Long-term space travelers will need high-intensity exercise to protect heart health

As NASA seeks to build a lunar outpost, visit Mars and commercialize spaceflight, the long-term effects of weightlessness on the human heart are of critical importance, according to researchers. By analyzing data from astronaut Scott Kelly's year in space and comparing it to information from extreme long distance, which simulates weightlessness, swimming of Benoît Lecomte, researchers found that low-intensity exercise was not enough to counteract the effects of prolonged weightlessness on the heart, according to new research published today in the American Heart Association's flagship journal Circulation.