Taking to Instagram to post a rare video of himself getting a sweat on, Piers could be seen giving his biceps a serious workout at Roar Fitness in Central London.
As he completed several reps with large weights, the father-of-four wasn't afraid to show his 1.7 million followers his 'workout face'.
WATCH: Piers Morgan bares his muscles at a London gym in new workout video
"Everyone pities the weak… jealousy you have to earn," penned Piers, relaying a quote from Arnold Schwarzenegger.
Wearing a blue sports polo, black Adidas shorts and a pair of black Nike trainers, Piers looked ready to take on the reps as he pushed through his killer upper body workout.
Piers' workout technique received mixed reviews from fans, who rushed to reply to his Instagram story – and he got some hilarious responses.
"Is that your sex face Piers?" asked one fan, whilst another joked: "Are you getting ready for Love Island?"
"No, sadly I have brain cells so I don't qualify," jibed Piers, who has notoriously slammed former Islanders for competing on the hit ITV show.
"Can't you just practice picking up your wallet? Surely it weighs more?" teased a third, to which Piers sarcastically replied: "No, it's too heavy."
This may be one of the first times Piers' followers have ever seen him working out in a gym, but that doesn't mean the celebrity journalist doesn't enjoy exercising in one of his own homes.
Piers recently shared a photo of his country retreat in the East Sussex village of Newick, featuring a large outdoor pool.
Framed with cream concrete tiles, a brown wooden fence and green bushes and trees, the pool area also has a wooden outdoor dining table with coordinating chairs and a cream parasol for Piers and his family to enjoy al fresco meals - when he's not racking up the laps in the pool!
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