The Proform Elliptical Machine is a great workout machine. I like my Proform Elliptical Macine and it has some similar features that my Proform Treadmill features. The Proform Elliptical has a fan and also connects to iFit to help you come up with a workout. You can also chose the difficulty, which runs from walking to skiing, which makes it more difficult to push down. The machine also works out your arms as the handles move with your legs. This machine provides a great workout, yet easy on your knees and ankles. I fell and hurt my knee probably about 8 to 9 months ago and on occasion it hurts when I go up and down the stairs, but on the elliptical, I feel no pain in my knee.