Which energy system primarily fuels activities lasting 30 seconds to 2 minutes?

The energy system that primarily fuels activities lasting 30 seconds to 2 minutes is anaerobic glycolysis. This system is specifically designed to provide energy through the breakdown of carbohydrates in the absence of oxygen. During moderate to high-intensity physical activities, like a 400-meter sprint or a high-intensity interval, the body requires a quick supply of energy that exceeds the capacity of the aerobic system.

Anaerobic glycolysis produces energy at a faster rate than aerobic pathways but is limited by the build-up of lactic acid, which can contribute to fatigue. This system efficiently supports activities of shorter duration (from approximately 30 seconds up to around 2 minutes) where demands for energy are high, but the duration is not long enough to fully utilize the aerobic energy pathway.

In contrast, the aerobic system supports longer-duration activities, typically sustained for several minutes or more, as it relies on oxygen to generate energy. The ATP-CP system, also known as the phosphagen system, mainly fuels very short bursts of explosive activity, lasting about 10 seconds or less. The oxidative system, which uses oxygen to produce energy, is employed during prolonged, lower-intensity exercise, further demonstrating that anaerobic glycolysis is particularly suited to the distinct duration of