The low-impact cardio machine with two foot pedals and moving handles that mimic a striding or climbing motion is an elliptical trainer. Also called a cross-trainer, it lets users move their legs through a smooth elliptical path while keeping their feet in contact with the pedals.
That continuous motion reduces the repeated foot impact associated with running on a treadmill. Many models also have linked handle-levers, allowing users to push and pull with their arms while their legs drive the machine. This can involve both the lower and upper body, although some elliptical models have stationary handles.
Elliptical trainers entered the fitness-equipment market in the 1990s. Precor introduced its Elliptical Fitness Crosstrainer in 1995, using a mechanism designed to reproduce a natural heel-to-toe running motion. Unlike a stationary bike, the user stands upright; unlike a rowing machine, the motion does not involve repeated seated pulls; and unlike a treadmill, there is no moving belt beneath the feet. Resistance, incline, stride length, and direction can vary by model.