Answer: MARATHONER

AnswerCrossword Clue
MARATHONERLong-distance runner
MARATHONEROne on the run
MARATHONERAthlete who may "hit the WALL"
MARATHONEROne who can keep on running after hitting the wall
MARATHONEROlympic entrant in the 26-mile race.
MARATHONERHe may hit the wall
marathonerone who takes part in a marathon