IT was unlike Strictly Come Dancing’s Mr Nasty, Craig Revel Horwood, to use the F-word so early in the series. “Carry on like that, da-ahling, and we could see you in the final,” he drawled, as a gobsmacked JJ Chalmers and his professional partner Amy Dowden stared in disbelief.

Chalmers is the former Royal Marine who is carrying Scotland’s hopes on his shoulders in this year’s Saturday night glitterfest. Thank goodness he can dance.

“Well, I hope so,” he says, with a laugh. “’I’m very grateful to everyone who has voted so far. It was incredible to get a comment like that so early in the competition, but I am not thinking that far ahead, not at all.”

He says, seriously: “Every Monday morning, I’m starting from scratch. You can have the best Saturday night, and the most brilliant foxtrot or wonderful jive, but you have to forget those highs when you get back into the training room for the next week.”

He pauses. “But it is good to hear nice comments like that,” he adds. “Makes you think all that hard work and effort is paying off after all.”

Hard work comes naturally to Chalmers, who is an Invictus Games medallist and TV presenter.

He agrees he has always been ‘driven’ – quick to be hard on himself, and unforgiving of his own mistakes. Last Saturday, he and Amy Dowden narrowly avoided being knocked out of the show, having ended up at the bottom of the table following a low-scoring jive.

“I can’t put into words what this means to me,” he tweeted after being saved by the public vote. “Not the scores I’d hoped for, but ultimately a response beyond my belief.”

During a break in training for tonight’s quick-step, Chalmers is equally earnest. “I have always been grateful for the opportunities which come my way,” he says. “These are big, shiny opportunities, and I would never take anything for granted. My time in the military taught me that.

“I’m determined to make the most of every opportunity. And everything about this show is amazing. To learn a new skill, from someone as brilliant and as lovely as Amy, is just fantastic. I’m having the time of my life.”

This year’s Strictly is a Strictly like no other. Celebrities and professionals have left family behind to ‘bubble up’ with each other for the duration, and thanks to Covid restrictions, there is no longer a live audience (apart from the crew, who are providing the studio atmosphere with admirable gusto each week). Hosts Tess Daly and Claudia Winkleman remain socially distanced throughout, and the judges perch on sparkly, individual podiums rather than sit side by side. There is absolutely no hugging.

Already, one couple has had to bow out. Boxer Nicola Adams had to leave when her partner Katya Jones tested positive for Covid-19.

Despite all the changes, viewing figures are on the up, with regular highs of more than 10 million.

For the teenage John James Chalmers, growing up in Dunfermline the son of a church minister, Strictly was never on his radar.

He became a craft and design teacher in Balerno in Edinburgh before signing up full-time to the Royal Marines, which he had joined as a reservist in his teens.

In Afghanistan a year later, his life changed forever when he was caught up in a bomb blast which killed two of his friends.

His injuries, to his face, chest and body, were horrific. Chalmers woke up in a Birmingham hospital a week after the explosion, with his arm temporarily grafted to his stomach to keep it supplied with blood. He had dozens of operations, including one in which doctors took muscle lining from his leg and used it to replace a severed tendon in his tricep. He lost two fingers, and his abdomen is severely scarred.

Chalmers feared he would never walk again, and months of rehabilitation followed. It was while watching the 2012 London Olympics that he felt inspired to take up sport again, a path which led him to the Invictus Games and a friendship with founder Prince Harry, the Duke of Sussex. (The Duke popped up in last week’s Strictly, in fact, taking a rise out of his friend’s fake tan and shorts, before congratulating him on his determination and "amazing journey".)

The Games ignited Chalmers’ interest in sport and a desire to try presenting. Roles including Channel 4’s Rio de Janeiro Paralympics coverage, BBC’s London Marathon and The One Show followed.

“I think there always has been a performer inside me, somewhere,” he reflects. “At school, I struggled with dyslexia until I got the right support, and that had a big impact on me. I could never express myself in writing, but I was always comfortable standing up and speaking in front of my classmates, or the whole school, and I could always get my point across. It never fazed me – I became a bit of a class clown as a result.”

His desire to teach grew out of a long-term love of learning. “I loved teaching, it was fantastic to work with young people and to help inspire them,” he says. “I suppose presenting is similar to teaching in a way – it’s like standing in front of a big classroom, imparting information and hoping that your enthusiasm helps to shape someone’s views about sport, or dancing, or whatever it is.”

It is a ‘difficult world’ for teachers at the moment, he agrees. “My brother and sister-in-law are both teachers and it’s tough just now, absolutely,” he says. “They are doing a fantastic job.”

Despite his ordeal in Afghanistan, Chalmers says he has never regretted joining the Marines – something he did, he says, from a ‘sense of service’.

“It also gave me the opportunity to be part of this amazing brotherhood, this support network which lasts for the rest of your life,” he says. “The guys and girls I served have always had my back, and they continue to be there for me. They share in the highs and the lows. You go through it all together.”

Training, and learning what his body can and cannot do, has been eye-opening, he says, but Dowden’s choreography takes all of that into account.

“Amy already knows me so well that she choreographs each dance around what she knows I can and cannot do,” says Chalmers. “It’s a physical and mental test each week.

“I live with a constant level of pain, day to day, that’s just the reality of it.

He adds: “I do still encounter frustrations. Normal, everyday things, usually – little things, like not being able to turn a door knob, for example.

“I mean, I was a Royal Marine. I could kick a door off its hinges in seconds – and now it’s a struggle to turn a door knob? It is frustrating.”

Chalmers says his surgeon watches the dances ‘from behind his fingers’.

“This is the man who essentially chopped off both my arms and put them back together again, in the hope that it might save one of them,” says Chalmers, calmly. “I was very lucky that, in fact, both of my arms were saved.

“He essentially rebuilt my elbow, so the idea that he is watching me do all these moves, flinging a cape around, catching Amy in one arm, and whatever – it’s amazing.

“Many people worked unbelievably hard to get me to this point, the surgeons, my wife – everyone. So I’m doing this for them, to show them it was all worth it.”

Chalmers and his wife Kornelia met at university – he was a student at Edinburgh, she was at Napier. “We ended up in the same friendship circle,” he explains.

They married in 2015 and now live in Dunfermline, with their daughter, Hayley, four and one-year-old son, James.

“It’s hard to be away from them, but my wife has the hardest job of all,” says Chalmers. “I get to be here, at Strictly, while she is at home with two kids, essentially being a single mother and doing absolutely everything to allow me to pursue my dreams.

“It’s relentless. There is no glitter for her, other than the stuff my daughter makes a mess with in the living room. But she is the first person I turn to if I’m having a hard time, always.

“After Aghanistan, she did everything for me.”

In an interview with The Herald’s sister title the Glasgow Times, amputee and Finding Your Feet charity founder Dr Corinne Hutton hailed JJ, and fellow celebrities like Hollie Arnold and Marc Elliot (appearing respectively on I’m A Celebrity and The Great British Bake Off) as ‘poster boys and girls’ for people with disabilities.

“It’s great to see, but I’d really like to get to the point where no-one bats an eyelid – where it’s just not that unusual to have people with disabilities on prime time television” she said.

Chalmers relates to this ‘100 percent’, he says. “I’m the fourth person with a physical disability to appear on Strictly Come Dancing,” he points out. “That’s not box-ticking. It is about realising that a programme which is as inclusive as possible is simply a better programme.

“If people with disabilities were formally recognised as a ‘minority group’ it would be the biggest minority group in the world – something like 20 per cent.

“People like me need to turn on the television and see people like me, otherwise they won’t be inspired to do it."

STRICTLY SCOTTISH

Scotland has had its fair share of sparkling moments since the series began in 2004. Here are some of the best (and worst).

JOE MCFADDEN: All hail the Heartbeat and Holby City hero, who took the glitterball trophy with partner Katya Jones in 2017. He was the kind of contestant diehard fans love – not that good to begin with, but properly improving along the way, and cheery with it. He went on the obligatory 'journey' and we loved him for it.

SUSAN CALMAN: Who can forget superhero Susan the Glasgow comedian, resplendent in full Wonder Woman costume, leading Kevin Clifton on a merry dance through series 15? If it had not been for that McFadden, she might have won it. Well, probably not, but Susan was a fan favourite.

CAROL KIRKWOOD: She shone like a sunbeam, everyone’s favourite weather presenter, when she appeared in the 2015 series of Strictly. Despite being partnered with reigning champion Pasha Kovalev, however, Carol failed to make much of an impression and drifted off in 10th place.

KENNY LOGAN: He was the first person ever to wear a kilt on Strictly, an event that has not been repeated since. For good reason, probably. Standing proud over partner Ola Jordan at the end of his powerful Paso Doble in series five, viewer were grateful she had her hands over her eyes.

LULU: Singing legend Lulu did not have the happiest of times on Strictly. Cheek to cheek with New Zealand professional Brendan Cole, she blamed her exit from the ninth series on his being too tall. Tension crackled in the air whenever they were together. Afterwards, he simply said they didn’t ‘gel’.

CAROL SMILLIE: Way back in 2006, model and TV presenter Carol Smillie was partnered with Matthew Cutler, and they made it almost all the way to the quarter final. After their Viennese Waltz, judge Arlene Phillips mysteriously described Carol as “a bit like a science teacher.” Ouch. Elegant and talented, Carol was our first real chance of a Scottish winner.

THOM EVANS: This was a classic Strictly shock exit, when handsome Glasgow Warriors rugby player Thom Evans found his final dance with partner Iveta Lukiesuto in series 12 too much of a cha-cha-challenge.

RORY BREMNER: His quickstep was lovely, but, like Thom, it was the cha cha which did for him in the end. Departing in week four of the 2011 series, in which he partnered Erin Boag, the impressionist left with the words of head judge Len Goodman ringing in his ears. “You’re like the government – there’s a lot going on and not all of it is good….”

JUDY MURRAY: Strictly superfan Judy was over the moon to be on the show she had watched avidly for more than a decade, dancing with King of the Ballroom, Anton du Beke. Sadly, her tennis footwork skills did not translate to the dance floor, and she lasted only until Blackpool. One of the kinder comments from the judges described her as having something akin to ‘rigor mortis’.