Which energy system is used for activity longer than 2-3 minutes and requires oxygen?

Which energy system is used for activity longer than 2-3 minutes and requires oxygen?

• A. aerobic
• B. glycolysis
• C. anaerobic
• D. oxidative system

Answer: (D)

The energy system that fits activities lasting beyond a few minutes and requires oxygen is the oxidative (aerobic) system. This pathway uses oxygen to fully break down fuel sources—primarily carbohydrates and fats—through processes inside the mitochondria (Krebs cycle and electron transport chain) to produce ATP. It has the highest capacity, meaning it can sustain energy for long durations, though it starts up more slowly than the immediate and glycolytic systems. Because endurance efforts rely on a steady, long-lasting supply of ATP, the oxidative system becomes the primary source once the activity extends past about 2–3 minutes.

The energy system that fits activities lasting beyond a few minutes and requires oxygen is the oxidative (aerobic) system. This pathway uses oxygen to fully break down fuel sources—primarily carbohydrates and fats—through processes inside the mitochondria (Krebs cycle and electron transport chain) to produce ATP. It has the highest capacity, meaning it can sustain energy for long durations, though it starts up more slowly than the immediate and glycolytic systems. Because endurance efforts rely on a steady, long-lasting supply of ATP, the oxidative system becomes the primary source once the activity extends past about 2–3 minutes.