New research by UT Southwestern scientists found that the heart of an astronaut shrank or is left smaller even with regular exercise.

New research by UT Southwestern scientists found that the heart of an astronaut who spent almost one year aboard the International Space Station or ISS shrank or is left smaller even with regular exercise.

According to a Phys.org report, with NASA getting ready to send humans to Mars in 2030, researchers are examining the physical impacts of spending long periods in space.

The results were said to be comparable with what the study authors discovered in a long-distance swimmer who spent almost one year attempting to cross the Pacific Ocean.

This new research that came out in Circulation (Cardiac Effects of Repeated Weightlessness During Extreme Duration Swimming Compared With Spaceflight) shows that Scott Kelly, now a retired astronaut, lost an average of 0.74 grams or about three-tenths of an ounce each week in the mass of the left ventricle of his heart during the 340 days he spent in space from March 27, 2015 to March 1, 2016.

Functioning Heart Despite its Shrinkage

The finding of the astronaut’s smaller heart occurred despite his weekly exercise regime of treadmill, cycling, or resistance work for six days.

However, according to UT Southwestern Internal Medicine Professor Benjamin Levine, MD, despite the shrinkage, along with an initial decline in diastolic diameter of the left ventricle when relaxed to fill with blood, the astronaut’s heart was able to adapt relatively well.

Dr. Levine, who’s also the founder and director of the Institute for Exercise and Environmental Medicine or IEEM at Texas Presbyterian Hospital Dallas added, the astronaut’s heart did shrink slightly.

He also said, it did atrophy and did get a bit smaller, although “the function remained good.” Levine explained too, that he thinks this is encouraging for a long-period space flight. It shows that even after one year in space, the heart is adapting relatively well.

Originally published at The Science Times