In the context of calories burned, most people in office jobs will fit firmly within ranges usually given for sedentary people. It takes a lot of physical activity outside of working hours to make up for an office job.
E.g. for me, an hour of high intensity exercise five days a week still placed me firmly in the sedentary range.
Part of the issue is that we tend to "forget" about the hours spent at work when evaluating if we consider ourselves active.
I haven't really looked at sedentary ranges, can you point me to the guideline you reference? Are they based on calories burned during an activity, amount of activity, time in HR zones?
As for intensity exercises, unless you actually measure your activity it will be difficult to estimate exactly how much time you're active inside of your hour exercise. I would guess a lot of people will over-estimate how much active time they really had. For example, weight lifting would be on the low side, HIIT classes somewhere in the middle and running/rowing/cycling on the high side.
It's been a long time since a looked at it in any detail, but a quick search for "calories burned sedentary" gave me a page full of calculators and estimates.
Looking quickly at a few of them, they mostly have tdee estimates for my age now that were still to high for me at the peak of my exercise fitness a decade ago... That includes the calculators trying to take weight and height into account.
The issue is that most of these are repeating and deriving categories based on guidelines set at points in time when a much larger proportion of the population had jobs that involved physical exertion.
And so you can be much more active than average for todays population and still be considered sedentary relative to the activity levels assumed in guidelines.
E.g. the UK NHS guideline of 2500 kcal for an average male would take me adding a couple of hours of walking during the day to reach despite exercising more than average...
And I'm sure you're right that people's failure to estimate their activity when they are exercising or being active is also a big part of it.
I think it is even more complicated. When I was having after work activities that required me to walk to places, load/unload shelves, water the garden etc, I started loosing weight more then when exercising. And all those activities were not intensive at all. I was moving little bit a lot of time, basically.
Same goes when I go for hikes in summer. I am loosing weight, but I am walking at comfortable pace max.
I did not felt hungry at no point either. I dont know what it is, but intensity is not the only factor.
Wearing a Fitbit 24/7 was enlightening in terms of seeing how little activity it takes to get a fairly substantial increase in heart rate, so yeah, just amlittle more activity sustained over hours can make a huge difference.
E.g. for me, an hour of high intensity exercise five days a week still placed me firmly in the sedentary range.
Part of the issue is that we tend to "forget" about the hours spent at work when evaluating if we consider ourselves active.