I've definitely learned that chores take the place of some exercise time. I do 45 minutes to an hour on my elliptical most days, but some days I have too many other things to do, and if I try to do elliptical stuff as well, I wind up with that 'too much too fast too tired' feeling.
I really do like my time on the elliptical, but I have a longstanding reputation of slacking off every other time I tried to get my act together. So that I don't fall into the habit of thinking 'I did a serious chore, so I don't need to do the elliptical', I try to arrange all my running around and heavy lifting chores to the same day (note - I try! reality doesn't always allow for that
). Then I'll do my elliptical the rest of the week. If I have several days of running around or heavy housework stuff, I'll still do the elliptical, but do a lot less time. It keeps the habit, but doesn't wear me out.
I don't count regular housework either. That gets done even on long elliptical days.