Swing dance champion Robert Royston, featured in the Broadway musical Swing!, will teach a weekly Cardio Swing class on Saturdays at Crunch Fitness (1109 Second Avenue at 59th Street). Classes will take place at 10:30 AM.

The program is scheduled to run through February but an extension is likely, show sources said.

Music is an essential component of the Cardio Swing program, and Royston's class features Big Band swing tunes from the '40s to music from the original cast album of the current Broadway show, Swing!

The recently completed Swing! cast album will be released on Jan. 25.

Royston's Cardio Swing features an "add-on aerobic format" with a basic introduction to swing steps, basic jig walks, Charleston kicks and shim sham moves. Partnership is the foundation of swing dancing, and together with his partner Laureen Baldovi (also featured in Broadway's Swing! at the St. James), Royston has built an impressive record in the world of dance.

The team has won more U.C.W.D.C. Master's Division championships than any other couple in the history of country dance (including the '95-'98 World Championships), and has also won their Star Award as Favorite Male Instructor. The team's other titles include:1997 TNN Country Dance Invitational, 1994 American Swing Dance Championships and the '95-'98 U.S. Open Swing Dance Championships.

Broadway's Swing! opened Dec. 9 at the St. James Theatre at 246 W. 44th Street. Information on the show is available by visiting www.SwingOnBroadway.com.

Royston's Cardio Swing class is offered from 10:30 AM -11:45 AM at Crunch Fitness, 59th Street (1109 Second Avenue). For additional information contact Dayna Crawford at Crunch (212) 993 0300.