What type of training is primarily used to improve cardiovascular fitness?

Aerobic training, such as running or cycling, is specifically designed to enhance cardiovascular fitness. This form of training engages large muscle groups in continuous, rhythmic movements, which increases heart rate and promotes better oxygen delivery throughout the body. The primary goal of aerobic training is to improve the efficiency of the cardiovascular system, including heart and lung function, which helps in sustaining prolonged physical activity.

In contrast, resistance training focuses on building muscle strength and endurance through weightlifting, which does not primarily aim to improve cardiovascular fitness. Plyometric training involves explosive movements intended to increase power and speed but does not emphasize cardiovascular endurance. Static stretching is mainly used for flexibility and does not significantly engage the cardiovascular system. Therefore, aerobic training stands out as the most effective approach for enhancing cardiovascular fitness.