An Iraq veteran from Dereham is hoping to land a place on the popular Channel 4 television show SAS: Who Dares Wins.
Lloyd Thompson attended an audition for the show at Camden, London on Saturday.
He is expecting to hear if he has made the cut within the next fortnight.
The programme sees five ex-special forces soldiers put recruits through a recreation of the SAS selection process.
The experience is designed to put contestants through the ultimate test of their physical and psychological resilience.
The audition featured an interview and various fitness tests.
Mr Thompson, 41, known locally as Big Lloyd, said: 'I'm hooked on the show and I've always enjoyed pushing myself and seeing how far my limit is.
'Twenty five people get selected and if I get through I'll be really looking forward to it.
'I'll be a fair bit older than most people in the show and, weighing 18 stone, will be a lot bigger as well.
'But I've always been mentally strong, which is half the battle.
'I believe I can go all the way and win it.'
Mr Thompson, who works as a security guard in courts, is a part-time fitness instructor.
He has previously run military-style boot camps in Dereham to raise money for the Dereham branch of the Royal British Legion's Poppy Appeal.
He served three tours of Iraq and has represented the British Army at boxing and rugby.
If Mr Thompson does get picked for the show he will go away overseas, to a location not yet known, for filming at the end of September.
People will see him pounding the streets of Dereham and Scarning in coming weeks as he continues his training for the show.
Mr Thompson said: 'I've built up a lot of muscle, so I'm working on cardio at the moment as there will be a lot of running to do on the show. It won't be easy to carry my 18 stone frame around - some of the guys on there will be more like 12 stone.
'I know the whole experience will be mega hard, but I just want to inspire people and encourage others to go out and really achieve something.
'If I get in I hope to raise money for some sort of charity - maybe a cancer charity, through the show.'
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