The body system primarily affected by regular cardiovascular exercise is the cardiovascular system. Engaging in activities like running, swimming, or cycling strengthens the heart, enhancing its efficiency at pumping blood. Regular cardiovascular workouts increase the size and strength of the heart muscle, improve blood flow, and lower resting heart rate and blood pressure. This form of exercise helps prevent chronic diseases such as heart disease and stroke while also promoting better lung function. Enhanced circulation also contributes to improved overall endurance and stamina in daily activities.