New research shows how adipocytes, or fat cells, regulate the flow of fat in and out of the cells. Although excess fat is the bane of bodybuilders, fat does serve a few vital physiological functions in the body. For example, when the body is at rest, about 80 to 90 percent of the
energy required by cardiac and skeletal muscle comes from fat. The body has only limited storage space for carbohydrates in the form of liver and muscle glycogen.
In addition, glycogen is stored with 2.7 grams of water per gram of glycogen, whereas Tat is essentially water-free, so the body has a far greater capacity for fat storage.