Cardio fitness refers to the ability of the heart and lungs to supply oxygen and energy to the body during physical activity. Improving cardio fitness can lead to numerous health benefits, including a stronger heart, improved circulation, and better lung function. It can also reduce the risk of chronic diseases such as heart disease, diabetes, and obesity. Common forms of cardio exercise include running, cycling, swimming, and brisk walking. Engaging in regular cardio exercise can help maintain a healthy weight, improve mood, and increase energy levels. A strong cardio fitness level is an important aspect of overall physical health.