 [ Symptoms ] my period is 3 weeks late and i feel bloated could i be pregnant  my period was due 11114 and i havent had it yet i feel bloated neasous have more headaches than normal soretender breasts and feel more tired than usual took a hpt on 11514 and it was negative a friend said it was too soon to take hpt here it is 3 weeks later same symptoms plus weird food cravings like ranch dressing mixed with ketchup and mayo advice please [ 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