Carbohydrates, fats, and protein, are the three
nutrients that supply your body with energy. There are many other
nutrients( vitamins, minerals, etc) that are required for life and good health,
but only these three are broken down for energy. Under normal and
exercising conditions, fats and carbohydrates provide almost all energy your
body uses. Protein does supply a small amount of energy under most
circumstances, but carbs and fats are by far
responsible for most energy metabolism.
One of the most important concepts concerning exercise and nutrition is that
carbohydrate (also known as starch, sugar, carbs, glucose) fuels high intensity exercise,
such as bike racing. Let me say that again! Carbohydrate fuels
high intensity exercise. While fat is capable of storing more
energy, this energy cannot be released as quickly as energy from
carbohydrate. As you exercise more intensely, energy needs to be released
at a faster and faster rate, therefore a greater percentage of energy is derived
from carbohydrate. For example: When you are sitting on your Lazy
Boy, watching Survivor, a little more than half of the energy you
are expending is coming from fat, and a little less than half is coming from
carbohydrate. If you get up and take your dog for walk, it
will change to about 40% fat and 60% carbohydrate. If you are on your
bike doing a 10 mile time trial, almost all of the energy you are using come
from carbohydrate! This is one of the major flaws of reduced carb diets
such as Atkins or the Zone. They do not include enough of the
carbohydrates that are absolutely necessary for high intensity exercise.
Both carbohydrate and fat can be stored. We have all observed fat can be
stored in essentially unlimited amounts (good for the caveman who may not eat
for a few days, until he kills another saber toothed tiger....bad for the average
American who has a McDonald's' on
every corner). Carbohydrates however, can only be stored in limited
amounts in the liver and your muscles, with a very small but very
essential amount stored in your blood ( aka: blood glucose).
If you overeat, carbs and protein can turn in to fat, but our ability to make
carbohydrates from proteins and fats is very limited. This is why it is important that
athletes eat a diet high in carbohydrates. next...
|
