 [ Symptoms ] what is the difference between the fat burning mode and the cardio mode on the machines at the gym [ Disease ] there are problems with the fat burning option on the cardio machines and it really ought to be eliminated the idea behind the fat burning option is this because fat is denser than carbohydrate it requires more oxygen to burn so to maximize the percentage of fat you burn compared to carbohydrate the fat burning mode would have you work out at a pace at which your body can deliver lots of oxygen to your muscles that generally means a slow pace to keep you from getting breathless the problem is that when you exercise at a slower speed you burn fewer total calories    from both carbohydrate and fat    because you simply do not do as much work further the way to get aerobically fit is to get your heart rate into the training range usually 60 to 85 of your maximum heart rate which is hard to do at slower speeds and fitness is ultimately what you are after whether your goals are better health burning calories or improving heart and lung capacity the bottom line is that the fat burning mode probably will not be intense enough to maximize total calorie  or fat burning or to help you increase or maintain optimum fitness levels use the cardio mode to maximize your exercise benefits using the fat burning mode on exercise machines at the gym actually is not the best way to burn fat the key concepts to understand here are the percentage of calories that come from fat and total calories the fat burning mode is typically set at lower exercise intensity where more calories burned come from fat not as many calories burned during higher exercise intensity will come from fat the point to understand though is that while more of the calories that you burn will come from fat at a lower exercise intensity you have the potential to burn more calories per session doing higher exercise intensity the percentage of calories burned from fat will be lower during the higher exercise intensity but you will be burning more calories overall including the amount of calories from fat also higher exercise intensity leads to a greater boost in metabolism even after you are done exercising which burns additional calories it is best to do exercise that you are comfortable with and that meets your level of trainingconditioning in general however increasing the time spent on exercise and increasing exercise intensity will provide a greater potential to burn more calories and lose weight