A navigation-assisted fitness device broadly comprising a location determining component, a fitness monitoring component and a display. The location determining component determines location data for a user of the device as the user exercises. The fitness monitoring component is coupled with the location determining component and calculates fitness information for the user as the user exercises. The display displays the fitness information and other information and data.The fitness information may include an indication of the intensity level of the user's exercise, the total amount of calories burned by the user during the exercise, the amount of fat calories burned, and the amount of carbohydrate calories burned. The device calculates the ratio of fat calories burned versus carbohydrate calories burned based on the intensity level. As the user increases or decreases the intensity level of an exercise, the device recalculates and displays the ratio or percentage of total calories burned from fat reserves and from carbohydrate reserves.