4-times number 1 Fitness trainer in America, Samir Becic‘s submission at a Guinness World record was denied. His attempt was running at a high speed on a treadmill while doing 360-degree rotations for a minute non-stop. So far, no one has ever done this before. The original Guinness letter is attached below as well.
Here are some of the videos of him preparing for the stunt:
Here is the original declination email from Guinness: