Cardio training improves our fitness and stimulates our heart, so it can pump more blood = oxygen into the body. Thus, cardio training helps keeping the heart healthy and strong, allowing more energy to everyday activities and other physical activity.
Cardio training is easy and a practical way of workout for those who are busy in everyday life, but still want to keep the body and heart in good shape. Cardio training is also very good in combination with strength training and other sports where the muscles are pushed to perform.