Saw an interesting paragraph on bodyandfitness.com in regards to carb loading:
Carbohydrates turns into glycogen in the body. Glycogen is stored in the muscle for fuel and the muscle needs fuel to grow. When you take away the glycogen (crabs) from the muscle (this is done with cutting crabs and adding high protein) the muscle, like anything else will get paranoid.
Now when you feed the muscle of something that it hasn’t had for a couple of days, the first thing it is going to do is take more then it needs to satisfy. This is called “carbo loading”.
Glycogen depletion followed by glycogen replenishment, which is also known as carbohydrate loading, causes the muscles to increase their water content considerably. When glycogen replenishment is complete, the increased body weight may induce the muscles to feel heavy and stiff.
When you have been training and dieting hard for a contest, your body will be glycogen depleted. The body is programmed to over compensate when there is a depletion. It will already be predisposed to store larger than normal amounts of glycogen that you ingest.
With proper diet manipulation, you can exaggerate this over compensation ever further by first restricting your carbohydrates intake. Normally, the body stores about 2 grams of glycogen for every 100 grams of muscle weight.
But when you become carbohydrate depleted and then take in carbohydrates it will then stored 4 to 5 grams of glycogen per every 100 grams of muscle weight. The results: BIGGER, HARDER, and more DEFINED MUSCLES. Because of the differences from one body to another, only generalizations can be made as to the amount of carbohydrates required to carb up.
A 200 pound bodybuilder could use 5,000 to 6,000 carbohydrate calories over a 3 day period in preparation for a contest. The body cannot absorb excessive amounts of carbohydrates at one time. An acceptable rate would be 100 calories of carbs per hour.
The body needs approximately 3 days to fully carb up. this means start on the 4th day before the contest. Eating an average of 100 calories of carbohydrates per hour over a 16 hour period will almost equal this amount.
Because you will be striving to lower your sodium intake, make sure these foods are free or low in salt content the 3 days before the contest. Because of the extra carbohydrates, you should be drinking approximately three times as much water by “weight” as you are taking in carbohydrates.
This flies into the face of some of what Thib was saying, as long as you keep the carb ingestion slow and don’t go crazy with it, sounds like muscles can store A LOT of glycogen. Drink your water!