Fat Burn vs Fitness

tommctech

I recently started using a heart rate monitor to get a more accurate calorie burn while doing cardio and strength training. I've got the strength training down, but I am hoping someone can help me out with the cardio readings. I've got the polar h7 and I have been using the polar app during cardio sessions (mostly the eliptical). There is a meter that tracks fat burn vs fitness/endurance. Being 5'11 and 340lbs, I am gearing towards fat burning. What's happening is I am almost exclusively staying in the fitness/endurance side of the measurement. I typically do on average 25 minutes at around 4.5 / miles per hour and my heart rate stays in the 140s. I have noticed that if I drop my speed down to aroun 3mph, it will slide back over to fat burn. I have two problems with this. First the pace is too slow for me. Second, it's too slow for the treadmill. You need to stay around 2.7mph to keep it running or it will pause the workout until you hit ph or higher.

So any advise on if I should ignore this particular meter and just do what feels right (considering everything I do is probably fat burn) or should I be adjusting my workout?