Cardio vs Fat Burn

Whenever you get on a piece of cardio equipment you can choose between fat burn mode or cardio. The difference between these two different formats is the heart rate the machine desires you to perform at. The fat burn mose is supposed to burn more fat while cardio strengthens your heart. Its true that you burn a higher percentage of fat while working out on the fat burn setting but doesn't it seem odd that you work so much harder and sweat so much more on the cardio setting? For a very broad generalization, lets assume that 60% of the calories you burn come straight from fat while working at the burn fat level, while on the Cardio setting only 40% is burnt directly from fat. That figure alone would persuade us to simply exercise at the burn fat setting, but we must ask the question percentage of what? One may burn 20% more fat calories while on the burn fat setting but if only a total of 100 calories was expended during the exercise that is only 60 calories. On the other side of the spectrum one can expect to burn around 400 calories while doing cardio for an hour, 40% of which results to 160 fat calories burnt away. End the end cardio is always the best choice is burns more fat, greater calories, and helps to strengthen the heart.