It may be slower than the current world record.
I have run just a fraction under 2:29 and ran 120 mpw while training for it. I also have a mile PR of 4:10. There is no way that I could have finished the 26x1 mile workout at 5:40 pace. If you have ever done 32x400m then you know how you feel later in the day. A marathon is easier than 32x400m at marathon pace.
Some people are different than me but my legs would not cooperate and I would run the last 10 miles over 6:00 pace.