Katie Price has said she feels like she let herself down on Celebrity SAS: Who Dares Wins.
The reality TV star and former glamour model, 41, underwent breast reduction therapy before appearing on the Channel 4 show.
Price said while she was “strong” mentally, her body was not ready for the gruelling reality show hosted by chief instructor Ant Middleton and his team.
She said: “I think a lot of people would know that mentally I am strong, just by my past and what I have been through …
“But it it was just physically my body wasn’t ready for a lot of the things I was put forward to, because that’s just due to my stupidity of going smaller surgically.
“But apart from that I am a strong person anyway. When you get an interrogator going at you, even thought you know it is fake, although it is a show, it is not supposed to feel like a show. It feels like reality.”
Price, who has been married three times, including to Peter Andre, credited the programme with improving her mental health.
“I was going through a bad time mentally before I did this show,” she said.
“You will all find out what was going on.
“Since doing the show, for my mental health and stuff, being fit, I am actually so much fitter now than when I did the show.”
She added: “My only big thing is that someone else had been offered the place instead of me because I feel like I let myself down.
“What I mean is because of my boobs physically – you will see some of it – that I shouldn’t have done it. I lied to myself.
“But since the show it has made me think … I am much fitter now that, if I ever got that chance again, I would love to do the show again.”
Price said during filming she faced a challenge that reminded her of a childhood trauma, although she did not reveal what it was.
Among the other celebrities taking part were reality TV star Joey Essex, TV presenter Helen Skelton, former footballer John Fashanu and Hollyoaks actress Nikki Sanderson.
Price praised the group for welcoming her without judgment or an agenda.
She said: “It is nice to get away for your own time and not people relying on you for everything all the time.
“It’s all about team effort, yourself and just meeting different people and stuff like that.
“And not being judged, not being used. To me it’s like people talking to me because they want to talk to me. They have got no agenda.
“They are not getting anything out of it. It’s not like we are going for dinner and they expect me to pay. You are in there together.”
Celebrity SAS: Who Dares Wins returns to Channel 4 soon.