Oh wow! Im lost. I have the same problem with the machines at the gym! this is my deal though. If I choose fat burn at my gym then I have a hard time keeping my heart rate as low as it tells me to (130) and I wasn't getting results so the past 2 days I have chosen cardio instead, It tells me to get my heart rate up to 160. And I work my butt off and I can barely get it there and it's impossible to keep it there. It wants to be at 152 about even if I kick my *** going harder and faster. Im 20 years old and according to that scale above my cardio heart rate should be 200!!!! Oh my! What should I do???