Self-tutoring about fitness: the tutor reflects about running on a treadmill vs outside.
I first tried running on a treadmill a couple of weeks back. I find it requires greater awareness than running outside, since specific position on the belt is very important.
Supposedly, to exert the same energy as running outdoors, the treadmill runner must go about 15% faster. The possible reason is that the treadmill returns more of the runner’s stride energy.
Source:Oracle Tutoring by Jack and Diane, Campbell River, BC.