Originally Posted by
Aimulator64
I prefer to spin at a higher cadence because most of the time when im on a flat, i will burn out before i can get my heart rate up to my max, which i want. Going up a hill, my heart rate goes up farther and for a longer period of time when i keep 90-100 rpm up the hill in a lower gear, which means more time up the hill, therefore more time with my heart rate up, which means more calories and fat burned, etc.
Aside from all the other things wrong with that paragraph, higher heart rate does not necessarily mean more calories burned. Heart rate is just an indicator that heart rate monitors use to estimate calories, it is not itself a cause of the burning of the calories. There are many factors that affect how much oxygen is required for metabolism (oxidation rates are different depending on what is being burned), as well as how much oxygen is being transported by your blood. HR calorie estimation is based on statistical models and is not even remotely a direct measurement of anything.