A power skating exercise device includes a pair of endless guide tracks, each of which have a power section and a return section and a pedal for each guide track. The pedal is mounted on a follower which is slidably mounted in one of the guide tracks. The follower is proportioned to pass freely along...http://www.google.com/patents/US4915373?utm_source=gb-gplus-sharePatent US4915373 - Exercising machine for ice skating
