The Glycolytic Pathway is most active during which duration?

• A. 14-120 seconds
• B. Over 2 minutes
• C. 1-10 seconds
• D. 30-60 seconds

Answer: (A)

Glycolysis provides ATP quickly for high‑intensity efforts that are too long for the phosphocreatine system but not long enough to rely mainly on aerobic metabolism. In this middle range, the body depends on glycolysis to sustain ATP production, with lactate often produced as a byproduct when oxygen delivery isn’t keeping up.

This window of roughly 15 seconds up to about 2 minutes is when glycolysis contributes the most ATP relative to other systems. Short bursts (about 1–10 seconds) depend mainly on the phosphagen system, while efforts lasting longer than about 2 minutes rely more on oxidative metabolism. The 14–120 second range matches the period where glycolysis is the primary energy source, making it the best fit.