Problems

Alice and Bob are running a marathon (26.2 miles).  Alice runs at a constant speed and covers one mile every 8 minutes.  Bob runs at a variable speed, but runs every mile in exactly 8 minutes and 1 second.  (i.e. no matter where he is on the track, he will be one mile farther in exactly 8 minutes 1 second.)  Is it possible for Bob to finish the marathon faster than Alice?

But if he speeds up like fuck at the 26 mile mark, how do you know he won't run the 25.1-26.1 mile in less than 8.1 minutes?