Weightlifters, Bodybuilders, and Other Athletes Who Require Rapid Bursts of High-Energy

Weightlifters, bodybuilders, and other athletes who require rapid bursts of high-energy muscle output often spend a lot of money on dietary supplements. Some supplements, such as amino acids, are used by the body as building blocks to make more high-protein muscle cells. Other supplements increase energy or provide more endurance during workouts. For example, supplements that contain creatine (often sold as creatine monohydrate or creatine diphosphate) are reputed to provide more energy. Based on this information and your knowledge of muscle physiology, would you expect creatine supplements to provide extra energy? Why?

A) No, because creatine is not used for energy production in the body.
B) No, because the digestive system breaks down creatine, which is a large protein macromolecule, before it can be used by the body.
C) Yes, because creatine is used directly as a source of energy by muscle cells.
D) Yes, because the creatine supplement can donate phosphate ions to regenerate ATP.