Thirteen out-of-shape adults, none of them runners, sign up for a nine-month experiment: train for the Boston Marathon under Olympic marathoner Uta Pippig and find out whether ordinary bodies can be built to cover 26.2 miles. NOVA follows the group through group workouts, injuries, and setbacks, while physiologists explain what is actually happening inside them as they train, from how muscles adapt to prolonged exertion to how the heart and lungs respond to months of accumulating mileage. Interviews with sports scientists break down the biology of endurance, dehydration, and fatigue, translating lab research into plain terms using the participants' own progress as the case study. The film does not treat the marathon as a stunt; it treats it as a controlled test of human adaptability, with cameras present for the training runs, the setbacks, and finally the race itself in Boston. The stakes are personal rather than dramatic: whether people who started the film unable to run a mile can finish one of the world's oldest marathons on their own two feet.