To call cup stacking popular is a major understatement.
"I could not believe the impact it had on students," said physical education teacher John Dunlop. "Seriously, I was floored."
"It changed my life," said student Jason Counts. "Before then, I was kind of going down the wrong path. Since I got into cup stacking, I've changed tremendously."
In more than 7,500 programs around the world, students from elementary grades through college are stacking and unstacking 12 plastic cups, faster and faster. It's an individual or team sport in which they place cups in multiple stacks and sequences (such as "three-six-three" or "one-10-one") and compete against the clock or each other.
Teachers like it because kids of all ages and abilities compete equally. Students like it because they quickly see improvement with practice.
But is it really physical education? Can it be called a sport? And does it, as proponents claim, improve brain function?
One thing is certain: Kids are bonkers for it.
"It's not often kids go home and rave about what they're doing in phys ed," said Dunlop, a gym teacher at Portage Central Middle School in Portage, Mich. "Parents come up to me in the grocery store and ask where to get stacking cups for their kids."
At Lake Center Elementary School in Portage, where Dunlop also started a program, 285 students out of 450 now have their own stacking cups.
All this cupmania is courtesy of Bob Fox of Highlands Ranch, Colo., a former physical educator who left after 17 years to devote himself to the activity.
Fox was intrigued when he first saw cup stacking on the "Tonight Show" around 1990. The history of the sport before then is hazy, he said. In 1995, Fox introduced it to his students.
"The kids went nuts over it," Fox said.
That enthusiasm spread to other schools, and soon Fox was introducing stacking throughout Colorado. In 2000, he left teaching to start his own company, Speed Stacks, in Englewood, Colo., which sells special cups (with holes to allow faster movement) and timing equipment.
Fox also launched the World Cup Stacking Association to "promote the standardization and advancement of the sport of cup stacking worldwide." At the 2005 world championships, he expects some 1,000 competitors.
Stacking has caught on not only in schools but in summer camps, church youth groups and special education classes, Fox said. Therapists use it with stroke victims to regain strength and coordination. Athletic trainers, amateur and professional, encourage clients to stack.
In just four years, Speed Stacks distributors have spread to Australia, Scandinavia, the United Kingdom, Japan and Singapore. "We have a real world vision," Fox said. "We see it as a very universal sport."
Emily Fox, his daughter, won the three-six-three stack competition in May at the 2004 world championships in Denver, with a time of 3.02 seconds. She began stacking when she was 9; now she's a senior in high school. Next year she'll be at the University of Minnesota on a full-ride basketball scholarship. (Videos of Emily stacking are at www.speedstacks.com.)
"She's a point guard, and has very, very fast hands," Fox said. "She's equally fast on both sides of her body. We really believe that's in large part due to cup stacking."
One study shows that may be true. Brian Udermann, an exercise and sports science professor at University of Wisconsin LaCrosse, devised a study comparing a second-grade class that stacked with one that didn't.
"To see the amount of improvement we saw surprised me," Udermann said.
The cup stacking "significantly improved" eye-hand coordination and reaction time among cup stackers, "in the magnitude of 25 percent to 30 percent," Udermann said. His findings were published this year in the Journal of Perceptual and Motor Skills.
Fox touts stacking for building "bilateral proficiency," or equal performance on both sides of the body. By practicing stacking, he contends, participants develop a greater percentage of their right brain, which controls abilities including focus, creativity and rhythm.
Neurobiologist Lawrence Katz is dubious. He's a professor at Duke University Medical Center and author of "Keep Your Brain Alive: 83 Neurobic Exercises."
"Is cup stacking better than playing a Game Boy?" Katz said. It, too, is "fast, ambidextrous and strategic."
Some physical educators are also cautious. Dolly Lambdin, president of the National Association for Sport and Physical Education, said cup stacking "is only one of a couple hundred activities teachers do with kids, and probably not one with the most health benefits."
Lambdin said she would prefer to see more focus on "guiding kids to become physically active for the rest of their lives," to combat the growing problem of obesity.
Jason Counts began stacking in elementary school. Now 15 and a freshman at Forest High School in Ocala, Fla., he came in first in the cycle stack at the 2004 world championships, at 8.24 seconds.
He sees stacking as a sport, and considers himself an athlete. "I go into competition to win," he said. Counts has an area at home for his cups and StackMat Competition Timer, a device that records when the stacker starts and stops.
"When I first started, I practiced four or five hours a day – it drove my mom nuts," Counts said. "As I got better, I got it down to two hours. Now I practice 20 to 30 minutes every other day."
Counts said that before stacking, his grades were poor and he was "not doing too well at home." Stacking gives him something to concentrate on, he said.