Riding a trainer is easier than riding on flat ground outside. Outside you've got things like wind howling at you, potholes to swerve around, vehicles to dodge, etc. Inside you don't have all that.

The idea that riding a trainer is easier is backed up when you look at the 24-hour roller records and compare them with the 24-hour road records. The average speeds on the rollers is considerably higher than the average speeds on the road.
http://www.ultracycling.com/records/...istorical.html


There are, however, some difficulties with riding on a trainer. One is the mental boredom of looking at the walls. You might be able to alleviate that by watching TV. Another has to do with the butt on the saddle. I'm guessing I must move around more when I ride outside because my butt doesn't hurt at all when I ride outside, but it does when I ride the trainer.