Janet brought her Miss Jackson days on this one!
The singer stopped by The Tonight Show and plugged her Nurtrisystem diet to Jay Leno.
She was stern with the host and whipped his butt into with the help of her trainer!
Jay's workout was specially tuned to the host and one of his Harley. He got quite the ab workout thanks to Janet!
Check out the video above to watch Jay Leno burn some calories!