RULE #2: CARB-UP
Carbs are very important for packing on mass. They not only help drive up levels of the anabolic hormone insulin, but they also load your muscles with glycogen (the stored form of carbs), which is important for two major reasons.
First, glycogen keeps muscles big and full. Glycogen pulls water into muscle cells, which fills them up like water balloons. Second, muscle levels of glycogen are an important indicator of whether you have enough energy to build muscle or whether you need energy (by breaking down muscle protein) to fuel your body’s functions. When your muscles are full of glycogen, as happens during a high carb diet, your body has the energy needed to grow; when glycogen levels are low, the body breaks down muscle for use as fuel.
- See more at: http://www.flexonline.com/nutrition/10-rules-eating-mass?page=2#sthash.KWoKrGAV.dpuf