Which energy system has the highest capacity for ATP production?

The ATP-CP system provides only about 3 ATP per phosphocreatine molecule and is exhausted within approximately 10 seconds, giving it the lowest capacity despite its high power output.

Rapid (anaerobic) glycolysis yields only 2 net ATP per glucose molecule and is limited by lactate accumulation, restricting both its capacity and duration.

Slow glycolysis feeds into the oxidative pathway but does not independently generate ATP at a level comparable to the complete oxidative phosphorylation process.

Oxidative phosphorylation occurs in the mitochondria and fully metabolizes glucose and fatty acids using oxygen, yielding approximately 36-38 ATP per glucose molecule. This output far exceeds that of any other energy system. Its high capacity makes it the dominant pathway during prolonged, submaximal exercise.