Which physical fitness component involves the heart and lungs' ability to supply oxygen during sustained physical activity?

The component of physical fitness that involves the heart and lungs' ability to supply oxygen during sustained physical activity is cardiovascular endurance. This aspect of fitness is crucial for sustaining prolonged exercise and is primarily influenced by the efficiency of the cardiovascular and respiratory systems. When a person engages in activities like running, cycling, or swimming, the body requires a steady supply of oxygen to the working muscles. Cardiovascular endurance enhances this ability, allowing individuals to perform at higher intensities and for longer durations without fatigue. Improved cardiovascular endurance can also lead to better overall health outcomes, such as lower resting heart rates, improved circulation, and increased aerobic capacity.