Is practical to use a mechanical Treadmill? or is key to have a electric one so it push you? I'm close to build a standing-desk and wonder if something like ht

Is practical to use a mechanical Treadmill? or is key to have a electric one so it push you? I'm close to build a standing-desk and wonder if something like http://www.amazon.com/Stamina-55-1610-InMotion-Elliptical-Trainer/dp/B000VICRO8/ref=sr_1_3?ie=UTF8&qid=1359574310&sr=8-3&keywords=step+machine http://www.amazon.com/Stamina-55-1610-InMotion-Elliptical-Tr... could work too...