There is no difference in principle between cross trainers and elliptical trainers; rather, they are evolutionary advancements in the way the machines move, making the motion sequence ever more ergonomic and simulating the running motion ever better. An elliptical trainer can also be described as a further development of the crosstrainer. The two terms are often used synonymously. When differences are made, they are usually rather blurred. One term tends to emphasise training with an elliptical movement or the elliptical path of movement of the feet. The word crosstrainer describes rather the movement of the whole body. This is because the arms and legs move in opposite directions, i.e. "crosswise". This is why, depending on the design, one can also speak of an elliptical crosstrainer.