THE commands are the kind that might be more likely to be heard at a church hall exercise class than a genteel choir rehearsal: "In and out! Up, down and... relax."
Shoulders are energetically rolled backwards and forwards, arms are stretched - legs too - and the 60 or so members of the Edinburgh Singers, ages ranging from early 20s to 70s, puff and pant their way through a string of breathing exercises.
"It is a bit like a workout," laughs Liz Fuggle, a young architect who, when she's not designing buildings is helping to create a wall of sound in the choir's Alto section. "Some people go to the gym and we go to choir practice."
It doesn't seem like most people's image of a choir preparing for one of the biggest nights in its 50-year history. But putting the singers' vocal talents through a string of energetic pre-performance physical jerks - even down to pulling strange faces to get the facial muscles limbered up - has been a major element in a dramatic turnaround in the choir's recent success story.
It all reaches a climax tomorrow evening when the choir performs to its biggest audience to date, on BBC1's Songs of Praise.
"It's a huge platform for us," agrees the choir's 24-year-old musical director Dominic Peckham - a trained opera singer and former conductor with the National Youth Choir of Great Britain.
He is credited with helping transform the Edinburgh Singers from just another ensemble to contenders for next year's BBC Choir of the Year title.
"I decided at the start to take a very energetic approach to everything we do, and that includes our very wacky warm up techniques," explains Dominic.
That's why the first 15 minutes of rehearsals and before performances are taken up with what Dominic describes as "a mini-workout" - aimed at limbering up the voice and body for the stresses and strains of singing.
Jenny Rice-Jones, 29, an engineer, joined the choir five years ago and said Dominic's arrival as musical director had given the choir a boost. She adds. "As soon as Dominic joined us for a rehearsal it was clear what he could do and how good he was."
At 26, Liz is among the younger talents within the 95 names on the choir's books.
Originally from Glasgow, she joined the choir two years ago after graduating in architecture from Edinburgh University. "I had sung in the school choir but it has been the direction from Dominic that has improved my singing greatly. We've all come a long way in the last couple of years."
The singers have travelled a long way too. Earlier this year they toured Tuscany for four days, performing three concerts in the splendour of Florence, Moticatini and San Giminano. Each concert was full to capacity and each received a standing ovation.
The choir was already busy preparing in June - at the time of its Edinburgh summer concert - for what will be its next performance: its annual sellout Christmas recital in the drama and atmosphere of Greyfriars Kirk.
The programme of up to 20 Christmas themed pieces may sound effortless on the night, but it will be the result of weeks of hard work, finely tuned rehearsing and, of course, lots of arm waving and leg shaking as part of Dominic's energetic warm-ups.
"People might think choirs are quite serious but it's not like that," said Liz. "We laugh a lot, and it's a wonderful, lovely feeling to perform together."
There's even more to it than that, however, says fellow choir member soprano Ailis Sandilands. She joined the Singers two years ago after qualifying as a doctor and finally finding herself with time to commit to her passion for choral singing. "It's been a great social experience," she says.
"It's been a great way to meet people from different social groups - people you'd probably not meet otherwise."
The ensemble is certainly enjoying an unprecedented revival. Fired with Dominic's enthusiasm, the choir has tackled everything from the classics in the form of Beethoven's Mass in C Major and Vaughan Williams' Mass in G minor - dramatically contrasting pieces that wowed the audience at the Edinburgh summer concert.
But it's the potential four million-plus audience that the choir will have on Sunday evening that is top of Dominic's agenda for the time being.
"It's such a great platform for us," he says. "
It's been a wonderful year for us - and we're looking forward to an even better one next year."
• Songs of Praise is on Sunday, on BBC1 at 5.15pm. For more information, visit: www.edinburghsingers.org.uk