CARBOHYDRATES:
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!!