Here on Earth, everyone knows exercise is important, but in the weightless environment of space, it’s really important. Research at the Johnson Space Center shows that being in a restricted low-gravity space for long periods of time reduces bone density, causes muscular atrophy, induces loss of calcium, and introduces possible metabolic and cardiovascular problems. That makes frequent exercise vital to an astronaut’s health.
However, you can’t exactly do jumping jacks in the confines of a spacecraft. Besides, weightlessness prevents engaging in typical Earth-bound exercises. Apollo 7 was the first time astronauts had enough room to exercise, and in preparation for the flight NASA experts sought an inflight exerciser that was small and lightweight.
Enter the Exer-Genie Exerciser, an off-the-shelf device developed in 1961 by Exer-Genie, Inc. of Fullerton, California. According to the company’s website, “The American Space Program was experimenting with ‘Fitness in Space’ when a variable resistance rope friction device which was originally designed to lower people from a burning building … was adapted to a small exercise machine and named Exer-Genie Exerciser.”
NASA evaluated the exerciser at the Lockheed Human Performance Laboratory in Sunnyvale, California. Their findings indicated that the appliance could be extremely effective in conditioning muscles and maintaining bone mass in weightlessness.
The Exer-Genie weighs less than two pounds and takes up very little room. A specially woven nylon rope goes around a metal shaft, and pulling on the rope causes friction. In a spacecraft, astronauts hooked the device on the wall of the spacecraft. By pulling on the cord in a controlled way at varying speeds, astronauts could perform exercises closely related to isometrics (pushing or pulling against an immovable object) and isotonics (moving exercises such as calisthenics or weight lifting). The apparatus allows for more than 100 basic workouts, and has the added advantage of adjustable resistance, so each Apollo astronaut could set it to his own physical conditioning level.
Another plus for the Exer-Genie was its ability to save time. Quoting an article titled Body-Building Boons from Apollo on the NASA website, “Advocates of ‘isokinetics,’ as some call the controlled resistance exercise method, say that 12 to 15 minutes of daily effort provides the equivalent in cardio-vascular improvement and general physical toning of 40 to 60 minutes daily work in isometrics-isotonics.”
Exer-Genies were carried on every crewed Apollo mission and actually used on Apollo missions 7, 8, 9, 11, 12, and 16, and later on Skylab. Typically, astronauts used it several times a day for periods of 15 to 30 minutes while in the command module. After the Apollo 11 mission, Neil Armstrong stated they “did a little bit of exercise almost every day. The Exer-Genie worked alright. It got a little hot and stored a lot of heat, but it was acceptable.”
According to the NASA article mentioned above, Apollo 7 Astronaut Don Eisele, who had reported that his lower abdominal muscles ached from “floating around in the seated position,” told mission control that he felt a lot better after using the Exer-Genie. His crewmates Walter Cunningham and Walter Schirra also reported the exerciser was a “good deal.” Schirra even went so far as to say, “One of the best ‘spacey’ things we’ve had in years.”
Some astronauts did not value the Exer-Genie very much, as it did not produce significant results. Its main contribution to the space program was its ability to stretch and exercise sore abdominal and back muscles.
Given today’s lengthy stays on the International Space Station, exercise is even more important, and astronauts and cosmonauts exercise two hours a day using equipment that has been specially designed to mimic exercise on Earth. These include a treadmill, stationary bike, and weights. The Exer-Genie’s days in space are over.
Kathleen Hanser is a writer-editor in the Office of Communications at the National Air and Space Museum.