On the elliptical I try to go at least a mile in 20 minutes (or less).
To achieve my goal, I have to go .05 miles every 5 minutes.
If I'm just watching tv, I don't keep my HR nor my speed up. I have to watch the clock & mile ticker to get in a great workout.
Now I'm at 1 mi in 17:50 min.
This is also a great way to see how much progress you're really making in getting fit and healthy.
When I started I could do a mile in 23 - 25 min. I'm down to under 18 minutes and am trying to work my way down to a more reasonable number for fitness.