Which system primarily provides energy during high-intensity exercise?

During high-intensity exercise, the body primarily relies on anaerobic glycolysis to provide energy. This system functions without the need for oxygen and is capable of rapidly breaking down glucose to produce ATP (adenosine triphosphate), which is the energy currency of the cell. Anaerobic glycolysis is particularly effective during short bursts of intense activity, such as sprinting or heavy lifting, where quick energy release is essential.

In contrast, aerobic systems, like aerobic glycolysis and aerobic lipolysis, take longer to kick in and are more suited for sustained, lower-intensity activities where oxygen can be utilized effectively. The ATP-CP system, while it provides immediate energy, has a very short duration of effectiveness (around 10 seconds) and is primarily used in extremely short, explosive efforts rather than prolonged high-intensity exercise. Therefore, anaerobic glycolysis stands out as the primary energy system for high-intensity efforts lasting just up to a couple of minutes, making it the correct answer for this question.