Cardio does NOT...
...burn fat or improve the health of your heart more than other forms of exercise.
What other forms?
There are some people who think that resistance train needs to be accompanied by cardio. While they might not be as colorful as Nelson they are just slightly more educated about total fitness.
I cut the flexiblity Position Stand because it doesn't pertain to this thread. However this is the Postion Stand of the American College of Sports Medicine.
The American College of Sports Medicine (ACSM) has updated its position stand on the quantity and quality of exercise to maintain cardiorespiratory and muscular fitness. The revised ACSM guidelines include for the first time a recommendation for flexibility training as a component in maintaining fitness in addition to aerobic and strength training exercises.
The ACSM position stand is published in the June 1998 issue of Medicine & Science in Sports & Exercise (vol. 30, no. 6). The 17-page position stand also provides the rationale and supportive research for the recommendations. The following information highlights the ACSM recommendations for exercise in healthy adults.
Cardiorespiratory Fitness and Weight Control
To maintain cardiorespiratory fitness and weight control, the recommendations state that aerobic exercise should be performed three to five days a week for 20 to 60 minutes at an intensity that achieves 55 to 90 percent of the maximum heart rate and 40 to 85 percent of the maximum oxygen uptake reserve. In place of one 20- to 60-minute session on a given day, the recommendations state that two to six 10-minute periods of aerobic activity throughout the day can be used to fulfill the requirements for the amount of exercise.
Muscular Strength
According to the recommendations, resistance training should be a part of a fitness program and of sufficient intensity to enhance muscular strength and endurance and to maintain a fat-free mass. One set of eight to 10 exercises that work the major muscle groups should be performed two or three days a week. The guidelines advocate for most persons eight to 12 repetitions (or to a near-fatigue level) of each exercise.
Cardio DOES...
...make you better at performing cardio
And that's the idea. CARDIOVASCULAR FITNESS.
Why do think all these physicians, who by the way would earn more by not tell people the correct way to maintain their health, would publish a Position Stand in favor of strength training AND cardiovascular training if it wasn't more beneficial to do both.