Olly Murs has wowed fans by sharing before and after images of his body transformation.
The first shot showed Murs in underwear before he shed weight and toned up, while the second was of him looking far more muscly.
"Put ya positive pants on and tackle the day," he told his fans.
Murs - who has battled a knee problem and had to have an operation this year - went on: "Facts are my knee won’t ever be back to normal but it won’t stop me from bouncy around on stage or in life.
"You know who I am and I ain’t stopping for no-one!
"Hope ya ready for the madness cos I am."
The star, who got engaged to his bodybuilder girlfriend Amelia Tank this year, was inundated with praise from his celebrity friends after he shared the pictures.
Vernon Kay quipped: "Kinda relate to the exasperated look in the first pic on the left… Hard work pays off!!"
And Ronan Keating joked: "Yea mate. Well done. Love it. What tan do you use. Asking for a friend."
"Jeeeeez," posted Amanda Holden.
Joe Wicks wrote: "Man is in shape. Get up there boy."
Fan said the Troublemaker singer looked "unreal".
"Cracking results!" one remarked.
"Literally lost five years and gained back those abs," said another fan.
He went on to have a successful pop career and presented spin-off show The Xtra Factor with the late Caroline Flack.
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