I hate treadmills so much. Can someone explain the 1% incline rule that must be done so that the pace is correct for outdoors? Why don't they make all treadmills at a 1% then?
FWIW, the last time I was on treadmill I set it at 7:00 pace for 4 miles and it felt like a tempo effort.
Somebody (Jack Daniels??) came up with the 1% rule of thumb. Everyone is different, so it is just a rule of thumb. A properly calibrated treadmill is moving at the speed noted -- whatever the incline is set for. Because you are running in place (body not moving forward), the air resistance that you would experience if your body was moving forward is missing. Although body temperature rises because there is no air resistance to cool you off, overall the effort at 0% is SLIGHTLY easier than if you were running outside.