Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

What substance builds up in muscle during anaerobic exercise?

1. Glucose

2. Lactic acid

3. Carbon dioxide

4. Creatine

The correct answer is: Lactic acid

During anaerobic exercise, the body relies heavily on energy systems that do not require oxygen. This process primarily uses stored energy sources, such as glucose, to generate adenosine triphosphate (ATP), the energy currency of the cell. When glucose is metabolized for energy without sufficient oxygen, it undergoes a process called anaerobic glycolysis. As a result of this metabolic pathway, one of the byproducts produced is lactic acid. This accumulation occurs because the body converts pyruvate (the end product of glycolysis) into lactic acid when oxygen levels are low. The presence of lactic acid in the muscles can lead to the sensation of fatigue and muscle soreness, which is often felt after intense, short-duration activities like sprinting or heavy weightlifting. While glucose is a source of energy for anaerobic metabolism, and carbon dioxide is produced as a waste byproduct of aerobic respiration, they do not specifically build up in the muscle in the same manner as lactic acid during anaerobic exercise. Creatine, on the other hand, is involved in the rapid production of ATP through the phosphagen energy system but does not accumulate in significant amounts during anaerobic activity. Hence, lactic acid is recognized as the significant compound