A PERSONAL trainer faced the challenge of a lifetime when she took part in a gruelling SAS training TV show.

Sharissa Harfield went from her Tadpole Garden Village studio to the dizzyingly-high mountains of Chile after becoming one of a dozen women picked to be part of Channel 4's SAS: Who Dares Wins.

In an episode which aired on Sunday, ex-Special Forces soldiers including Ant Middleton put her and the other recruits through a recreation of the SAS selection process.

At one point, they had to submerge themselves in the water of a frozen lake and were given a stern telling off for getting their bras wet.

Sharissa said: "Ant really means business,, it was brutal, the cameras were on us 24/7 and it's scary enough going on TV let alone being chucked in freezing water, but I took it all in my stride.

"We were up in the mountains and the altitude was horrendous, I was sick straight away and some of the other recruits were taken to hospital.

"I was ill in hospital three weeks before we flew out but luckily the doctor said I was well enough to go on the show. When I was up there, I kept having heart palpitations and the medic checked my heart rate every half an hour.

"Though sometimes I couldn't breathe, I didn't want to give up, I said I'd keep going to the end, and I learned a lot about myself, but I had to listen to my heart and voluntarily withdraw..

"Ant tried to make me stay and said that I was far from the weakest person there, which was nice, but I had to go. I was unwell for weeks afterwards, but I'm alright now."

Sharissa estimates that she spent just over 24 hours on the show and, though slightly disappointed that she didn't make it to the end, she's proud that she was tough enough to be chosen for it in the first place.

This was the first time that women were allowed to apply for the series, so Sharissa began the long application process last summer.

She added: "This was the first stamina challenge I'd taken on and I think any others after this will seem pretty easy by comparison.

"I always watched the show and thought that I'd love to give it a go. I'd done a few bikini fitness competitions but nothing like that.

"There was a fitness test, I was interviewed in front of a camera, then had another fitness test and spoke to a psychologist.

"After that, it was a bit of a waiting game, I had to keep it quiet and took two weeks off work without telling my clients why, and I didn't know where I'd be going, it was all very secretive.

"My close family knew but no-one else did until the show aired, my friends said I was really brave and they were very proud of me."

Sharissa moved her personal training business from Surrey to Swindon after returning from Chile.