Which of the following is a common exercise to improve cardiovascular fitness?

Improving cardiovascular fitness primarily involves activities that elevate the heart rate and enhance the efficiency of the cardiovascular system. Running, cycling, and swimming are all aerobic exercises that significantly engage large muscle groups and require sustained effort, which is essential for developing cardiovascular endurance. These activities promote increased heart rate, improved lung capacity, and better blood circulation.

In contrast, while yoga and Pilates can offer numerous health benefits, including improved flexibility and core strength, they typically do not elevate the heart rate to the same extent as running, cycling, or swimming. They may contribute to overall fitness and stress reduction, but they are not classified primarily as cardiovascular exercises. Weight lifting, on the other hand, primarily focuses on strength training and muscle growth rather than enhancing cardiovascular capacity, as it usually involves shorter bursts of effort with rest in between.

Therefore, the activities of running, cycling, and swimming are recognized as effective methods for improving cardiovascular fitness, making this choice the most suitable for the question.