Astronauts go through many physiological changes during their time in spaceflight, including lower muscle mass and slower muscle development.
Similar symptoms can occur in the muscles of people on Earth's surface, too.
In fact, it could affect everyone to some extent later in life.
"Age-related skeletal muscle disorders, such as sarcopenia, are becoming a greater concern in society," said Hiroshima University (HU) Professor and Space Bio-Laboratories Director Louis Yuge.
"It is especially a big concern in Japan, where the number of aging people is increasing."
In a study published in Microgravity, a medical research group at HU led by Yuge shed light on these similarities.