Which of the Following Fuel Reserves Can Be Used by Skeletal

Question

Which of the following fuel reserves can be used by skeletal muscle?
A) Protein
B) Glycogen
C) Creatine phosphate
D) Fatty acids
E) All of the above

Accepted Answer

Skeletal muscle can use all of the above fuel reserves for energy production, although the relative contribution of each fuel source depends on the intensity and duration of the exercise. Protein is not a preferred energy source, but can be broken down into amino acids and converted to glucose if necessary. Glycogen is stored in muscle and liver, and can be rapidly converted to glucose for energy during high-intensity exercise. Creatine phosphate is a high-energy compound that can donate a phosphate group to regenerate ATP, providing a quick source of energy for short bursts of intense exercise. Fatty acids are a slower but more abundant source of energy, particularly during low- to moderate-intensity exercise, and are stored in adipose tissue and muscle.