The singer is one of a troupe of celebrities learning gymnastics in the new BBC One Saturday night programme.
But the intense training – four hours per day – has left her worried she’ll lose her feminine curves.
Amelle, 30, says: “I’ve noticed changes in my body and everything’s tightened up. But I don’t want to lose my curves – my bum has to stay exactly how it is.
“I’ve lost quite a bit of weight but I don’t like that. I’d like to put on half a stone if I’m honest.
“I’ve also got some serious back muscles, which is a bit too much. I just don’t want to look like a man!”“I’ve noticed changes in my body and everything’s tightened up. But I don’t want to lose my curves – my bum has to stay exactly how it is”Amelle Berrabah
Tumble kicks off tomorrow and Amelle will compete alongside celebs including singer Sarah Harding, 32, Towie’s Lucy Mecklenburgh, 22, and Steps star Ian “H” Watkins, 38.
Already there have been a slew of injuries with Mr Motivator forced to pull out of the show after hurting his knee and Amelle suffering a nasty ankle injury.
And she admits it is hard to get over the fear of hurting herself when she attempts the tricky gymnastic moves.
She says: “I’ve had some mad thoughts and visions of smashing my face like something out of You’ve Been Framed.
“Doing a cart-wheel on the beam was very daunting. You practise it on lines on the floor beforehand to work it all out.
“But it’s a mental thing for me – going headfirst towards a narrow beam which you could fall off and hit your head. You have to get over the fear and stop imagining horrible things.”
The gymnastic routines force the pair to get up close and personal – so how has Amelle, who has a long-term boyfriend, found it? She admits: “It was a shock to realise how physically close we’d be.
“The first time we did our floor routine, he told me to kick up into a handstand and the next thing I know he’s grabbed me and my head is near his crotch.
“I was like: ‘Oh my God, oh my God!’ But you have to forget about that because you have to think about what you’re doing.
“I’ve got a boyfriend so there won’t be any romance for me but I can see how it happens. If you have that connection and you’re with that person every day, I can totally understand how some people have fallen in love.
“I’d be lying if I said it didn’t take a minute for my boyfriend to get his head around it as it’s strange seeing your partner being held by another man in such close contact.”
The floor routine Amelle has learned certainly sounds gruelling – with one move called the Back Breaker.
“All the gymnasts call it that because if you make one wrong move, that’s what can happen,” she says.
Away from Tumble, Amelle says she’s not sure whether the Sugababes, which also feature Heidi Range, 31, and Jade Ewen, 26, have a future, but if it is really over, she hopes to with one final hurrah.
“It would be nice to say one final goodbye with an album or at least something to mark it,” she says.
“I don’t know myself what’s going on so I’m just focusing on other things.”
One of those other things is her solo career, and Amelle is shortly to release her new single Summertime.
“It took me a while to find out what I wanted to do. And this single ended up being a very jazzy, reggae, summer song that should make you smile. I actually wrote it about my sister and no-one really noticed.
“It’s a very dear song to me. This is genuinely me and what I do. I’m not trying to be anyone else, and I don’t think you should lie to an audience.
“In the Sugababes you are unknowingly moulded a certain way. I remember being told not to smile quite a lot. But I actually smile very regularly. I don’t want to play that game any more.”
Tumble starts tomorrow on BBC One at 6.30pm. Amelle’s single Summertime is out next month.