Which energy system dominates during events lasting 2–3 minutes?

Which energy system dominates during events lasting 2–3 minutes?

• A. Phosphagen system
• B. Oxidative metabolism alone
• C. Anaerobic glycolysis (lactate-producing) with contributions from oxidative metabolism
• D. Ketone oxidation

Answer: (C)

During events lasting around two to three minutes, the primary energy source is anaerobic glycolysis, with oxidative metabolism contributing. The phosphagen system dominates only in the very first seconds of activity and is largely depleted well before this duration, so it isn’t the main supplier at 2–3 minutes. Ketone oxidation isn’t the key fuel for these efforts either; ketones generally play a smaller role during higher-intensity, shorter-duration bouts and longer, steady-state activities rely more on oxidative metabolism. Anaerobic glycolysis rapidly generates ATP from glucose to meet the quick energy demands, and as the effort continues, oxidative phosphorylation increases its contribution to sustain ATP production. This combination explains why anaerobic glycolysis with some oxidative input best describes energy supply for 2–3 minute events.

During events lasting around two to three minutes, the primary energy source is anaerobic glycolysis, with oxidative metabolism contributing. The phosphagen system dominates only in the very first seconds of activity and is largely depleted well before this duration, so it isn’t the main supplier at 2–3 minutes. Ketone oxidation isn’t the key fuel for these efforts either; ketones generally play a smaller role during higher-intensity, shorter-duration bouts and longer, steady-state activities rely more on oxidative metabolism. Anaerobic glycolysis rapidly generates ATP from glucose to meet the quick energy demands, and as the effort continues, oxidative phosphorylation increases its contribution to sustain ATP production. This combination explains why anaerobic glycolysis with some oxidative input best describes energy supply for 2–3 minute events.