Katie Price says 'I'm A Celebrity... Get Me Out Of Here!' was a "holiday camp" compared to 'Celebrity SAS: Who Dares Wins'.
The 41-year-old star admitted there were some big differences between ITV's reality show and Channel 4's gruelling boot camp with former soldier Ant Middleton leading the charge.
She said: "The jungle was a holiday camp in comparison - there was definitely no time for any romance."
The Bushtucker Trials seemed a world away for Katie, who had to walk backwards down the side of a cliff with the other recruits.
Reflecting on the challenge, Katie added: "O.M.F.G - you are joking right?
"I said to myself, 'Pull your s**t together, Katie, you've got this'. I wasn't going to be left on that cliff alone!"
As well as chief instructor Ant, Katie and her co-stars - including the likes of Joey Essex, Brendan Cole, Lauren Steadman and Tony Bellew - were put through their paces by his team of directing staff.
The model admitted she struggles with authority, but had to make sure she kept calm and composed without answering back.
She explained: "I don't like my mum shouting at me, let alone someone I barely know, in my face.
"I wanted to give it back, that was a challenge in itself. I had to sow respect to my commanding officer."
Katie managed to bite her tongue and keep her "ego" - and bladder - in check as the cast came to terms with the "terrifying" experience.
She explained: "[The team were] amazing, terrifying, hard, in your face. It was scary.
"There was no place for egos or toilet breaks - this was full-on, nothing edited, gritty as it happened.
"They were, however, checking in on us all the time to ensure we were coping. This isn't for the faint hearted."