The dream of traveling into space is desired by many, however, there are serious consequences for those who wish to achieve it. In a research recently published in the journal Circulation, astronaut Scott Kelly found that he had his heart mass shrunk by 27% after spending 340 days on the International Space Station (ISS).

Even though it sounds like something totally negative, professor and author of the study Benjamin Levine, from the University of Texas Southwestern Medical Center and Texas Health Presbyterian Dallas, revealed to the New York Times that this is a reflex of adaptation. When we are on Earth, the heart's function is to pump blood to move it up while gravity pulls it down. Now being in orbit, thegravity ceases to be a primary factor, causing the organ to shrink to another size.

Only an astronaut's heart shrinks?

The research had also been conducted with a swimmer. Benoît Lecomte is a long-distance professional and had his heart mass reduced by 25% while attempting to cross the Pacific Ocean.

The journey took 159 days, where it was done so that Lecomte could swim and sleep. Although it may not seem like it, the astronaut and the swimmer have one similarity in common: both spent most of their time horizontally.

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Scott Kelly spent approximately 1 year in space travel, in the years 2015 and 2016. This trip served as a study object, so that the impacts could be evaluated due to the duration that was away. During a report for National Geographic, Catherine Zuckerman that such trips do not affect your DNA, eyes, intestinal microbiota and your arteries.

To prevent major complications from occurring, the astronauts undergo an intense and rigorous series of daily exercises, either on the ergometric bicycle, treadmill and other training.

What happens when the heart shrinks?

It may seem something very negative for the body, after all, who wants to go into space and have their heart atrophied? Nobody! However, it is worth noting that, upon arrival at the ISS, astronauts continue to exercise regularly, so that the organ can adapt to the new gravity in which it was placed.

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As much as the blood-pumping organ will shrink, atrophy and get smaller, no more serious or irreversible damage happens, so all is well. The next study, which is already underway, is trying to understand what the effects of space travel are on the hearts of various astronauts who have different levels of fitness prior to their ISS missions.

Soon after his last mission, astronaut Scott Kelly retired from NASA, being called to carry out research for the improvement of future crew members. Currently, his body is already recovered from the changes caused by the time he spent away from the Planet Earth.

With information from Smithsonian Magazine.