According to a new study in the USA, when NASA astronaut Scott Kelly spent about a year in space, his heart shrank despite exercising six days a week during his 340-day stay. Surprisingly, researchers observed the same change at Benoît Lecomte, which sailed from Japan to the US for 159 days in 2018. The findings showed that resisting gravity over prolonged periods of time resulted in heart shrinkage and brain cell loss, and vigorous exercise was not enough to prevent this condition.
Scientists explained that gravity helps the heart maintain both size and function while continuing to pump blood through the vein, explaining that when this force is removed or displaced, the heart shrinks in response.
NASA astronaut and flight engineer Scott Kelly lived without gravity on the International Space Station from March 27, 2015 to March 1, 2016. He exercised on a stationary bike and treadmill for two hours each day, six days a week.
Lecomte, on the other hand, traveled 3 kilometers every day between June 5 and November 11, 2018, and swam an average of six hours a day. Although Lecomte was on Earth, staying in water for hours a day changed the effect of gravity on his body.
Long distance swimmers use the prone position technique to increase their stamina.
The researchers hoped that the physical activities performed by both men would prevent them from experiencing any shrinkage or weakness in their hearts. However, data collected from heart tests before, during, and after these extreme physical events showed otherwise. Kelly and Lecomte experienced a loss of mass in the left ventricles of the heart and the first decrease in diameter during their experience. The study in question was published in the journal Circulation of the American Heart Association.
Dr. While Benjamin Levine pointed out that they were working on two men, both of whom did extraordinary things, more studies were needed to understand how the human body reacts in extreme situations.
On the other hand, the researchers explained that the shrinking heart adapted to body functions over time and did not cause any adverse effects now. Levine drew attention to the flexibility and adaptability of the muscle mass of the heart, almost three quarters of which respond to physical activity.