This is a big issue. So many people, feel that cardio out performs weight lifting. Science is showing that this is not the case. Cardio does have its place, but the benefits from weight lifting and adding HIIT (this is now the new cardio) will allow you to build lean muscles and lose weight. Just doing one is not going to give you your best chance of developing a healthy body. Weight lifting provides more than lean muscles, it stresses your bones to keep them working to stay strong and not become brittle or allow you to have issues later in life. Weight lifting actually burns calories after the workout is done. Then add HIIT into your weekly routine and now you are getting a cardio workout in that does more than work endurance, but it also combines various movements that increases your calorie burn. An article in healthline discusses all of this and more. Go HERE to read.