I have only owned a treadmill for 3 1/2 years. I never could get my brain around how people ran on them.
The first time I ran on one for any length of time, I thought I would lose my mind.
I used to just duke it out in the winter, or not run at all. I used to think treadmills were for people who couldn't handle "real running". I also used to believe in Santa Claus.
With base building, I have found the treadmill to be a valuable tool. On the road, I have found if I am in lala land, I will let my pace creep up when I am trying to keep it slow. I "feel good", so I speed up. Then, I start to not feel good, thus I have to slow down.
Over this last winter, I have put a lot of miles at low intensity on the treadmill. And, I learned a real obvious lesson - It doesn't change its pace. That is the beauty, set it and forget it.
Yesterday I wanted to get in a 20 mile run, and wanted to stay home in case I needed to stop and help with the kids (hopefully I could get most of it done before they woke up). So, I decided to do the 20 on the treadmill (my max on that beast I think was only 15-16).
I set it at 7mhp, knowing my heart rate would stay in the low range for at least 2 hours, and I would watch the last hour.
This same run outside would have taken me over 3 hours, and I would have been pretty sore. I did it in 2:52, and was not sore at all. Avg hr was below 140, with the last 1/2 hour dancing between 147-152. Also, I ate nothing, and only drank one 24oz bottle of water. (those who have run with me would be shocked, as I typically drink 20oz every 30-40 min.)
The lesson - Use the treadmill as a tool to get base miles in without putting much stress on the legs.
Set it and forget it.