A look at the Exercise Regimen of Astronauts in Space

Susan Klatz Beal's image for:
"A look at the Exercise Regimen of Astronauts in Space"
Image by: 

There is nothing that astronauts can do in space that is as important as their workout regime. It is so important that astronauts on the International Space Station are required to work out for at least two hours every day. The force of microgravity (or weightlessness) that astronauts experience in space is one millionth as strong as the gravitational pull that people on earth experience.

Although bodies adapt, they do so with the potential for serious bone loss and lost of muscular strength. On missions that last for less than two weeks, the threat isn't as serious as it is on longer missions.

On April 7, 2009, the results of a joint study between Ball State University and NASA revealed that the kind of exercise that astronauts have been getting is no longer adequate. The research revealed that astronauts on board the International Space Station, where the typical stay is six months, lose 15% of their muscle mass and 20 to 30% of their muscle performance.

When bones that supported the astronauts body weight on earth don't have the load of their body weight to bear, the astronauts will start to lose both bone strength and bone mass and the muscles of the lower body that normally bear weight will start to atrophy.

Astronauts on board the International Space Station are required to work out for one to two hours daily. Although there is no mandatory time stipulation for astronauts on the space shuttle, the general recommendation is that they work out for at least 30 minutes a day. There are three main ways by which astronauts work out.





The bicycle -

When astronauts ride the bicycle, they get a cardiovascular work out and the benefit of some leg muscle exercise. To keep the astronauts in place, they are secured to the bike with a shoulder strap. Although the cardio benefits of riding the bike are certainly beneficial, it doesn't provide enough significant weight bearing impact to stave off bone loss.

The treadmill -

The treadmill can be the most effective way for an astronaut to get an overall workout. On the International Space Station, astronauts wear an elastic harness that pulls them against the running surface in an attempt to simulate gravity and give them the impact that is necessary to prevent bone loss. This process is incredibly uncomfortable for astronauts so they have to stop every five or ten minutes.

As beneficial as they are for the situation they are being used in, both treadmills and stationary bikes cause a lot of vibrations and there is always the potential that those vibrations can disrupt experiments that may be in progress elsewhere in the space craft. NASA devised a sophisticated shock absorption system to prevent interference from the vibrations.

Resistance training -

The newest addition to the astronauts workout regime is resistance training. For this, strong bungee type cords are used as the resistive force. In the future, resistance training will be emphasized rather than the aerobic training that had formerly been the focus.

The newest piece of equipment on the International Space Station is a device known as the Advanced Resistance Exercise Device. This equipment was only brought to the ISS in November of 2008. The new device works by incorporating the bungee type resistance cords with the bicycle.


Astronauts who went up on the Russian spacecraft Mir used the workout regime that the Russians had been using on Mir for the entire existence of the spacecraft. For the cardiovascular workout, astronauts and cosmonauts would spend 45 minutes on an exercise bike. For weight bearing exercise, they would use one of the treadmills on Mir.

To counter the effects of weightlessness, it was necessary to put a weighted load on the machine. Then they would workout for about an hour, alternating between walking and running. In between, they used expanders that provided the resistance training that was necessary to ensure that the rest of the body received a workout.

The expanders would work the muscles of the arms, legs, shoulder and waist. As effective as this regime was, it was painfully uncomfortable, and astronauts and cosmonauts could only endure the pain for five or ten minutes before having to rest and then start all over again.

The exercise regime that all astronauts must go through on any type of space craft is extremely important. The longer an astronaut experiences weightlessness and zero gravity, the greater the potential for muscle loss and bone damage. A good part of every day in the life of an astronaut is devoted to working out. Astronauts who follow the workout regime while in space have fewer problems with muscle and bone strength when they return to earth.


NASA has learned a great deal about the problems associated with weightlessness, and about the potential health hazards to astronauts who spend long periods of time in space. The Space Shuttle program will be retired in the not too distant future. On the next generation of space crafts, scientists, doctors and aerospace engineers will be able to work together to provide the astronauts with equipment that will provide them with a beneficial workout while addressing all of the issues associated with weightlessness.

On future space crafts, there will be less focus on pure aerobic training and a greater focus on resistance work and weight bearing exercise that can prevent the loss of muscle strength, muscle performance, or worst of all, bone loss which can lead to osteoporosis.

More about this author: Susan Klatz Beal

From Around the Web