Commercial Crosstrainers / Ellipticals

Why use a elliptical Crosstrainer
 
An elliptical trainer (also cross trainer or simply elliptical) is a stationary exercise machine used to simulate walking or  running without causing excessive pressure to the joints, hence decreasing the risk of impact injuries.

Elliptical trainers offer a non-impact cardiovascular workout that can vary from light to high intensity based on the resistance preference. Most elliptical trainers work the user's upper and lower body (although some models do not have moving upper body components). Using an elliptical trainer is designed to elevate the heart rate more than building muscles.