Skateboarders call it “pumping,” and it’s a skill used by Olympic medalists and aspiring thrashers alike to build up high speeds from nothing.
But what separates the most dour professional from the sketchiest novice is the years of practice it takes to develop the know-how to execute the cleanest pump—or at least that’s been the case until now.
In a paper published Monday in the journal Physical Review Research, scientists have revealed the secret to getting serious airtime.
With a little coding, researchers were able to describe the optimal technique for pumping — a tactic in which skateboarders crouch down briefly and then push their bodies upright on ramps. To get the highest jump, they have to do it once as they descend into the bowl, then again as they shoot back up toward the sky.
The trick is knowing when and where to perform the maneuver.
Read more: Have you ever seen a star explode? You’ll soon have the chance
“Pumping is the foundation of skateboarding at skateparks,” pro skater Haden McKenna said during a morning session at Venice Beach Skatepark. “You build on that and learn tricks. Then pumping just becomes something in the back of your brain.”
The most likely users of the researchers’ perfect pump equation, however, are non-humans.
After skateboarding made its Olympic debut at the Tokyo Games, a Japanese government research unit contacted Shigeru Shinomoto, a scientist at Japan’s Advanced Telecommunications Research Institute International. The organization wondered if it was possible to build a skateboarding robot that could compete in the X Games.
The robot is still a long way off – right now it looks more like a toy riding back and forth on a mini halfpipe – but the researchers found that the mechanics of good skateboarding technique can be surprisingly simple (well, at least compared to the complex fluid dynamics And neuroscience what they normally work on).
“It’s just a cute little project that has become much bigger than we expected,” said Florian Kogelbauer, an author of the paper and a professor of mechanical engineering at the public university ETH Zurich. “People like it — it’s a fun topic. It’s easy to explain, but there’s some serious mathematical and computational work that went into it.”
To test their calculations, the study authors recruited an experienced skater with more than a decade of experience and a novice with only two years of experience. They told the skaters to catch as much air as possible on a halfpipe set up in a research lab.
The result: The pros came much closer to their calculated optimal motion than the amateurs. (Ideally, the skater would immediately jump up, but the researchers acknowledged that humans don’t have the unlimited muscle power to do this — plus, the skater would fly off his board.)
“The experiment seems to be pretty accurate,” said Frank Feng, a professor of mechanical engineering at the University of Missouri who was not involved in the paper but has studied similar movements in halfpipe snowboarding.
Read more: For these Death Valley residents, extreme heat is a way of life
According to Feng, researchers can go a long way with a simple physics model, but computer optimization can then take into account complexities that the physics equations cannot handle.
While the study was mostly for fun, it grew into a fairly large project and was eventually published in one of the world’s top physics journals. Part of the reason is that it could have serious implications for how robots can move effectively without lying with your face on the ground all the time.
It could also help human skateboarders. Feng said the results could be used as a simple guide to help skateboarders train.
However, some question whether skaters can use the information at that time.
“This graph, showing the mass going up, is very useful for someone who can understand that,” said pro skater McKenna, who was not involved in the study. “But if you’re teaching kids and you’re trying to teach someone who’s focused on the moment of skateboarding, they’re not going to be able to put the math into the equation.”
Even in the park’s complex terrain, the engineering becomes more nuanced than a simple model developed by physicists. You have to be “one with the wall,” McKenna said. “As Bruce Lee says, ‘Be like water.'”
While the researchers’ optimal solution may not always be the most appropriate for real-world conditions, it does help illustrate the physics behind the technique.
Studio Gutierrez, who teaches skateboarding as a sports instructor to high school students in the Los Angeles Unified School District, finds understanding the science helpful for new skaters. “I teach them in physics of movement,” he said. “The more movement, the faster you go, the higher you go.”
The physics work similarly to how speed skaters increase the speed of their spinning during the Winter Olympics, Kogelbauer said. They start by spinning slowly with their limbs extended outward. Then they pull their arms and legs in, which speeds up the spinning.
Skateboarders also gain speed by using this technique on curved surfaces.
When a skateboarder hits the circular portion of the halfpipe, he begins to squat, which moves his center of mass farther away from the center of rotation above his head. As he climbs the curved ramp, he jumps upward, bringing his center of mass closer to the center of rotation, and accelerates.
Read more: One of the oldest known plants on Earth is at the center of the battle over development in California
Although the pumping article is one of the first to document the physics of pumping, the authors are not the only ones studying the motion of skateboarding.
Google has also taken a stab at more complex understanding with Project Skate. It uses AI to identify different tricks and moves, but AI requires a lot of processing power that many non-Google researchers don’t have access to.
“They have [essentially] unlimited resources. If they want, they can take a new server farm and then run trajectories as much as they want,” Kogelbauer said. “That’s what Google does. We’re not Google.”
If you want to study the physics of pumping for yourself, you can sign up for the Paris Olympics. The female skateboarders are scheduled to compete in the park event on Tuesday morning (as opposed to the street event, which has fewer curved surfaces for pumping). The men are scheduled for Wednesday.
McKenna has always viewed skating as more of an art form and a community than a sport, but he still enjoys it. “When I was a kid, and it doesn’t seem that long ago, skateboarding was literally a crime,” he said. “Now we’re winning gold medals at the Olympics.”
This story originally appeared in the Los Angeles Times.