Busy solicitor and mum-of-one Claire Wheeler wanted an extreme challenge to raise cash and awareness to combat a little-known disease which kills children.

The challenge she chose was so extreme it took her six months to pluck up the courage to sign on the dotted line.

You’ve heard of Iron Man. Well, meet Claire Wheeler – Iron Mum.

This Saturday Claire, 36, of Hepworth, will take part in the Edinburgh to Ben Nevis ‘City to Summit’ ironman distance triathlon.

Claire, who has an 18-month-old son Felix, faces the challenge of her life.

She must swim 2.4 miles across the Firth of Forth, cycle 112 miles through the Scottish Highlands and then run a full 26-mile marathon distance up Ben Nevis and back down.

And all three must be completed within 18 hours or the challenge ends in failure.

Failure, however, is not an option for Claire.

“It’s a real test of endurance,” said Claire.

“To be honest I am terrified. What really terrifies me is not being able to complete it in time.”

Claire has devoted the last six months to training for a test of mind, body and spirit.

Family time with Felix and husband Paul, 36, has been put on hold until after the weekend.

With a demanding job as a professional indemnity lawyer in Manchester and an equally demanding young son, Claire’s spare time was precious.

But she managed to squeeze in two or three hours of training every night and another five or six at the weekends.

So what is the cause that has left Claire so driven that she has given up so much to put her body on the line?

The inspiration is a little girl called Anna Lucy May Lewis, the daughter of her close friend Jess, who died aged 14 months.

Anna had been a happy and healthy baby born on February 9, 2011.

She brought joy to her family but the following January became seriously ill.

Two months later she was diagnosed with Alpers’ Disease, a rare mitochondrial disease – or inherited cell disorder – for which there is no treatment or cure.

Anna was in hospital for 11 weeks and never came home. She died on April 1, 2012.

Claire, who met Jess, 37, at university in Durham, was devastated.

So when Jess embarked on a fundraising campaign for specialist research equipment for the hospital where Anna was treated, Great Ormond Street in London, Claire was determined to do all she could to help.

The fundraising target of £85,000 was huge and demanded the extraordinary.

Step forward Claire and her iron mum challenge.

“My husband Paul found the City to Summit on the internet,” said Claire.

“I wanted extreme but I wasn’t sure I wanted it to be that extreme!

“It took me six months to agree to do it but once I did I was committed.”

Claire has always kept herself fit and said: “I’m a decent swimmer and an all right runner but I hadn’t ridden a bike in a long time.”

Claire took part in the Holmfirth Triathlon last year but the distances involved meant it was merely a training session for the big one.

As a warm up she completed the Brian Robinson Challenge Ride, a 75-mile bike ride over Holme Moss.

“It was horrible and I hated every minute,” said Claire. “I got blown off my bike in Meltham but I completed it in under six hours and it was a really good training ride.”

Much of Claire’s bike training took place on a turbo trainer in the garage during the winter months.

For six months Claire’s day went something like this. She left home for work in Manchester at 6.15am and was back for about 7pm, just in time to see Felix for 10 minutes before putting him to bed.

Paul cooks dinner while Claire gets down to some serious training on the turbo trainer for at least two hours.

It’s then food and bed by 10.30pm before getting up early the next morning to do it all again.

Family time at weekends, too, has been sacrificed and Claire said: “I couldn’t have done it without Paul. He has been amazingly supportive.

“It has been difficult fitting in a full-time job, a young child and the training but you just have to keep organised and disciplined and not lose sight of what it’s all for.

“There have been times when I thought I couldn’t do another hour. I was in the garage cold, hungry and tired but I’ve had to keep going.”

Claire had pangs of guilt about leaving Paul and Felix at weekends but said: “The end is in sight.”

Felix will stay with his grandparents this weekend while Claire and Paul head to Scotland.

Claire hopes her exertions and sacrifice will earn £10,000 and push the fundraising total for Anna’s appeal to within touching distance of the £85,000 target.

“While the money is important so is the awareness for a disease I had never heard of,” said Claire.

“More children die of mitochondrial diseases in the first 10 years of life than die of childhood cancers.”

To donate go to www.justgiving.com/Claire-Wheeler2