Yes!  Cardio exercise is important for calorie burning and many other reasons BUT a proper and efficient exercise plan includes cardio AND strength training (along with flexibility, balance training, and specific exercises to strengthen the core.)

 

If you are just doing cardio, then you will be burning calories and strengthening your cardiovascular system (which is good!) but you won’t be really changing your body composition by building more muscle. For that you need strength training!

 

The benefits of strength training are numerous, including increased :  muscle strength, balance, bone density, lean muscle mass, insulin sensitivity, metabolism, and cardio endurance—not to mention that strong, lean muscles simply look better!