there is something that I am not able to understand in the BMR system.
If I use any online calculator and keep the same information (age, weight, height and gender), then I switch between the 5 activity levels (sedentary, lightly active, moderately active, very active and extra active), I can see a very huge difference in the BMR, almost 400 calories between each activity level for the exact same information.
Now my question:
When we exercise, should we count the exercise calories of everyday or not? since it seems they are counting those in the BMR for people that are more active. Please explain this to me.
And in case we should subtract the calories we burn during exercise, does it mean that more active people will always burn more calories, even when they eat the calories they burn during exercise?
Aside question:
How long do we have to exercise, until we can say that our BMR increased due to our activity increase?
Is it something short like a few days, or long such as a few months. Please let me know.
Thanks


