She said: “It’s the jive. The dance I struggled with the most when I did the first series was the jive because it’s so full-on.
“My cardio fitness isn’t what it was before. It’s still alright, but half-way through the dance, he’s going, ‘Keep going!'”
Gemma recently shared on Instagram her fitness journey since giving birth.
She shared a series of photos of her working out on a bike and encouraged her followers to not feel disheartened when it comes to getting back in shape post pregnancy.
Her caption included: “This is for anyone who (like I was) are told what they are no longer capable of because they’ve had a baby. You were someone before you became a mum. Remember that!
“Some people were shocked that I didn’t “snap back” straight away.”
The Strictly Come Dancing Christmas Special airs on BBC One at 4.40pm.