Learn how astronauts' bodies change when they are in space.
Certain changes have occured in the bodies of astronauts while they are in space. Some changes include:
The astronauts grew 1 1/2 to 2 1/4 inches taller. This height increase was due to spinal lengthening and straightening.
Their waist measurements decreased by several inches, due to an upward shift of the internal organs in the body.
The calves of their legs became smaller because the muscles of the legs forced blood and other fluids toward the upper part of the body, thus decreasing the girth measurement around the thighs and calves.