Simple and Complex Carbs

Today we will build off the "Types of Carbs" post. We will go a little further into what these carbs are and how they effect the body.

Simple Carbohydrates: The Sugars

The principal monosaccharides that occur freely in foods and are not bought tightly to other food molecules are glucose and fructose. Glucose (dextrose) is found commonly in fruits, sweet corn, corn syrup, certain roots, and honey. Fructose (also called levulose and fruit sugar) is found together with glucose and sucrose in honey and fruit. While glucose has traditionally been frequently encountered dietary sugar, fructose is becoming more popular due to the discovery that it enters the blood stream slowly and does not cause a rapid rise or fall in blood sugar levels like glucose does.

      *Side note: Research on fructose has also determined that preferentially replaces glycogen stores           in the liver rather than glycogen stores in the muscles. This is important because the brain                  derives most its glucose supply from liver glycogen, which is especially low in the morning after        the previous evening's fast.

Complex Carbohydrates:

The two most important energy contributing polysaccharides are starch and glycogen. Processed polysaccharides include maltodextrins and "glucose polymers", which are shorter polymers of glucose, and are commonly used in many sports drinks because they dissolve easily in water. Starch and other polysaccharides are referred to as "complex carbs".

Starch occurs in various parts of plants and consists of long chains of glucose units. Starch is a major dietary energy source and is found in grains, roots, vegetables, pasta, breads, and legumes. When starch is eaten, it slowly digests and releases glucose molecules from the intestines into the blood stream at a slow steady rate. As discussed preciously, most simple sugars are quickly absorbed from the digestive system into the bloodstream. Quick absorption leads to high blood sugar levels and conversion to fat by the liver. This is one reason why individuals on a fat-reduction diet should minimize simple-sugar intake (Fruits are fine!). Additionally, individuals who participate in explosive, high intensity sports should minimize intake of simple carbohydrates and fats because they are primarily burning muscle glycogen for energy, not large amount of fatty acids that endurance athletes use for energy.

Types of Carbohydrates

There are several types of carbohydrates, some better than other carbohydrates are categorized as: 

• Monosaccharides (one-sugar molecules)
• Disaccharides (two-sugar molecules)
• Polysaccharides (three or more sugar molecules)

Monosaccharides and disaccharides are commonly called sugars, while polysaccharides are called complex carbohydrates.

• Monosaccharides: Glucose, fructose, sorbitol, galactose, mannitol, mannose
• Disaccharides: 
• Sucrose = glucose + fructose
• Maltose = glucose + glucose
• Lactose = glucose +galactose
• Polysaccharides: Starch, dextrin, cellulose, and glycogen, all which are made of chains of glucose 
• Fibers: Fibers are mainly the indigestible complex carbohydrates (polysaccharides) that make up the plant cell walls, including cellulose, hemicellulose, pectin, and a variety of gums, mucilages, and algal polysaccharides.

Later this week we will look deeper into simple carbs/ complex carbs and their effect on the body. 

Metabolism part 2 (Exercise and Metabolic Responses)

Exercise will stimulate a series of metabolic responses that affect the body's anatomy, physiology, and biochemical make-up.

Aerobic System Changes: (Cardiovascular Training)

Aerobic training greatly increases the body's functional capacity to transport and use oxygen and to burn fatty acids during exercise. Some of the major changes measured as a result of aerobic exercise include:

• Increased mitochondria density in slow twitch muscle fiber, which results in higher energy production from fatty acids. Maximum oxidative capacity develops in all fiber types.
• Higher aerobic capacity.
• Increase in trained muscle capacity to utilize and mobilize fat, resulting from higher amounts of fat metabolizing enzymes, and increased blood flow.
• Greater development of slow twitch muscle fibers.
• Increased myoglobin, which is an iron-protein compound in muscle which acts to store and transport oxygen in the muscles.

Anaerobic System Changes: (Weight Training)

Anaerobic training greatly increases the body's functional capacity for development of explosive strength and maximization of short term energy systems. Some of the major changes measured as a result of anaerobic exercise include: 

• Increased size and number of fast twitch muscle fibers.
• Increased tolerance to higher levels of blood lactate.
• Increases in enzymes involved in the anaerobic phase of glucose breakdown (glycolysis).
• Increased muscle resting levels of ATP, CP, creatine, and glycogen content.
• Increased growth hormone and testosterone levels after short bouts (45 to 75 minutes) of high intensity weight training. 

Metabolism part 1 (metabolic set point)

Here is a term that receives a lot of attention in the sport and training world. People have a misunderstanding on how metabolism really works. This post will be part 1 in our metabolism series. Today's subject is metabolic set point and how to increase your metabolism.

Metabolism is controlled by your metabolic set point. It was discovered during an extensive weight loss study that your body seeks to maintain a certain base rate of metabolism, which has come to be called your metabolic set point. This set point is controlled by your genetics and the environmental factors. But the great thing about this process is it can be raised. Researchers have demonstrated that you can change your metabolic set point through dietary means and physical activity.  

The metabolic set point is the average rate at which your metabolism runs, and will result in a body composition set point. People with a slow metabolism seem to store fat easily, while people with a fast metabolism seem to be able to eat and never get fat. Your metabolic set point can be influenced by the external environment (climate), nutrition, exercise, and other factors. Studies have demonstrated that when individuals go on a low calorie diet, the body's metabolic set point becomes lower to conserve energy. It actually resets itself to burn fewer calories, thereby conserving energy. Exercises tends to keep the metabolic rate up, and more aerobic exercise tends to cause the body to burn more fat for energy.