The new gymnastic series kicks off on Saturday night and the former Eastenders actor is said to be impressing the show's coaching team after just six week's training.
An insider told the Daily Star newspaper last week: "John was by far the best and showed some real skill at gymnastics.
"He is a gym junkie and even used to hold fitness classes for the stars of EastEnders during breaks in filming.
"He is very competitive and wants to be the best so they have a real battle on their hands - and feet!"
It's pretty impressive going as in between training sessions, John has been working on a debut album.
After celebrating 30 years in the business last year, John this week announced that his record ‘Dames Dudes + Cowboys Too’ – will be released September 15th on Big Hand Recordings.
The album will feature a selection of both his favourite artists’ songs and some original tracks.
"I wanted each song to sound and feel completely new, to have a life of their own," he said.
Tumble starts this Saturday night at 6:30PM on BBC One.
Browse pictures of the Tumble celebrities below...