Originally Posted by
R. D.
Read my post again while keeping in mind that one of the definitions of zone 2 is that you are burning MORE fats than sugars... which is not true anymore above zone 2. My post remains true during the 20-30 minutes adaptation time you are still burning more sugar than fats despite a lower HR and power.
So the point is that if you'd do 10 minutes HIT then 20 minutes "zone 2", then repeat this pattern, you would never be in zone 2, despite the fact that most apps would tell you 2/3 zone 2, 1/3 higher zones.
Maybe not what you meant, but that's how I read it and how I still read it.
remember that if you go above zone 2, it takes 20-30 minutes for your metabolism to come back to fat burning, so even detailed HR/power stats won't tell the whole story...
Ones metabolism is still getting energy from fat during any effort level. Maybe not a majority of energy from fat. So there isn't anything for the metabolism to come back to. It never stopped burning fat.