Working up a sweat alongside each other, the boys looked pleased to be reunited and we've no doubt they had plenty to catch up on!
Taking to Instagram mid-workout, Mario snapped a selfie with Arg for TOWIE fans to see.
Impressed with his friend's recent transformation, Mario took the time to congratulate Arg on all his hard work so far. Alongside his photo, he said: "Look who I found in the gym...! Must say he is looking the best I have ever seen him! Well done mate!"
He certainly is looking good!
Last year, Arg was suspended from TOWIE after his behaviour caused some concerns and he later checked himself into rehab over Christmas.
On his return home, the reality star has been spotted putting hours in at the gym and the results of his healthier lifestyle are definitely starting to show.
So much so, that Arg is looking like a new man, don't cha think?!
This weekend, the new series of TOWIE is set to air and ahead of the show's return, many are wondering if Arg will make his comeback - including his ex-girlfriend Lydia Bright.
When quizzed about her former flame on This Morning earlier this week, Lydia revealed she hopes Arg will soon make his TOWIE return.
"We're all hoping and praying he'll come back at some point during this series," she said.
Her co-star Elliott Wright added: "He was in a bad place and he's come through it really strong. He's working really hard, I'm really proud of him."
Meanwhile, Arg has said he too hopes he can join the cast again, thanking fans for their continued support.
Reveal asked a TOWIE rep if Arg would be making an appearance this series, they told us: "No decisions have been made yet."
TOWIE returns this Sunday 22 February at 10pm on ITVBe.
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Watch the trailer for TOWIE's new series here: