Glucose
This supplies the body with energy during intensive activity such as training. Glucose is absorbed by the small intestine, then must be removed from the blood and transported inside each cell before it can be used as fuel. For this to happen the body must release a hormone called insulin, which directs each cell to absorb glucose from the blood. Once inside the cell glucose provides energy storage.

Glycogen storage is crucial for intensive workouts. If your glycogen levels are low, due to not eating enough you will not only feel tired quickly but will burn protein to supply the energy needed for training. However maintaining your glycogen level will decrease the amount of protein you burn for energy.

During the first 30-60 minutes after training muscles need to be replenished with glucose to rebuild muscle glycogen stores. If muscles are not supplied with glucose after training, protein in your body including muscle will be broken down into Amino Acids, which are then converted into glucose and is used in the recovery process.


Sucrose
Sucrose is found in table sugar. Sucrose is broken down into fructose and glucose. Sucrose raises blood glucose faster than fructose but slower than glucose. Consuming too much sucrose will raise insulin levels, as these levels increase more blood glucose is stored as fat rather than glucose.


Fructose
Fructose is usually the most common sugar in fruit, but its not the only one. Fruit contains various amounts of glucose and sucrose. Fructose is used in energy drinks because it does not increase insulin levels to the same degree as other sugars. Therefore fructose drinks can increase sweetness without increased insulin levels immediately before and during training. Maintaining proper fluid balance is important in maintaining normal muscle function and improving recovery.


Lactose
Lactose is found naturally in milk which is used in margarine and butter. Lactose stimulates a greater insulin release than fructose but less than sucrose.


Glycemic Index
Most athletes and trainers utilise high amounts of glycogen which can cause highs and lows and moods swings, if they are not reasonably accurate with their carbohydrate intake.

One way of reducing this problem is to use a Glycemic Index. A Glycemic Index refers to the rate of which carbohydrates are broken down into glucose. What you need to do is to identify carbohydrates with low Glycemic Indexes so that they are broken down slowly, so you have a nice gradual release of blood sugar. Sources would be yams, brown rice, wholemeal pasta and sweet potatoes.