In summary, based on the detailed video analysis, I believe Amy Hughesâ€™ and Dave Keighleyâ€™s claim that Amy Hughes covered 520 miles over 7 days on a treadmill is false and that she did not break the world record even if we ignore all the other problems with their attempt. The detailed video analysis suggests that Amy Hughesâ€™ true mileage is around 495.3 miles in the best case scenario and 473.6 miles as a lower bound, both of which have a significant amount of beneficial assumptions built in. This is pending verification that there are no other activities indicating cheating from the live stream videos that neither of them are willing to provide.
Also, if you read Amy Hughes' blog article on her treadmill run, we see her claim: "Where this drive came from Iâ€™ll never know but I started cracking up the speed for a few solid hours and somehow smashed out a chunk 9k hours!"
9 k ~ 5.59 mph
I do not at all believe her claim that she ran at about 5.59 mph for several hours into the 5th/6th day of her treadmill run with so much fatigue. None of the analysis of the live stream videos supports that she is capable of this or even did it.