What Happens To Our Muscles During Spaceflight And When Living on Mars

What happens to our muscles during spaceflight and when living on Mars?

When humanity reached the moon in 1969, this opened the door to space exploration. The possibility of human colonization of outer space has become a reality in the 21st century. However, there are challenges in this endeavor of space exploration and settlement. Space could be a harsh environment to human health. Specifically, the muscular system could be at risk in a microgravity environment such as the Moon or Mars. Physical inactivity poses a risk to astronauts in space. A study by The Journal of Physiology  reached this conclusion when conducting a 21 day simulation. Living on Earth which has a higher gravitational field has made the body unaccustomed to microgravity environments. This could also effect other organ systems, which include nervous, skeletal, and cardiovascular system. There is also the challenge of hypoxic stress. There could be solutions to some of these problems, but long term spaceflight and human exploration could pose significant health risks. If this were to be done, astronauts would have to have a vigorous exercise program or an environment that could generate a gravitational field similar to that of  Earth.

       The experiment only used 11 subjects. What was examined was the specific mechanisms in which tissues were getting energy by means of sugars and fats by means of oxygen. The 11 active subjects would have the knee extensors examined from the exercise session. Mitochondrial respiration was determined by biopsy from the skeletal muscle tissue. Another section of the group examined whole body exercise, producing a fascinating result. The whole body exercise group result in the discovery that hypoxia could be more pronounced during whole body exercise when stress on the cardiovascular system is present. The trouble with this study is that all the subjects were male. There could be a different result for female astronauts that is not accounted for. There are going to be more female astronauts in the future and sex differences should be accounted for.

 The mitochondria and muscles of men and women do not differ. However, body composition and physical fitness capacity is significant. The potential for muscular atrophy is high, Men have a higher muscle mass percentage compared to women. If muscle loss during space travel is high in them, it would be more severe in women. Musculoskeletal mass compared to males is lower in women, which means weight training or load bearing exercise is a necessity. Astronauts must have high level of fitness to survive and  maintain health in space. The whole body exercise portion would be more of a precise assessment compared to examining knee extensions. The reason knee extensions were probably used is it would provide information even if you did not have female subjects. The problem with that is that men also carry more muscle in the legs as well. The physiology of oxygen transport behaves the same, but not the physical fitness capacity.

Fitness levels and an optimum health condition would need to be a requirement before going on a long terms space journey. So far, research has revealed much but more has to be discovered. The research and experiments were conducted by University of Udine, University of Pavia,  University of Munich, the Swedish Aerospace physiology Centre, University of  Trieste,Milano Polytechnic, and the German Aerospace Center. That impressive number of collaborators are taking the next step into space exploration. The chief investigator Bruno Grassi stated ” this research will help prepare astronauts for spaceflight and it improves our understanding of how muscles respond to long periods of inactivity in association with hypoxia.” While these gives some indications a sample size should be larger to include women. From that point other considerations should be made if space colonization becomes realized.

Spaceflight and exploration can effect women as well as men differently.

Women may be more likely to get struvite kidney stones, more urinary tract infections, and orthostatic intolerance. Men do not have as much of  the immune system response compared to women. Being in space can also effect hearing and sight. The experiment conducted is needed to assess possible solutions to maintaining optimal health in outer space and other planets.

         Hypoxia becomes a concern in space and other planets. This condition is when the tissues of the body do not have adequate amount of oxygen. The tissues of the brain, liver, and other organ systems could be damaged if they do not receive oxygen. The study indicated that inactivity is most likely more harmful to the musculoskeletal system in space. Oxygen is essential to the human body. Which explains why hypoxia is a major concern for long term space travel. Cellular respiration requires oxygen to break down sugar for adenosine triphospahte. The by products are CO2 and water.  Oxygen can be considered the fuel of life. The Earth contains 21% oxygen in the atmosphere. Oxygen is one of the most abundant elements on Earth. Knowing this is essential and that the human body had adapted to gravitation this poses a challenge in attempts to create colonies on the Moon or Mars.

          Mars  does have a harsh environment. The atmosphere is 95.7% carbon dioxide, 2.7 % nitrogen and 1.6 % argon. The surface temperature ranges from 125 degrees celsius to 25 degrees celsius  . The planet does contain frozen ice caps, which demonstrates extremes of weather. Mars has volcanoes and networks of canyons. The major hazard is ultraviolet radiation.


The air of Mars is thin in comparison to Earth. It is only 0.6 % of Earth’s atmospheric pressure, but it has enough density to allow for weather on the planet. For a space explorer dust storms pose a risk. High winds enable go through the planet moving the red sands causing both regional and planet wide sandstorms. The axial tilt of Mars is similar to Earth’s. This means Mars has similar cycles of seasons. The ice caps of Mars grow in the winter and shrink during the Martian summer. If astronauts were to go to Mars it the poles would not be a safe landing site. There would also would have to be a consideration of the danger of dust storms. If astronauts were to entering Mars when a planet wide storm happens this could mean serious peril.Mars would most likely be more harsh than some of the deserts on Earth. The planet at one time could have been Earth like and may have contained water on its surface. The evidence could be the scars seen in beds in sedate.

Physical fitness and health condition are essential to any astronaut or space traveler. 

It may be possible if Mars was similar to Earth, that over a number of years it could be made habitable with human engineering. A water supply and an agricultural development would have to develop to make this viable. The planet Mars is in a current state harsh to life that attempts to settle there. Reaching Mars is the biggest challenge at the moment. According to an experiment conducted on the International Space Station, the muscles of astronauts lost 40% of their capacity to do work. This experiment had astronauts up in space for a total of 180 days. Even astronauts in the best shape experienced muscle atrophy. NASA has made a conjecture that it would take at least 10 months to reach Mars, with an intention of a one year stay. The return home would require an other 10 months. If the rate of muscle atrophy is high then this means astronauts would not have the strength to be ambulatory or mobile. The current exercise machines in ships would have to produce more loads to prevent muscular atrophy.

Holding on to muscle mass would require a high weight and low repetition workout. There are two devices that hold the solution to the issue of musculoskeletal heath. The Interim  Resistive Exercise Device and the Advanced Resistive Exercise Device are new technologies that could provide the exercise needed to maintain strength. Machines that contribute to cardiovascular fitness are effective, but more is needed for maintaining the health of the bones and muscles. If this is not done, long spaceflights could be a hazard to health. If people were born in environments that have gravity going to microgravity will be an immense adjustment.

Advanced Resistive Exercise Device

The skeleton and muscles need gravitation. There also is another question related to the circulatory system. While it is clear what can happen to both the muscular and skeletal system it has not been fully elucidated what living in a microgravity can do to the cir circulatory system over an extended period of time. If circulatory system health is not optimal, this will negatively impact the entire body. There either has to be a way to reduce the time of spaceflight or make the human body adjust to the tough environment of outer space.

        The Moon would be the best candidate for possible colonization. Unlike Mars, it does not have intense sandstorms. There is the issue of solar radiation and no atmosphere containing gases. Covered in craters and remains of what was likely to be volcanic eruptions. The surface gravity of Earth’s satellite is only 0.17g compared to Earth’s 1 g. The same problem with musculoskeletal  could occur if one were to stay on the Moon for a long period of time. Spaceflight exercise equipment would still be a requirement. There needs to be more studies  in regards to full body changes due to exposure of radiation or other matter in space. Animals or microorganisms could either be helpful or harmful to human space travelers.


Bruno Grassi stated ”  the results obtained on skeletal muscles, moreover, will have to be interpreted in conjunction with those deriving from other studies of the PlanHab project, dealing with the cardiovascular, respiratory, immune and central nervous systems and metabolism.” There may even need to be an examination of  various cells of the body during spaceflight. Once these problems of physical condition can be solved, travel can be made safe. If a mission to Mars is to happen, the Moon should act as an experimental terraforming site. Spacecraft will have to be more durable if it is to go on extended missions. This means its size will need to expand to accommodate housing needs, exercise space, a work area, and sanitary facilities. Such missions will require huge amounts of finance. This project should not be the task of one nation; it should be a collaborative effort among the world’s astronauts, engineers, astronomers, and astrophysicists. Space should not be militarized, but made into a place of habitable settlement for all. It will only be a matter of time before humanity is able to travel among the stars. The biggest obstacle is getting physically prepared.

What Happens To Our Muscles During Spaceflight And When Living on Mars