That depends on how young you are. Generally, the length of a treadmill is about 2m, that of an elliptical machine is about1.5m, and that of a spinning bike is about1.2m.. If you are small, you can only configure small pieces, such as dumbbells and horizontal bars. General fitness can choose treadmills and elliptical machines. If you want to do anaerobic exercise, you can choose spinning bike, which doesn't take up space.