According to a new study published in the journal Circulation, scientists have found that the heart shrinks in space.
The study analysed the heart of Scott Kelly, who spent almost a year in the International Space Station between 2015 and 2016. Researchers found that the largest chamber of his heart shrank by over a quarter by the time he returned to Earth.
Astronauts also tend to develop brittle bones, swelled heads and squashed eyeballs.
The heart does not pump as hard due to the lack of pull of gravity and thus becomes unfit.