Cardio machines are fitness devices designed to improve cardiovascular health and endurance. Common types include treadmills, ellipticals, and stationary bikes. These machines allow users to perform aerobic exercises, which help increase heart rate and burn calories. They often come with adjustable settings for speed, resistance, and incline to cater to different fitness levels. Using cardio machines can be an effective way to incorporate exercise into a daily routine. Many machines also feature built-in monitors that track metrics like time, distance, and calories burned, helping users stay motivated and monitor their progress.