While many of us slog it out on the elliptical trainer every day just to get out daily workout, others are using these revolutionary machines for a lot of different reasons. For many elderly people it's the only way to stay active while many in rehabilitation relies on this impact free exercise to learn to walk again. The real revolution of these machines lie in the natural motion and the fact that it resembles running without the impact makes it a very efficient machine to train on.Elliptical trainers work on cross movement and usually have 2 sets of handle bars. One set is static and allows you to use the machine for lower body workout and you can use it similarly to a stepper. The second set of handle bars corresponds to the leg movement and allows you to use your arms for a cardiovascular workout where you arms and legs are in full flight.When you are running, varying your speed is the only real way to "adjust" the intensity of your workout. With an elliptical, it comes with a revolutionary resistance mechanism. By varying the resistance level you can vary the intensity of your workout. The new machines have magnetic resistance which is very smooth and a very effective way to adjust the intensity of your workout.At the heart of the machine is the flywheel which is what drives the motion of the machine. Most machines have a central flywheel that's located at the back of the machine and the resistance mechanism is directly connected to it. Some of the newer machines have duel flywheels as it helps to reduce the overall size and footprint while making it more stable.The whole trainer is controlled by a screen that is conveniently positioned to allow the user to adjust virtually every aspect of the workout. From speed to resistance and even different workout programs. The latest machines are fully fitted with full color HD TV screen with iPod connectivity.Visit my ellipticals review site and read more about the latest nordic track elliptical.