Bulked-up, mutant "mighty mice" held onto their muscle during a month-long stay at the International Space Station, returning to Earth with ripped bodybuilder physiques, scientists reported today.
The findings hold promise for preventing muscle and bone loss in astronauts on prolonged space trips like Mars missions, as well as people on Earth who are confined to bed or need wheelchairs.
A research team led by Dr Se-Jin Lee of the Jackson Laboratory in Connecticut sent 40 young female black mice to the space station in December, launching aboard a SpaceX rocket.
In a paper published in the Proceedings of the National Academy of Sciences, Lee said the 24 regular untreated mice lost considerable muscle and bone mass in weightlessness as expected — up to 18 per cent.
![There's a major size difference.](https://www.nzherald.co.nz/resizer/v2/BTLW5TC2KU244ZY25IPCBQ5NQY.jpg?auth=7c2f963fddd1156669ea771d0b75ed90a8a3a392bc73d89d8851115a4fe264c5&width=16&height=16&quality=70&smart=true)