Proform iSeries 660 Treadmill Review
TREADMILL DOCTOR NOTE :
Using the word strong with $600 is tough but you ought to see the motor they used in this one. We still would only use it for walking. Proform has come a long way in a short amount of time but if you are a serious trainer, you still need to get a serious treadmill.
One of the strongest $600 treadmills on the market. The only problem is that Proform is making these treadmills look so good that people start believing that you can do marathon training on them and they simply aren't built for the serious user.