First Look: JIMMY KIMMEL is celebrating his 1,000th episode Thursday with who else but fitness guru RICHARD SIMMONS and, from the looks of it, audiences are in for a laugh as the "Sweatin' to the Oldies" maestro gets Jimmy into tip-top shape in a wacky new skit!

For the occasion, "Jimmy Kimmel Live" will air a special 90-minute show, beginning at 11:35 p.m. Thursday night on ABC.