I think the speeds of the treadmill vary by person. I can tell you that I do the brisk walk at 4.3 and the run at 5.8. You want to push yourself during the run, but not so much that you are out of breathe. If you can talk then you are doing okay. The first day I did it I walked at 3.8 and ran at 4.5, but I could tell at the end that I needed to push myself a little more. I would just play with the speeds and see what works for you. And from what I have read the 1% incline more closely mimics outdoor running than keeping the treadmill at 0.
~H~
Mom to 3 sweet kids
2003 ~ 2005 ~ 2009