In a post uploaded to Rio’s Instagram account, the former footballer could be seen doing press ups with Kate on his back.
As the 39-year-old pulled of the impressive move, Kate could be heard screaming as she attempted to balance herself.
The former The Only Way is Essex star giggled away as she shouted out: “Go on boy!”
As Kate, 26, rested on Rio, the beauty’s ample cleavage spilled out of her gym top.
Rio captioned the clip: “Morning workout with this loon!! #gym #gymcouples.”
However, his 2.8 million followers weren’t completely focused on their workout as they were more blown away by Kate.
One person commented: “Took me a while to even notice Rio.”
“Like anyone was looking at Rio on the press ups,” said another.
Another fan gushed: “Love you guys, you have so much fun together.”
Rio and Kate began dating last year, after the sports commentator tragically lost his wife Rebecca Ellison in 2015.
And earlier this week, Kate appeared on This Morning where she spoke about taking on the step-mother role to Rio Ferdinand’s three children, who he shares with Rebecca.
During her chat with Holly Willoughby and Phillip Schofield, Kate insisted her priority was to keep the memory of Rio’s late wife alive.
She said: “You only have one mum, their mum is irreplaceable. There’s a special room in the house, for their mum and their nan – they might do homework there for example.
“We always celebrate Rebecca’s birthday, we all go to cemetery together. We do talk about their mum, I know a lot more about her than they think.”
Rio’s three children have also brought up the idea of marriage between Kate and Rio and haven’t stopped pestering them about when they’re going to have a new sibling.
Kate said: “I couldn’t imagine the kids would talk about it before!
“At the school gates, at first they said that’s my aunt, then that’s dad’s girlfriend, then that’s my stepmum.
“And now they say on daily basis, ‘When are we having a brother or sister?’ It’s really lovely!”
She added: ”They’ll say ‘when do you want to get married, we want to be bridesmaids’.”
This Morning continues weekdays on ITV at 10.30am.