Advanced Subsidiary (AS) WJEC Physical Education (PE) Practice Test

This question tests understanding of energy production without oxygen during quick, high-intensity efforts. When you push hard for a short time, your body relies on anaerobic energy systems—the phosphagen system for very short bursts and anaerobic glycolysis for slightly longer efforts. These pathways don’t require oxygen, delivering energy quickly but tiring quickly due to metabolites like lactate building up. Anaerobic endurance is the capacity to sustain those high-intensity efforts before fatigue forces a drop in performance. That’s why it’s the best term here—it directly describes maintaining efforts without relying on oxygen. In contrast, VO2 max measures the maximum rate of oxygen use during intense activity and reflects aerobic power, not anaerobic work. Lactate threshold relates to the point where lactate starts to accumulate during increasing intensity, indicating when you shift more toward anaerobic metabolism, but not the ability to sustain work without oxygen itself. Aerobic capacity refers to the body's efficiency in using oxygen over longer, sustained activity.