Stationary bikes, also known as exercise bikes, have been a popular form of indoor exercise equipment for many years. When it comes to describing these machines, there are several synonyms that can be used. One common synonym is the term "spin bike," which is often used to refer to indoor cycling machines that offer a more intense workout. Another synonym for stationary bikes is "recumbent bike," which describes machines that have a reclined seat and backrest for added comfort. Other synonyms for stationary bikes include "upright bike," "fitness bike," and "cardio bike." Regardless of the term used, stationary bikes offer a convenient and effective way to stay in shape without having to leave your home.