This is not part of my book, it is just so thoughts, ideas I want to save and possibly follow up on.
For older folk, if any sort of hard exercise simply shuts down fat burning, what is a person to do?
I saw a research paper, not handy at the moment, that basically said:
if a person exercises a lot (that magic hour of stored fuel) to burn most of up,
the replenishment of "ready fuel" will come from either
1) the stomach, etc if there is anything there, or
2) fat cells if the stomach, etc is not contributing.
What this means is that if a person gets up in the am and then does a
fasting walk and waiting a bit before breakfast
the greedy fat cells don't have a lot of choice.
They, too, have been selected to not just hoard fuel, but to cheerfully provide it if it is really, really needed. Like the brief rest when the lion was avoided but before the next one found'ya.
So, max heart rate declines about 1 beat/year.
If this continues unto old age, it becomes a "problem".
Think about the simple issue of eating:
70% (220-age) - digestion starts slowing
age 80: 98 bpm / 112
age 120: 70 bpm - no fat, 80bpm - no digestion
So, if it continues, it would be very hard to survive beyond 80 if a person did any sort of exercise.