In a new study trying to find out why researchers gave six NASA astronauts MRI scans before and after long stints in space and concluded that the astronauts grew a couple of inches, but lose vital muscle mass that doesn’t come back when they return. Astronauts on longer stints in space, like when onboard the International Space Station, often complain of a backache. Adding more core-strengthening exercises, like those recommended for people with back pain on Earth, would help astronauts in space and yoga could also prove helpful, Chang said.

Astronauts Get Taller In Space – But Pay The Price In Ongoing Back Pain – Forbes