what will happen to the muscles of astronauts if they stay in outer space for a long time
Answers
Long-term exposure causes multiple health problems, one of the most significant being loss of bone and muscle mass. Over time these deconditioning effects can impair astronauts' performance, increase their risk of injury, reduce their aerobic capacity, and slow down their cardiovascular system.
Bone loss occurs in the weightless environment of space because bones no longer have to support the body against gravity. On Earth, gravity applies a constant mechanical load to the skeletal system, that causes healthy bones to maintain a certain density so that they are able to support the body.
Because astronauts work in a weightless (microgravity) environment, very little muscle contraction is needed to support their bodies or move around. Without regular use and exercise our muscles weaken and deteriorate, a process called atrophy.