As I understand it, the body has enough glycogen to fuel about 3 hours of moderate exercise, is that right or in agreement with your sources? So any bout of exercise less than a long distance run, one *should* be able to rely on fat as fuel, no?

We also have to add in the cardio vascular efficiency of the heart. I'm struggling to remember the formulas right now but I believe that one still requires oxygen in certain amounts even to burn fat, isn't that correct? If that is the case one could increase the body's fat burning efficiency over the long term with increased CV values.

If this thread goes any longer I'm going to have to get out my books! LOL!!
Very interesting thread, thanks to all for participating.

AL

p.s. I have a watch heart rate monitor and do check it throughout the day and a couple times during a workout.