The Collaborative International Dictionary of English v.0.48:
Jogger \Jog"ger\, n. One who jogs; as, the paths in Central Park on a summer Saturday are filled with joggers. --Dryden. [1913 Webster +PJC]WordNet (r) 3.0 (2006):
jogger n 1: someone who runs a steady slow pace (usually for exercise)