The Burner feature gives you insight on how fast you are burning grams of fat and carbohydrates while exercising.
To use the Burner with Suunto 5:
You can follow the rate of burning fat and carbohydrates in grams/hour while you are exercising as well as how much you have burn in total during the exercise. The burn rate will change when the intensity of the exercise increases or decreases.
The Burner feature also shows how much of the calories you are currently burning are coming from fat.
One gram of fat contains 9 kcal of energy where as one gram of carbs contains 4 kcal of energy.