The sporty pair were revealed on The One Show today (August 27) on BBC One.
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When asked if she had any dancing experience, Gallacher said: "Not since I was about ten. I used to do loads of ballet and tap… It is very new to a lot of us."
Thomas went on to say that he often likes to try his hand at breakdancing when attending stag-dos, but described himself as a 'dad dancer'.
He also said that his biggest challenge will be controlling himself and dealing with the pressure of the live shows.
Gallacher is best knows for presenting shows such as Gladiators, Sky Sports News and Kirsty's Home Videos, while athlete Thomas found fame as