Archive for the ‘Catabolic’ Category

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Carbohydrates (Carbs) are the primary source of energy for all body functions and muscular exertion.  Carbohydrates are the chief source of fuel for anaerobic activity (weight training, activities which raise heart rate above 60-70%).  It’s widely believed that in the absence of carbohydrates that the body will use fat for its fuel source.  While that is true, remember, only if you’re performing activity at a fat burning heart rate (aerobic- up to 60-65% VO2 Max).  Since carbs are our chief source of fuel, this leads to depletion of available and stored carbohydrates (glycogen) and creates a continual craving for this macronutrient.  Carbohydrates also help regulate the digestion and utilization of proteins and fats.

**Note: I intentionally refrain from using the term “cardio” in reference to lower intensity activity that targets body fat as a fuel source (as it’s so often used out of context).  I opt to use the term “aerobic” because by definition the word means simply, “with oxygen” or to oxidize fat for energy!  Whereas, cardiovascular activity is intended to train just that, cardiac tissues (of the heart), while this type of exercise is an absolute necessity for health, it’s not the focus of this particular article.  

**The depletion of stored carbohydrates (glycogen) does NOT occur within one workout or activity for the majority of individuals.  Mainly because the amount of glycogen the body can store is a relatively large amount.  The above statement in the first paragraph relating to this is made with individuals whom are consuming a restricted carbohydrate nutrition program, and are beginning their training sessions in a state of “carb depletion.”  Also, a state of depletion is relative, or at least dependent upon the type of activity being performed (e.g., long distance hike vs 45 min. weight training session).  Based on feedback from what you, the readers following this blog want, this article is intended to target those trying to reduce body fat levels and positively improve body composition.  I felt it necessary to clarify before continuing :))! 

The principle carbohydrates present in foods occur in the form of simple sugars, starches and cellulose.  Simple sugars, such as those in honey and fruits, are easily digested.  Double sugars, such as table sugar, require some digestive action but they are not nearly as complex as starches, such as those found in whole grains, rice and potatoes.

Starches require prolonged enzymatic action in order to be broken down into simple sugars (i.e., glucose) for utilization.  Cellulose, commonly found in the skins of fruits and vegetables, is largely indigestible by humans, but does play more then one very important role within the body.  The indigestible “roughage” is essentially just fiber(s), soluble and insoluble, fiber provides bulk for proper intestinal function and aides elimination.  Fiber is necessary for a number of other essential functions in the body, which I’ve discussed in previous articles.

All sugars and starches are converted by the body into simple sugars such as glucose or fructose.  All sugars must become glucose before the body can use them for energy.  Some glucose or “blood sugar” is used as fuel by tissues of the brain, nervous system and muscles.  A small amount of the glucose is converted to glycogen and stored in the liver and muscles, any excess is converted to fat and stored throughout the body as a reserve energy source.  When total calorie intake exceeds output any extra carbohydrate, fat or protein is stored as body fat.

Carbohydrate “snacks” (Ugh, I can’t stand that term!) which contain large amounts of refined sugars and starches, typically promote a sudden rise in blood sugar levels, thereby providing the body with an immediate source of energy and few nutrients.  The “insulin spike” which shortly follows this reaction rapidly lowers the blood sugar levels resulting in uncontrollable cravings for more sugary foods and potentially causing fatigue, dizziness, nervousness and headaches (varying levels of hypoglycemia).

Diets (Lifestyles) that are high in refined carbs are usually low in vitamins, minerals and cellulose.  Foods such as white flour, white sugar, instant potatoes, etc. are lacking in B vitamins specifically, as well as other nutrients.  Overindulging in starchy and/or sweet foods gives you calories without the nutrients and robs you of the essential nutrients to metabolize these foods.  **I realize this really isn’t ground breaking new information for most of you, but so often the basics of the basics are overlooked or at best assumed to be understood.  For some it may be very well understood, however, it’s the others (the majority) that this article is targeting…this is not meant to be a criticism to anyone what so ever, I myself need regular reminders to stop overanalyzing and get back to the basics!  I hope this can be that reminder for some of you!!

Glutamine & Creatine

Glutamine: The benefits may surprise you!

Glutamine is a common supplement found in many supplement stores, gym bags, protein shakes and a plethora of other nutritional products.  Yet, ironically it’s considered a non-essential amino acid…and in my opinion, the greatest benefits of glutamine rarely get recognized!  This is a disservice to all of you, hence the goal of this article is not to change anyone’s opinion or sell you on a glutamine product.  The goal is simply to teach you, to the best of my abilities, why glutamine is widely considered a staple in many training athletes supplement arsenal.  As well as, why glutamine should have more universal appeal to those outside the “bodybuilding/fitness” arena.

What is Glutamine?
Glutamine is classified as a non-essential amino acid, since it can be readily synthesized by various tissues such as skeletal muscles, liver, and adipose tissue.  glutamine is the most abundant single amino acid found in the bloodstream, which comprises 61% of the free intracellular amino acid pool (most abundant amino acid in skeletal muscle tissue), while Branched Chain Amino Acids (BCAA‘s) comprise 8.4% of the pool.  Glutamine’s unique structure, containing two nitrogen side chains, consists of 19% nitrogen- making it the primary transporter of nitrogen into the muscle cells.

Over the years people begun to recognize the benefits of glutamine (each will be discussed further), such as:
1) Enhances the Immune System
2) Enhances glycogen storage
3) Improves Intestinal and Gastric health
4) Prevents Muscle Tissue breakdown (Catabolism)
5) Promotes Muscle Tissue growth and repair (Anabolism)

What Does Glutamine Do?
During exercise or other times of metabolic stress such as diet, severe injury, illness, etc. the demand for glutamine in your blood matrix (Plasma) markedly increases.  For instance, various cells of the immune system such as lymphocytes and macrophages depend on glutamine as a primary fuel source, and thus the demand for glutamine increases when and immunological response is mounted.  Macrophages and lymphocytes are the primary virus and bacteria fighter in your bloodstream.  As glutamine travels through the body, the enterocytes of the small intestines are the largest consumers of glutamine accounting for about 40-50% of glutamine consumption.  Also, glutamine is required for the synthesis of nucleotides.  Thus, a sufficient supply of glutamine is particularly important for rapidly dividing cells such as enterocytes and the immune cells.  Therefore, the synthesis of glutamine may be insufficient to meet the physiological demand during times of severe metabolic stress when the amount of free glutamine is rapidly depleted.  Therefore, it may be beneficial for people who continuously place themselves in infectious areas or commonly get sick, to supplement with glutamine to aide virus and/or bacteria fighting cells.

Glutamine supplementation may also promote nitrogen retention (a positive nitrogen balance) and prevent the loss of muscle protein.  A decreased ratio of testosterone to cortisol is believed to be directly responsible for losses in muscle mass since cortisol promotes the synthesis of glutamine.  By maintaining intracellular concentrations of glutamine within the skeletal muscles, the synthesis of glutamine may prevent the loss of intracellular nitrogen.

Therefore, it may be beneficial for people who continuously place themselves through strenuous workouts to supplement with glutamine to aide when glutamine stores are depleted.  Furthermore, by enhancing plasma concentrations of glutamine, the demand for free form glutamine by other tissues and cells (i.e., small intestines and immune cells) is attenuated and thus the release of glutamine from muscle tissues is reduced.

Why Does Your Body Need Glutamine?
To fully understand why glutamine is beneficial to the body, we must continue this biochemistry lesson.  The body uses glutamine to shuttle ammonia around in the body, so blood levels of glutamine try to maintain constant.  Glutamine is craved by the digestive tract and the immune system as fuel.  Most people eat more than enough protein from the supermarket, but they do not get enough glutamine through the digestion of meats and other proteins.  Under certain pathological circumstances the body’s tissues need more glutamine than the overall amount supplied by the diet and natural synthesis such as during a strenuous workout.

During catabolic stress, for instance, intracellular glutamine levels can drop more than 50% and plasma concentrations can fall by 30%.  It’s under these circumstances that supplemental glutamine becomes necessary.

Skeletal muscle contains the greatest intracellular concentrations of glutamine, comprising up to 60% of total body glutamine stores, and is considered the primary storage depot of glutamine, and thus the primary exporter of glutamine to other tissues.  In times of metabolic stress, glutamine is released into circulation, where it is transported to the tissue(s) in need.  Intracellular skeletal muscle glutamine concentration is affected by various assaults including injury, sepsis, prolonged stress, and starvation.  Besides skeletal muscle, the lungs are the next largest producer of glutamine.
Glutamine is especially useful post workout when nutrients are at a low until recovery.  In this condition research shows glutamine levels are significantly reduced, taking up to one month (in extreme cases) to return to baseline.  In athletes, glutamine has been used as a marker to indicate overtraining.  This fall in glutamine is catabolic to muscle tissue.  In a catabolic state, glutamine is the first amino acid used to correct that deficiency.  Glutamine drives protein into the muscle cells where it is synthesized for growth  This means that additional glutamine is necessary during periods of stress, resulting in bigger, stronger muscle cells.

Research Findings
In a recent study of glutamine’s role enhancing the immune system, glutamine demonstrated that increased levels of glutamine leads to greater amounts of virus and infection fighting cells, T and B Lymphocytes.  Cells of the immune system including the macrophages and lymphocytes depend on glutamine as a primary fuel source.  In addition, it has been hypothesized that a high rate of glutamine consumption by these rapidly proliferation cells is required for sufficient nucleotide synthesis.

Research indicates that low levels of glutamine within the body may result in the increased susceptibility to infections and illness due to a suppressed immune system.  The ability to reproduce and the activity of immune cells in vitro have reportedly been suppressed in trials lacking glutamine.  Tests also demonstrated that the increased rate of infection and illness (particularly infections of the upper respiratory tract) has been reported among athletes participating in intense, long duration sports (i.e., marathon racing).
It has been suggested that a decline in plasma glutamine concentrations may be one of the factors responsible for this increased rate of illness.  Specifically, the activity of natural killer cells, a reduced number and proliferate ability of lymphocytes, and a reduced ratio of T-helper to T-suppressor cells may be the result of prolonged, exhaustive exercise.

Glutamine as a GDA (Glucose Disposal Agent)
In another study of glutamine’s role on glucose and glycogen formation, the importance of glutamine was also emphasized.  The human carbon based skeleton of glutamine can serve as a gluconeogenic precursor and may regulate gluconeogenesis, which is basically the production of glycogen, independently of the insulin/glucagon ratios.  Because glutamine may serve as a precursor to glucose independently of glucagon regulation, glutamine supplementation may also enhance glycogenolysis and thus increase muscle glycogen stores even when insulin levels are low.  So basically glutamine helps regulate glycogen in your body when levels are low and may even increase them, which would result in better performance and growth.

Use of Glutamine
Glutamine and L-Glutamine can be purchased in powder or capsule form.  Glutamine containing products are protein shakes, protein powders and protein drinks.  Additional glutamine can be added to protein powders and shakes.  However, glutamine is relatively unstable in solution, and thus glutamine powders must be consumed shortly after being mixed into solution.

Glutamine Side Effects
It is completely safe.  There are no known side effects.

Hopefully this article has opened you up to the topic of glutamine supplementation.  Supplementing with glutamine can result in measurable gains in strength, muscularity, and immune function.  Taking glutamine before and during a workout will increase performance and delay fatigue.  This amino acid is needed for the maintenance of muscle tissue during physical stress and intense exercise and plays a crucial role in the fight against sickness.  From the perspective of athletes, glutamine functions as an anabolic/anti-catabolic agent, which allows the body to burn fat and not muscle.  Therefore, glutamine is crucial in your quest to achieve Ultimate Human Performance!!

Human Energy Systems & Metabolism.