Mike Tindall opened up about how his marriage to Zara, saying it "is not that easy" in a new programme called Grand Slammers.
The I'm A Celebrity star appeared on the TV show on Wednesday night, where he went inside HM Prison The Mount, a Category C men's prison in Hertfordshire, for a unique challenge.
In the programme, Mike and his fellow co-stars used their sports skills to train a team of prisoners to be strong enough to compete against their rivals, the Australians.
During one scene, Mike opened up about his marriage of 12 years with Zara and life after playing for England in the Rugby World Cup in 2003.
Mike and Zara tied the knot in 2011
Mike competing in the Rugby World Cup in 2003
He said: "Everyone thinks that just by marrying Zara that means it's all fine and dandy… But that doesn't stop the fact that you need a job.
"And it's not that easy, you know - you get quite institutionalised into rugby, it's a way of life and you leave the game and that's not there.
"I don't think you can ever sort of describe when you're so used to being around that many people, and understanding, because of it being ingrained in you, where you fit in to then not being that person.
"Zara would say if she was honest it was probably a year it took me to figure out what I was, who I was going to be."
Mike Tindall and Zara Tindall at King Charles's Coronation
Mike and Zara are known as very down-to-earth royals
Mike officially retired from rugby in 2014, however, the athlete has opened up about struggling to find work after his sports career.
He continued during his interview on the ITV programme: "You've got to then go carve where the next path is - you can never replace going to work with 35 of your best friends every day."
Several other athletes joined Mike in the two-part documentary, including Martin Johnson, Jonny Wilkinson, Lawrence Dallaglio, Phil Vickery, Jason Robinson, Will Greenwood, Ben Cohen, and Matt Dawson.
The second part of the ITV documentary will air tonight at 9pm on ITV1 and ITVX.
Mike opened up about his marriage during his new ITV programme