For full-body workout, I suggest a rowing machine. It doesn't take up much space. Exercise bike is alright, but there is a catch. For some people their legs Â get tired before their heart rate reaches 80% of the max value.
That is correct. Most people do not use the bike correctly...they get on, and watch tv or something while casually cycling...which is better than no exercise, but a lot of time is wasted. If you go to a spin class, you'll feel the difference. They make you do a lot of sprints etc. to keep your heart rate up there. My preference of cardio... stairs > treadmill > elliptical > rowing > bike