I've had a regualar run, bike, swim, etc. regimen for about 25 year so that is my baseline. I usually get 30-60 minutes in on the week days and 1-4 hours on the weekends.
I don't think that I reduce my calories much when I reduce exercise. That became a problem recently when I had to stop running for almost a year and put on 25 lbs.
The other things that I have noticed is that short (for me) but intense workouts such as a 5k or 10k running race tends to suppress my appetite for an hour or two. On the other hand I eat like crazy after the really long stuff such as a marathon run or a 100 mile bike ride. After something like that it seems like I want to eat every hour or two for the rest of the day.