The Exercise Shuttle

Prior to the launch of NASA's Skylab space station in 1973, the agency hired Boeing engineer Gary Graham to devise a cardiovascular exercise machine that would keep the heart in shape and optimize blood flow. Astronauts would also have to be able to use it in space. Graham and his team at NASA ultimately produced an exercise machine for astronauts called the CMC Shuttle 2000.

To use the CMC Shuttle, astronauts lie on their backs on a carriage that glides on a rail. Next, they push their feet off a kick plate and then pull themselves while holding on to adjustable elastic cords that provide resistance. With every repetition, the machine moves the user's diaphragm and exercises the chest cavity, attracting blood to the heart and helping maintain both heart health and overall blood flow.

Astronauts used the CMC Shuttle on the 84-day Skylab mission from 1973 to 1974. Based on observations of the hearts, muscles and blood flow of the astronauts who used it in-flight, further refinements were made to the design. A company called Contemporary Design licensed the technology from Graham and NASA in 1991 and produced a commercially available piece of equipment called the Shuttle 2000-1. Primarily found in diagnostic and rehabilitation environments, it's one of the few machines to be used by patients on bed rest. Not only does it keep these patients' hearts healthy and their blood flowing properly, the Shuttle 2000-1 prevents seldom-used bones and muscles from atrophying.

High-level athletes also use the Shuttle 2000-1. The exercises performed on the machine -- called plyometrics -- provide strong, fast, muscle contractions. These exercises treat muscles like loaded, coiled springs, providing huge bursts of speed and power when released. So, whether the need is for rehabilitation, maintenance or taking the body to the next physical level, a machine developed by NASA for astronauts makes it possible.