the near future. Athlete's bodies on the other hand have
been trained to expect to burn off those carbs as fuel and so their body
isn't as anxious to lower the blood sugar level the way a normally
sedentary person would. Of course, eating pure refined sugar is still
not the thing to do and what you want is complex, unrefined carbs that
your body consumes over a longer period... eating a couple of candy bars
is still probably going to yank your blood sugar level all over the map,
no matter how active you are.
Am I way off-base here? Is there a doctor / nutrition expert in the
house? Just what I have heard is that it's really hard to take these
studies that are done on the "average person" and apply them to very
athletic people because there's such a wide variation in the body's
responses due to training. Of course, it's equally specious to apply
studies done solely on Olympic athletes to most of the population...
Renata Hahn wrote:
I'm no expert, but I'v been reading a lot of books, many contradicting
each other. Dr. Phillip Maffetone would say you are eating way too many
carbs, and your system produces a huge insulin release in the blood
stream, thus causing all your blood sugar to be stored and go too low.
Then your body craves more carbos and sweets....you get very hungry
because your blood sugar has dipped too low. If you have been eating
lots of carbos, your body is used to getting more and more. Take that
away, it craves more. His solution, more protein and fat. He sais eating
too many carbos can prevent a higher percentage of fats from being used
for energy, and lead to an increase in body-fat storage and greatly
diminish performance.
After attending the OBRA convention and listening to the discussion on
nutrition,with Burke and others, I bought Suzanne Girards book,
"Endurance Sports Nutrition". She suggests eating a training diet based
on 3-4gms of carbohydrate per pound of body weight. She goes further
into detail based on how many hours you train. 1 hr, 3grams,
2hrs-4grams, 3hrs-5grams (all per pound of body weight, yes, 60% of
total calories) Protein, 0.55-0.75 grams per pound. (15-20%). Fat, 0.5g
per pound (at least 20%). Then up that 3-4 days prior to an event to
4-5grams of carbos per pound for three days.
You need the Fat to optimize your body to burn it, it's a concentrated
sourceof energy, it releases 9 cal/gram (carbos only 4cals/gram). You
need to train your muscles to burn fat and spare glycogen (stored
carbos) during exercise. Metabolizing fat and carbos requires different
sets of enzymes. Highly trained endurance athletes can use more fat and
less glycogen at the same intensity level as less fit athletes. (Since
you rely on fat as an energy source during long bouts of exercise)
Protein is needed to rebuild muscle tissue, and replace the amino acids
oxidized during exercise. Also during long bouts of exercise," when
glycogen stores run low, protein is used as fuel, and may contribute as
much as 15 % of the energy needed". (from Suzanne's book). So you need
protein to maintain lean muscle tissue, not to break it down as fuel.
Especially after exercise, you need to eat protein and carbos 15-30
minutes after, to rebuild muscle proteins and replenish glycogen stores.
So, the 60-65% carbos, 15-20% protein, 20% fat seems to be the optimal
agreed upon amount. Good luck..
Renata