Nicole Richie Post-Pregnancy: "I've Lost 10 Pounds from Dancing!"

Credit: Jason LaVeris/FilmMagic

Would Nicole Richie consider a stint on Dancing with the Stars?

Richie, who gave birth to her son Sparrow in September, has debuted an impressively svelte post-baby physique. Her weight loss secret just might be dancing -- to Jay Z!

Sunday, Richie, 28, boasted via Twitter, "I've lost 10lbs from dancing!!"

In a chant familiar to Jay-Z fans, she added, "H to the izzo. V to the izza!!" A subsequent Tweet ("I''m gonna need crutches tomorrow") showed a blurry photo of a concert stage.

Indeed, Jay-Z performed (with surprise guest Rihanna) at L.A.'s Pauley Pavillion Sunday, with Justin Timberlake and girlfriend Jessica Biel also attending.

Sparrow is Richie's second child with partner Joel Madden; daughter Harlow is 21 months.