It’s the woozy internet video clip which launched a craze, and in turn, a sport. “You have to see it to believe it!” says the intro, before fading into blurred footage of Emily Fox, 14, setting the world record at arranging upturned plastic cups into pyramids, or, as it’s now called, Sport Stacking. After watching the jawdropping spectacle of cups almost flowing from her hands, you might cynically dismiss Emily’s feat as the pointless achievement of a girl with a little too much spare time. But with encouragement from teachers in thousands of American schools, children are becoming obsessed with stacking these brightly coloured plastic beakers, and, while their Playstations slowly gather dust under the bed, the word is starting to spread over here.

At Frith Manor Primary School in North London, teacher Alison Reese has set up a Sport Stacking club for 30 children, and there’s 40 more waiting impatiently for the chance to join. Ron Parker from Speed Stacks, the company who promote the sport and sell cup stacking paraphernalia, has come to the school to help demonstrate the sport in morning assembly, and to present the club with a digital display which will help measure stacking speeds to within 1/100 of a second. The club members bound into the hall, each of them clutching a string bag containing 12 plastic cups, thrilled that their hobby is being taken seriously enough to demote the headmaster, Mr Herring, to the status of spectator. The demonstration begins: sets of cups are stacked and destacked in relays, with the wide-eyed members of each tag-team rushing forward and employing the approved stacking method (grip lightly and let gravity do the work) to assemble pyramids of 3, 6 or 10. Nervous fingers knock a cup or two off the table and into the laps of the transfixed, cross-legged audience, who are soon beset with an urge to cheer on the action at a deafening volume. Even the teachers, for whom assembly is often a time for some gentle daydreaming, join in the encouragement. Emmeline Kos, the club’s fastest stacker, records a time of 14.77 seconds for a full cycle of cup stacking; Alison Reese has high hopes for her, and would dearly love to take her to the World Championships in April. “She was the one who had the idea for the club. She claims that she’s done a cycle in 10 seconds, but I’ve not been able to officially verify this,” she laughs. The pressure of having a big audience proves to be too much for Emmeline, and she looks crushingly disappointed as one of her stacks tumbles over during another attempt to beat her official best of 11.70 seconds. But the headmaster rounds off the assembly with words of encouragement. “Cup stacking is good for all of us, and hopefully we’ll see even more of you doing it before long.”

While children continue stacking cups during the morning break, Ron Parker – who is wearing a tracksuit emblazoned with the words “Stack Fast” – looks on, approvingly. His introduction to Sport Stacking was in 2001 when he saw Emily Fox in action on television. After buying a set of cups from the USA he struck up a correspondence with Bob Fox, who is the founder of Speed Stacks and – perhaps unsurprisingly – Emily’s father. Parker’s daughter, Kate, quickly became proficient, laid claim to the title of UK record holder, and secured a family visit to the World Championships in Colorado. During the event Ron was offered the chance of promoting the sport in the UK, at which point he quit his job of 21 years as a British Telecom engineer and has been evangelising ever since. “I love converting sceptics,” he explains. Charmian Boyes, inclusion co-ordinator at Frith Manor, didn’t require much persuasion. “I saw a stacking demonstration at an exhibition and immediately saw that it was fun, inclusive, wonderful for children with concentration problems and tremendous for PE lessons.” She introduced the sport to the school at an inset training day for 50 teachers, who all sat on the floor of the gym, stacking furiously. Alison Reese: “Everyone else went to lunch, but I was still there, desperately trying to complete a full cycle. I was hooked immediately.” Reese is far from unique. The Speed Stacks website contains numerous testimonials from teachers, detailing the ways the sport benefits hand-eye co-ordination, concentration, ambidexterity and team skills, which in turn assist with proficiency in other sports at a time when interest in PE is at a particularly low ebb. Emily Fox herself is a good example; having started playing basketball at the same time she started stacking, she recently won a basketball scholarship to Wisconsin University and, now at the age of 17, is seen as one of the USA’s great hopes for the future. Her father is certain that the hours she spent stacking have been instrumental in her success.

So it’s good for children, and popular with children, and as the kids build their “Positive Pyramids”, Speed Stacks is naturally reaping the financial rewards. There are no barriers to other companies producing stacking equipment, but by getting in there first, and indeed founding the World Sport Stacking Association (WSSA) as a regulatory body, Bob Fox has come up with a business idea which approaches a monopoly. With normal plastic cups prone to sticking together and severely hampering ones stacking potential, Speed Stacks provide the answer by selling the authorised cups in a variety of hues, along with rubber stacking mats (the noise can be deafening without them), timing devices, deluxe chrome-finished sets and sweatshirts bearing the legend “United We Stack”. Ron Parker acknowledges that it’s a business he’s helping to run, but stresses the care with which they operate. “All our marketing is done through schools – not through toy stores – and all the cups are warrantied, with free replacements. We also give away a lot of equipment, run free workshops in schools and hospitals, and never pressurize on sales.”

As well as stressing the educational value of stacking, Speed Stacks and the WSSA continue to pursue recognition of stacking as a bona fide sport. Up until the end of last year, Sport Stacking was known as Cup Stacking, and, similarly, the WSSA was once the WCSA. A delicate semantic shift, which is supposed to give an “immediate identification of cup stacking as a competitive sport.” Anticipating any critics who might think that cups are inferior pieces of sporting equipment compared to tennis balls and hockey sticks, the WSSA website contains a mission statement, a rule book and an emphasis on their commitment to “the standardization and advancement of cup stacking”. With fads like hula-hoops and hacky sacks having arrived and disappeared without trace, it’s a slightly absurd but perhaps unsurprising attempt to boost the sport’s credibility. Children, of course, require their hobbies to have a different kind of cred, and Speed Stacks have thought of that, too: a promotional DVD with spinning graphics and a clattering hip-hop soundtrack shows attractive teens stacking cups on tables in front of a display of skateboarding, while an excitable commentary urges us to attempt a session of Cup Jammin’; this turns out to be stacking cups while balanced precariously on a miniature see-saw.

But the children at Frith Manor are too fanatical about their competitions to worry about any notions of cool. At the end of morning break they reluctantly pack up their cups and go back into lessons – but even in a nearby classroom, they are still stacking away like children possessed. They’re besotted with these bits of plastic. When I get home I finger my souvenir stack-pack nervously. “Would YOU like to be bilaterally proficient?” asks the Speed Stacks blurb. I would. But I’m almost too scared to get the cups out.