Which type of exercise primarily improves cardiovascular fitness?

Cardiovascular fitness is best improved through aerobic exercises, which are designed to increase heart rate and promote the efficiency of the cardiovascular system. These exercises involve sustained activities that elevate the heart rate over an extended period, typically performed at a moderate intensity. Activities like running, swimming, cycling, and dancing are common examples of aerobic exercises.

These exercises enhance the body's ability to utilize oxygen and improve endurance, making them particularly effective for strengthening the heart and lungs. In contrast, weight training primarily targets muscular strength and size without necessarily improving cardiovascular efficiency, while high-intensity interval training involves bursts of intense exercises followed by rest or low-intensity activity, which can benefit cardiovascular health but isn't classified strictly as aerobic. Plyometric exercises focus on explosive movements that develop power, but they also don’t primarily target cardiovascular fitness. Thus, aerobic exercises are paramount when seeking improvements in cardiovascular health.