Remember, there is no such
thing as an essential carbohydrate! Along with fats and proteins,
carbohydrates are an important souce of fuel for your body. In
terms of firt - line availability, carbohydrates supply the most
accessible and utilized energy source. Though the major player in
terms of hourly provision of energy substrates, carbohydrates
supply at best two percent of the total available human fuel
reserves. Fats contain the vast majority of the body's reserve
energy platform at 80 percent, with skeletal muscle filling in the
18 percent gap.
You store far less
carbohydrate energy than fat, but fats are second place when it
comes to stoking the furnace within. The explanation for so little
cabohydrate being stored involves the manner with which the body
holds carbs. A single gram of stored carbohydrate muscle glycogen
is maintained along with perhaps four grams of water. In terms of
evolution, it is better to carry your fuel reserves in as dense a
form as possible. Fats provide just this needed form of compact
energy reserve. Each gram of fat yields nine calories, while carbs
and protein provide four calories per gram.
So for every gram of
carbohydrate, you have to drag around five grams of material. In
the case of fats, they have a one - to - one ratio, with no excess
water associated with the scenario. Additionally, carbs burn at
four calories per gram and fats at a little over nine calories per
gram, so it becomes clear which storage strategy will allow greater
range of functional mobility for the evolving human. It is a matter
of evolution that our bodies use fats over carbs for survival. Non
dietary carbohydrate sources of energy include skeletal muscle
stores in the form of glycogen and blood glucose derived from the
liver (more exactly, synthesized from amino acids in the
liver).
Description of
Carbohydrates
In human nutrition,
carbohydrates are any of a group of organic compounds, the most
important being saccharides, starch, cellulose, and gym. Digestable
carbohydrates are classified as dietary carbohydrates and
indigestible are classified as dietary fiber or fibrous carbs. You
will often here the terms starchy and fibrous carbs.
Dietary carbohydrates fall under one of two categories: sugar or
complex.
Simple Sugars The
two principal categories of sugars are monosaccharides and
disaccharides. A monosaccharide is a simple sugar, such as glucose,
fructose, or galactose. A disaccharide is a double sugar, such as
sucrose (table sugar) or lactose.
Complex Carbs
Complex carbs, or polysaccharides, are carbohydrates that contain
three or more molecules of simple carbohydrates. Some examples of
polysaccharides are dextrins, starches, glycogens, celluloses,
gums, inulin, and pentose. Common souces for polysaccharides are
grain products, legumes, potatoes, and other vegetables.
Carbohydrate
Metabolism
Your carbohydrate
metabolism is the sum of the anabolic and catabolic processes of
the body involved in the synthesis and breakdown of carbohydrates.
These metabolic carb processes are: glycogenesis - the synthesis of
glycogen from glucose, glyconeogenesis - the formation of glycogen
from fatty acids and proteins rather than carbohydrates, and
glycolysis - the breakdown of glucose and other sugars.
The status of your
carbohydrate metabolism is based largely on the level of blood
glucose or circulating carbohydrates. This is, in turn, dictated by
the timing and frequency, along with the nutrient composition, of
your last meal. The time of day that finds most of our blood sugars
at their lowest level is early morning. Generally, upon
awakenening, you have undergone essentially a seven - to - nine
hour fast without any new supply of ingested substrate for the
needed maintenance of your blood glucose levels. (A blood sugar
range of 40 or more than 400 milligrams / deciliter is
acceptable).
The source of the fuel in
this potabsorbtive or fasting state is 75 percent glycogenolysis
and 25 percent gluconeogenesis. The process of blood sugar balance
is dynamic one, with the brain and functioning of the red blood
cells (or erythrocytes), for example, using glucose as a preferred
fuel source. The metabolites of imcomplete utilization of fatty
acids, ketones are able to serve as substitute fuels in the absense
of sufficient glucose, but only after a period of great metabolic
adjustment.
Note: Understanding
the subtle differences between medical terms that begin with the
same set of letters is very important for an effective bodybuilding
mind. Another very confusing aspect of this is refined terminology
is the different word forms that, though spelled differently, apply
equally to the same concept. An example is the gluco and
glyco which are equally correct forms for words such as the
following
(1)
Glycogenesis is the synthesis of glycogen from
glucose.
(b>(2)
Glycolysis is the process whereby glucose and other sugars
are broken down to produce fuel for energy.
(3) Glyconeogenesis is the formation of glucose
from non carbohydrate sources such as amino acids and fatty
acids.
Muscle and Insulin - Moving Carbohydrates Where You Need Them
Most
To understand insulin, we'll start with the pancreas. The
pancreas is a gland that secretes various substances, such as
digestive enzymes, insulin, and glucagon. It is a compound gland
composed of exocrine and endocrine tissue. About 1 million
endocrine cellular islets of islands of Langerhans are embedded
between the exocrine units of the pancreas. Beta cells of the
islands secrete insulin, which helps control carbohydrate
metabolism.
There are two aspects to defining insuling. First is the
interanlly synthesized or naturally occurring hormone secreted by
the beta cells of the islands of Langerhans in the pancreas. The
release of insulin is mandated by increased levels of glucose and
amino acids in the blood. Insulin serves to maintain the metabolism
of glucose along with intermediary metabolism of fats,
carbohydrates, and proteins. Insulin lowers blood glucose levels
and promotes transport and entry of glucose and amino acids into
the muscle cells and other tissues. Too little secretion of insulin
results in hyperglycemia (elevated blood sugar levels),
hyperlipemia (elevated blood lipids or fats), and ketonemia
(elevated blood ketones). Left uncorrected, severe insulin
deficiency is fatal.
Second is the commercially prepared pharmacologic product used
in diabetes. Several preparations of insulin are available, varying
in rapidity of onset, intensity, and duration of action. They are
termed rapid acting, intermediate acting, and long acting. Insulin
is largely given by subcutaneous injection.
The alpha cells of the islets secrete glucagon that balances the
action of insulin, and the acinar units of the pancreas secrete
digestive enzymes. The beta cells of the pancreas are insulin -
producing cells. The insulin - producing function of the beta cells
accelerates the movement of glucose, amino acids, and fatty acids
out of the blood and into the cellular arena, countering the
glucagon function of alpha cells.
Glucagon is the countermeasure opposing insulin. Produced in the
pancrease by alpha cells, glucagona functions to stimulate the
conversion of glycogen to glucose in the liver. This system of
energy conversion is built upon stored glycogen within the liver.
Secreation of glucagon is stimulated by hypoglycemia and by GH. A
pharmaceutical preparation of purified, crystallized glucagon is
used in the treatment of certain hypoglycemic states.
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