When you perform exercise different intensities of heart rates use different fuels. When you are at a state of complete rest you are burning mostly fat as fuel, the more you up your heart rate the more you start to split fuel usage between fat and stored glycogen. The basic idea is that if working at a 50-70% heart rate you are going to be burning mostly fat as a fuel source while still active enough to be burning a large amount of energy at the same time. Sounds like a good idea but here is the problem with that.

First off this is the worst state to be in for protecting your muscle glycogen. What do we want to do during a cut? We want to protect our muscle glycogen. Second remember that losing fat is about an overall energy deficit.

Don't we want to burn stored fat? quoting u above makes me thiink i should sit on my arse all day. Though, if i understand correctly ( and sure i don't) that the stored glycogen in the liver and muscles will basically become fat if not used, correct? So, when we sit on our arse, we burn fat stores but thiis will just be replaced by the excess glycogen, right? Though, if we work out, at let's say the 60 -70% rate, some glycogen and fat stores along w/ some protien (protien my understanding) will be consumed, right? But higher the intesitity, the more of what is burned?

Now, I ask this because, there was a point where my normal runs were between 7 - 7 1/2 min miles. then years later after not exercising any level of where i was and being competiitive w/ myself, i would push myself on the treadmill to avg a 8:35 min mile. didn't start out that "low", started more at 9:30 min/mile then ended the 3 mile run w/ a 7:?30 min mile for the last 4 miins. or so. The thing I noticed is it didn't seem to be helpiing me lose fat.
Started thinking that somewhere i read, certain zones - i was usually in the 85% hr zone, burne different fuel. Thinkiiing, crap, yeh, my heart can take it but not helping my wt issue.
So, please explain these rates and the advantages. At this point want to get rid of fat stores

Another questiion about heart rate? When we work out, we want our heart rat e to increase in order to burn more fat/glycogen, right? Higher heart rate more energy expanded, right?

So, then if person A & person B eat the same amount exercise the same, if person A has a restng heart rate of let's say 55 & person b has a resting heart rate of 75, wont person b automatically burn more energy, hence not gain wt like person A. Just a thought there. Why?
Cuz, I have always worked out and haven't really worked out like I use to, but do know from all the years of aerobic exercise have a resting heart rate of 55. Female and 39 yrs old.

thanks