Cardio exercises, short for cardiovascular exercises, are activities that increase your heart rate and improve blood circulation. Common forms include running, cycling, swimming, and brisk walking. These exercises help strengthen the heart and lungs, making them more efficient at delivering oxygen to the body. Engaging in regular cardio workouts can lead to various health benefits, such as weight loss, improved mood, and reduced risk of chronic diseases like heart disease and diabetes. It's recommended to aim for at least 150 minutes of moderate-intensity cardio each week for optimal health.