Correct Response: D. Complex carbohydrates are readily absorbed and processed by the digestive system. Therefore, the energy released from complex carbohydrates is available to the athlete relatively soon after consumption. In addition, because complex carbohydrates are made of long chains of simple sugars, it takes the digestive system a while to process the entire molecule. This results in a more steady release of energy over a longer period of time. Both of these factors make complex carbohydrates a good source of energy for endurance athletes. Although the liver can convert excess carbohydrates into triglycerides that are then stored in fat cells (A), triglycerides are not as readily metabolized by the body as carbohydrates. Therefore, they are not the ideal source of energy for endurance athletes. Energy from complex carbohydrates can be released relatively quickly, rather than slowly, even though it may take the body a while to break down the complete molecule. In addition, it is possible to deplete stores of complex carbohydrates from muscles during intense exercise (B). One reason complex carbohydrates are more filling (C) is that they contain fiber, which cannot be digested by the human body. However, because the fiber component is not digested, it also means that the body is not gaining energy from its consumption, which is not an advantage for an endurance athlete.
