Judd, who has been paired with Aliona Vilani for the competition, previously appeared in a special edition of Strictly Come Dancing for Children In Need.
However, he explained that the show's producers have now tried to make sure that he will not be too far ahead of the other contestants by giving him reduced rehearsal time.
"We're not allowed to start rehearsing for a week," he explained. "The other guys start next week - we're not allowed to start until a week after."
© BBC
Judd, who admitted that he tried to get fit before the competition began, joked that Vilani has already given him some exercises to do by himself to prepare for their rehearsals.
"I asked if there is any advice for during that week, like stretching," he said. "And she said, 'Look in the mirror and practise your faces'! Can you imagine doing that at home? I've got my faces down."
Judd also revealed that his fellow McFly bandmates have been "really supportive", saying: "They know it's hard. We're not dancers. It's awkward, you feel embarrassed, and you've got to have the confidence to let yourself go. The guys are totally understanding. They're being really encouraging, which is nice."
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