On an elliptical trainer, you push on the pedals to move forward, much like a conventional bicycle. It is ideal for people with joint problems among others. This is a non-violent exercise. The downside is that you have to work against the resistance of the pedals. This is not very natural unlike a treadmill which we walk as we do forever. You must have some resistance to raise your heart rate. You will not lose weight if your heart rate is still very low.