Treadmills are, by far, the most popular piece of aerobic equipment.
Using a treadmill takes some getting used to, but most people enjoy the rhythmic movement of walking or running. These movements are also much easier to do for long enough periods of time to be beneficial aerobically, and can be adjusted to be easy enough for someone just starting out, and challenging enough for even an athlete. Always start slowly . Place each of your feet on each side of the belt as you turn on the machine. After you have started the machine and the belt is moving slowly, step on the belt and adjust your speed to a slow comfortable pace until increasing the intensity.