Final answer:
In prolonged duration exercise, ATP is generated by Glycolysis, Krebs cycle, and Beta-oxidation. While these pathways contribute to ATP production, most ATP is created through oxidative phosphorylation.
Step-by-step explanation:
In prolonged duration exercise, ATP is generated by All of the above: Glycolysis, Krebs cycle (also known as the citric acid cycle), and Beta-oxidation. Initially, muscle glycogen is broken down to glucose that enters glycolysis, leading to the creation of pyruvate. In the presence of oxygen, pyruvate is utilized in the Krebs cycle to produce energy. When glycogen levels drop, the body shifts to fat metabolism through beta-oxidation to fuel aerobic pathways. However, it is important to note that most of the ATP during aerobic exercise is not generated directly from these metabolic pathways but rather from the process of oxidative phosphorylation, which includes electron transport and chemiosmosis.