Do you exercise?
I run several times a week to keep fit. When I travel for work, I try to find a hotel that has a gym so that I could use the treadmill.
Running outdoor or on a treadmill both come with advantages and disadvantages. For the same distance I run, there is really no difference in the number of calories I burn.
However, I found that I tended to run a longer distance when doing it outdoor!
What caused this difference?