Cardio training is important to make your heart stronger. Cardiovascular exercise comprises of exercises which increase your heart and respiration rate. Thus anything from walking, running, riding a bike, on the elliptical, dancing, jumping rope, or taking the stairs, can be considered a cardio workout. Cardio exercises contribute greatly in keeping you healthy by increasing your stamina, keeping viral illnesses away, managing chronic conditions, boosting your mood, and strengthening your heart.
A word of caution though: cardio exercises target the heart, lungs, and circulatory system to make them stronger; but on its own it is not enough to ensure injury prevention, muscle gain, higher strength, better coordination, or better flexibility. You must create a well-rounded workout plan to ensure that all aspects of your physical fitness are targeted equally well. Also, cardio exercises have to be designed according to each individuals physical and medical conditions and health.