The body adapts to endurance training through several physiological changes. Primarily, it enhances the efficiency of the cardiovascular system, leading to increased heart size and stroke volume, which allows the heart to pump more blood with each beat. Additionally, there’s an increase in the number of mitochondria within muscle cells, improving energy production. Blood flow improves to facilitate better oxygen delivery, while the body also becomes more efficient in using fat as a fuel source, contributing to better performance over prolonged exercise periods.