Originally Posted by
CliffordK
4 miles and you're done. You could do that at a full sprint.
A "real sprint" usually lasts only about 10-30 seconds at most and anything longer then that is not a sprint.
The energy system in a human body can only generate enough ATP to allow about 10-30 seconds of maximal speed or power and after that you slow down. There is no human being who can ride 4 miles in 10-30 seconds.