CSSD Practice Exam 2025 – Complete Study Resource

The correct answer, anaerobic glycolysis, is significant because it is the primary energy pathway that fuels high-intensity exercise lasting around 4 to 5 minutes, such as a 1500m run. During this time frame, the body requires quick energy to sustain performance, and anaerobic glycolysis efficiently breaks down glucose into pyruvate, producing ATP without the need for oxygen.

In this anaerobic process, glucose is metabolized to provide energy rapidly, but it also leads to the accumulation of lactate, which can contribute to muscle fatigue. This pathway is particularly important in a 1500m event, where the intensity is high, and the duration exceeds reliance on immediate energy stores like ATP and creatine phosphate, which are primarily utilized in shorter bursts of activity.

In contrast, aerobic metabolism, while vital for longer endurance events, does not kick in as the primary energy source until the exercise duration extends beyond about 5 minutes and at a lower intensity. The ATP/PC system, although crucial for very short, high-intensity efforts (lasting up to around 10 seconds), is too brief to sustain a 1500m event. Fat oxidation is even slower than aerobic metabolism and is primarily used during prolonged, lower-intensity exercises