Which of the following is an example of a cardiovascular exercise?

Running is classified as a cardiovascular exercise because it primarily focuses on increasing the heart rate and improving the efficiency of the cardiovascular system. This type of exercise enhances the ability of the heart and lungs to supply oxygen-rich blood to the muscles during prolonged physical activity.

In contrast, weightlifting typically emphasizes building muscular strength and does not primarily target cardiovascular endurance. Yoga and Pilates, while they can improve flexibility and core strength, also do not exert a significant enough influence on the heart rate for them to be considered cardiovascular exercises. They typically integrate elements of strength, balance, and flexibility rather than sustained aerobic effort. Thus, running stands out as an effective means to engage in cardiovascular conditioning.