runaholic

Noun

 * 1)  One who is addicted to running.
 * 2) * 1987, Chris Pepper Shipman, I'll Meet You at the Finish!, Life Enhancement Publications (1987), page 65:
 * One such woman complained, "My husband has become a 'runaholic'. He constantly talks about his running time, his equipment, people he has seen doing unusual things while he was running and on and on and on.