The primary system that benefits from aerobic exercise is the cardiovascular system. Engaging in regular aerobic activities, such as running or cycling, strengthens the heart, enabling it to pump blood more efficiently. This increased efficiency helps improve oxygen delivery to tissues throughout the body. As a result, aerobic exercise can reduce the risk of heart disease, lower blood pressure, and improve cholesterol levels. Furthermore, it promotes better overall circulation and enhances the body's ability to endure physical activity over prolonged periods.