Compare two individuals. Both have a MHR of 190. #1 is an athlete and has a RHR of 40, the #2 has a RHR of 60. OK. They both want to lose a few pounds.
Example 1: Using Karvonen, 50% for #1 is 115. For #2 50% is 125.
Does #1 burn a higher percentage of fat because he's at a lower HR?
Example 2: If both workout at the same HR of 125, that's 57% for #1 vs. 50% for #2.
Does #2 burn a higher percentage of fat because he's at a lower HR percentage?
I've read in a lot of places that fitter people burn a higher percentage of fat at a higher HR percentage but never figured out why. Is it then just a matter of looking at the numbers, the only adaptation responsible being a more efficient cardiovascular system?
My suspicion is #1 is correct and #2 is wrong. Thoughts anyone?