Chaz Bono has vowed to boogie his "butt off" on 'Dancing With The Stars'.

The 42-year-old contestant - who was born a female named Chastity and began gender reassignment surgery around three years ago - explained he and professional partner Lacey Schwimmer plan to show their appreciation for their fans' support by performing to the very best of their ability when the show launches on September 19.

Writing on his twitter page, Chaz said: "Thanks again to everyone for all the support, @LaceySchwimmerand I appreciate it. To show our gratitude we'll dance our butts off 9/19. (sic)"

However, Chaz admitted he is intimidated by fellow 'Dancing with the Stars' contestant Carson Kressly's moves, as he thinks the celebrity stylist will be "fierce competition".

He tweeted: "@CarsonKressley I bet you're going to be fierce competition. (sic)"

Chaz's dancing partner Lacey recently revealed the star has already lost 5lbs in six days of training for the show.

She said: "He's lost 5lbs in six days. It's so great. He says he's not eating any differently, he's just dancing.

"He's such a great guy. He is so nice, and he's such a kind person. He's awesome. I couldn't have asked for a better partner this time."