"Aaah!" mutters a teenage boy, grimacing as he struggles to hold a squatting position before falling backwards laughing. A classmate takes a break, blaming a sore knee brought on by "too much exercise", while a third pupil, dragging his legs half-heartedly across the gym floor in a kind of low, lunging motion, asks when they can stop.
The boys are not really reluctant, though, and clearly respect their tattooed and toned trainer, parkour expert Chris Grant. In an hour, he has all of them leaping and twisting through a metal rig in the corner, which looks like a small boxing ring constructed from solid bars.
They are among half-a-dozen or so teenage boys at Auchmuty High in Glenrothes who are learning parkour today as part of a project run jointly by the National Theatre of Scotland and regional arts body ON at Fife. Entitled "Jump", it is aimed at re-engaging boys who are disillusioned with school by harnessing their interest in the fascinating world of freerunning, as parkour is also known.
Encouraging troubled teenagers to "look cool" by flinging themselves off buildings sounds like lunacy, but that's not what the activity is about at all, as Glasgow-based Mr Grant explains.
"It has been really good to teach them that it's not like what they see on YouTube," he says. "They expect it to be an extreme sport with people jumping off roofs and doing backflips, being boisterous and showboaty, but it's not about that.
"Parkour is really just about overcoming obstacles . It's similar to martial arts - you learn how to solve problems and assess risk. It's a way of thinking more than a way of moving."
More than 1,000 second- and third-year boys in Fife and Glasgow have taken part in Jump sessions so far and Mr Grant says their focus and discipline has improved.
Organisers hope the boys will adopt the core values of parkour, including teamwork and discipline, as their philosophy of life to help them cope with the difficult transition of becoming men. To that end, they are being encouraged to share their views on what "being a man" means, with the results shaping a piece of physical theatre and parkour which 20 teenagers from each location will perform in November.
Robbie Mitchell, 13, says: "I would like to take part in the Fife show but I would not want a big part. "Parkour's all right, it's fun. It's taught us how to jump and land properly and not to take risks."
David Small, also 13, adds: "Whenever I'm at the beach I do free-running on the rocks; it's really fun. I've seen lots on YouTube and this (Jump) is a bit different to what I expected but it's brilliant."
Staff at the school say the boys' enthusiasm for the project has changed their attitude towards school.
Drama teacher Lauren Barr says: "They just went for it from day one. A few of the boys are on behavioural target sheets and this has been used as an incentive, with teachers warning - `Don't do that because next week the National Theatre of Scotland is coming.'
"I think Jump has improved their behaviour in a lot of areas at school."
It has also engaged boys who are not interested in drama and see it as "uncool", she says: "There have been comments like `I never knew this was drama'. It's giving them a better perspective of what drama is and widening their horizons.
"I would like to do this with my drama pupils. They see this and ask why they can't do it, too. It would expand their view of where they can go career-wise."
`PARKOUR IS A METAPHOR FOR LIFE. IT'S THE STEPS BETWEEN THE JUMPS THAT ARE IMPORTANT'
"Being born is your greatest achievement and you associate it with the theme from Titanic?" It is an unexpected response from a teenager at Auchmuty High in Glenrothes as a group of boys discuss music and what matters to them.
The scene is unusual, too, with Radio 1 DJ Ally McCrae among pupils, surrounded by a growing sea of Post-it notes. They are writing down their greatest achievement, favourite place, what frustrates them and what image they associate with the word "friends", plus a song or band to go with each answer.
McCrae and colleague David Weaver, who together form NME award-winning DJ and music events duo Detour Scotland, question their responses and debate which to pick.
The boys are taking part in a soundtrack workshop as part of Jump, a project using parkour to explore what being a man means and re-engage pupils in education.
Director Simon Sharkey, from the National Theatre of Scotland, says: "In every school we go to, they say it's difficult to find role models for boys and get them engaged.
"Parkour is a metaphor for life. It's the steps between the jumps that are important and have to be planned. When we talk about what it means to become a man and ask them what steps they need to get a job they say: `Oh, you need exams.'
"It's brilliant because they can `physicalise' it, which for boys is a great thing."
He says parkour is ideal because it's about strength - "and it is a bit macho (in image), so it gives boys a platform to express themselves without it being stigmatised.
The boys are also trying creative writing, penning raps with Glasgow artist MC Loki (pictured) and forming a BeatBox choir with Glasgow star, Bigg Taj.