This claim is misleading. Much of the information in the article states that while anyone can run a marathon, medical professionals extremely discourage anyone from attempting a marathon without prior training. While yes, it is possible, and the claim is technically true, it is highly unrecommended. "Running a marathon with zero training is not safe and can put you at risk for injuries and other problems," the source credited states, "...it is technically possible for many healthy adults to finish a marathon without training..." Overall, running a marathon with no training has more risks than benefits, if any at all.