Carbohydrates

There are different types of carbohydrate and each type is treated differently by our bodies. For example, glucose and bran are both carbohydrates, but they are on different ends of the energy spectrum. Glucose enters the bloodstream quickly and initiates a high insulin response, while bran never makes it into the bloodstream because of it's indigestibility. It mediates the insulin response by slowing the rate that other energy sources enter the bloodtsream at.

So what does this mean for athletes?

It means that athletes should carefully consider which type of carbohydrate to fuel up. Glucose is the main source of fuel for muscular activity, so when glucose runs out, the athlete stops performing. Therefore, understanding how to prevent glucose from depleting should be the main focus of an athletes nutrition practice.

As stated before, they are different types of carbohydrates and they are split up into 2 categories.....simple and complex. (there is actually another category containing mannitol, sorbitol etc... which is the stuff found in sugar free chewing gum, but it's not so important for this topic).

Anyways...

Simple carbohydrates (sugars) are split up into the following...

Monosaccharides (single molecule carbs) - Glucose (also known as dextrose), fructose and galactose.

Disaccharides (two molecules) - sucrose, Lactose and Maltose.

Complex are split up into the following...

Oligosaccharides (3-20 molecules) - maltodextrins for example

Digestible polysaccharides (20 plus - molecule starch carbohydrate) - these complex carbohydrates should provide the main source of carbohydrate energy

Indigestible polysaccharides (20 plus molecule non starch carbohydrate) - these types of carbs provide fiber.


Now that complicated stuff is out of the way...

It's not really essential for any of you guys to know that stuff, it's just best that i cover it anyway.

So where do all the carbs go?

Humans can store somewhere in the region of 350grams in the form of muscle glycogen, and additional 90g in the liver and around 5g circulates in the blood. The larger the muscle mass, the greater storage capacity, but also the greater the potential need.

Once all glycogen replenishment is complete, excess carbohydrate may be transported to fat/muscle cells where it will be stored as fat.

Glycogen stores and replenishment

Sports nutrionists recommend that regular exercisers consume a diet which is relatively high in carbs and low in fat. This recommendation is based on the fact that carbohydrate is very important for endurance exercise since carbohydrate stores - as muscle and liver glycogen - are limited. Depletion of these stores results in fatigue and reduced performance. Think of a car that runs out of petrol/gas.

This is why pre-exercise glycogen stores need to be full. This is why you see boxers load up on carbs before a fight.