A 36-year-old man faced the most "gruelling physical and mental" challenge when he took part in military style assault course for a BBC show.

Alex Lacey from Bushey has taken part in the BBC2 programme Special Forces - Ultimate Hell Week.

The show, which will be presented by Freddie Flintoff - a former England cricketer, forces 29 men and women to face the ultimate endurance test over 12 days.

Mr Lacey made it to the final for the show out of thousands of applicants. He said: "The process was gruelling and you are massively taken out of your comfort zone. They initially selected 50 and then for 48 hours we were put through our paces physically and mentally and from that they selected the final 29."

The BT telecommunications engineer said he decided to apply for the show because he generally enjoys keeping fit and takes part in obstacle course races on a regular basis.

He said: "I started doing the races after I lost my Dad in 2003 to brain tumour - I wanted to make him proud of me. I have done fundraisers and a campaigns to raise money for the course, but I do it mostly to remember him and make him proud."

Mr Lacey said on average he does an obstacle course race on weekly basis.

But added: "This BBC show is by far the toughest challenge I have ever done. It is the most gruelling physical and mental challenge where you are pushed well above your limit and basically have to search into your soul to survive.

"If you think of your worst nightmare and times that by four, that give you an idea of what we went through."

Mr Lacey was competing against people such as ex-professional boxers and world champions in the final.

Over the 12 days people from special forces including the SAS and navy took it in turns train the 29 people.

Mr Lacey added: "Each day got harder and harder - the challenges aiming to break us down. We were also sleep deprived and not had much food - it was all about just surviving.

"But it was the best thing I have ever done."

Special Forces - Ultimate Hell Week is a six part show and the first episode will be aired on Sunday at 9pm.