This is one of my favourites too. It really brought out the quintessential Elvis.
The early version, as seen in Elvis: That's The Way It Is, showed a more exaggerated stop-start section where Elvis did his memorable fist pumps.
Later, in the mid-seventies, he varied it by going into a karate-type stretching routine that drove the audience wild. There's a great clip on Youtube that shows this and a number of other songs (wearing the Bicentennial suit at the Atlanta afternoon show - June 5, 1976). The sound is foggy and muddy, but you can really see him taking this song to the nth degree.
"It is easier for a rich man to get into heaven than it is for a camel's butt to get through the eye of a needle" - Elvis Aron Presley