Chaz Bono has lost 5lbs in six days during 'Dancing With The Stars' rehearsals.

The 42-year-old contestant - who was born a female named Chastity and began gender reassignment surgery around three years ago - is feeling the strain of the rigorous practice sessions, according to his professional partner Lacey Schwimmer.

The 23-year-old beauty 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." 

Lacey explained Chaz - who is the son of musician Cher and her late ex-husband Sonny Bono, who famously collaborated on 1965 number one 'I Got You Babe' - is not interested in dancing to any of the tracks his parents have recorded, despite 'Dancing with the Stars' bosses being keen to make it happen.

She added to People magazine: "Chaz has already told me he doesn't want to dance to any of his parents' songs. But the show really wants it to happen, so we'll see." 

Chaz recently revealed his training sessions with Lacey are "going really well" and he appears to be making good progress after having a "little breakthrough" while learning some of his dance moves.

He tweeted: "Dancing rehearsal with @LaceySchwimmer is going really well. I had a little breakthrough today and I'm getting all the choreography down."

Chaz previously explained his famous mother thought it was "great" he is set to appear on the programme and she has been making sure he was not nervous about dancing on TV.

He said: "She really thought it was great that I was doing it and wanted to know how I was feeling about it, if I was nervous and how it was going."