Science
How do Olympic skateboarders catch serious airtime? Physicists crunched the numbers
Skateboarders call it “pumping,” and it’s a skill that both Olympic medalists and aspiring thrashers use to build launch speed from what seems like thin air.
But what separates the steeziest pro from the sketchiest beginner is the years’ worth of practice it takes to develop the know-how to execute the cleanest pump — or at least that was the case until now.
In a paper published Monday in the journal Physical Review Research, scientists have revealed the secret of achieving serious airtime.
A skateboarder rides the bowls at Etnies skatepark in Lake Forest. (Allen J. Schaben / Los Angeles Times)
With a bit of coding, researchers were able to describe the optimal technique for pumping — a tactic where skateboarders crouch down low momentarily and then push their body upright on inclines. To get the highest jump, they need to do it once as they descend into the bowl, and then again as they shoot back up toward the sky.
The trick is knowing when and where to execute the maneuver.
“Pumping is the foundation of skateboarding in skate parks,” said professional skater Haden McKenna, during a morning session at the Venice Beach Skatepark. “You build off of that and learn tricks. Then the pumping just becomes something in the back of your brain.”
However, the likeliest users of the researchers’ perfect pump equation are non-humans.
After skateboarding’s Olympic debut at the Tokyo Games, a research arm of the Japanese government reached out to Shigeru Shinomoto, a scientist at the Advanced Telecommunications Research Institute International in Japan. The organization had wondered if it was possible to build a skateboarding robot that could compete in the X Games.
The robot is still a ways off — right now it’s more like a toy that rides back and forth on a mini half-pipe — but the researchers discovered that the mechanics for good skateboarding technique can be surprisingly simple (well, at least compared to the complex fluid dynamics and neuroscience that they’re normally working on).
Kokona Hiraki of Japan crouches on her board before popping upright to pump at the Tokyo Olympics.
(Associated Press)
“It’s just this cute little project which became much bigger than we expected,” said Florian Kogelbauer, an author on the paper and a mechanical engineering professor at the public university ETH Zürich. “People like it — it’s a fun topic. It’s easy to explain, but some serious math and computational work went into it.”
To test their calculations, study authors recruited an expert skater with over a decade of experience, and a novice with just two years under their belt. They told the skaters to catch as much air as possible on a half-pipe erected in a research lab.
The result: The pro much more closely matched their calculated optimal motion than the amateur. (Ideally the skater would pop up instantaneously, but the researchers conceded that humans lack the unlimited muscle strength to do this — plus it would send the skater flying off their board.)
“The experiment seems to agree well,” said Frank Feng, a mechanical engineering professor at the University of Missouri who was not involved with the paper, but studied similar motions in half-pipe snowboarding.
Feng said the simple physics model gets researchers most of the way there, then the computer optimization is able to account for complexities that the physics equations can’t handle.
While the study was mostly just for fun, it snowballed into a fairly big project, and ended up getting published in one of the world’s premier physics journals. Part of the reason is that it may have some serious implications for how to get robots to move effectively without face-planting all the time.
It could help human skateboarders, too. Feng said the results could be used as a straightforward guide to help skateboarders train.
However, some question whether skaters would be able to use the information in the moment.
“This graph, showing the mass going up, is very helpful for somebody that can understand that,” said pro skater McKenna, who was not involved in the research. “But when you’re teaching kids and you’re trying to teach somebody that’s focused in the moment of skateboarding, they’re not going to be able to bring math into the equation.”
Also, out in the complex terrain of the park, the technique gets a bit more nuanced than a simple model the physicists developed. You need to flow as “one with the wall,” said McKenna. “Like what Bruce Lee says, ‘Be like water.’”
Skateboarder Greyson Godfrey, 20, of Rancho Santa Margarita drops into the bowl at Etnies Skate Park Lake Forest.
(Allen J. Schaben / Los Angeles Times)
While the researchers’ optimal solution may not always be the best suited for real-world conditions, it does help to illustrate the physics behind the technique.
Studio Gutierrez, who teaches skateboarding as a sports instructor to middle schoolers in the Los Angeles Unified School District, finds understanding the science helpful for new skaters. “I explain it to them in physics motions,” he said. “The more motion, the faster you go, the higher you get.”
The physics works similarly to how ice skaters increase the speed of their spinning in the Winter Olympics, said Kogelbauer. They start out spinning slow with their limbs extended outward. Then, they tuck their arms and legs in, causing them to spin faster.
Skateboarders also gain speed by using this technique on curved surfaces.
When a skateboarder hits the circular section of the half-pipe, they start crouched down, positioning their center of mass further from the center of rotation above their head. As they climb the curved ramp, they pop up and bring their center of mass closer to the center of rotation, and they speed up.
While the pumping paper is one of the first to capture the physics of pumping, its authors aren’t the only ones studying the motion of skateboarding.
Google has also taken a stab at a more complex understanding with its Project Skate. It’s using AI to identify different tricks and motions — but AI requires a lot of computing power that many researchers who aren’t Google don’t have access to.
“They have [essentially] unlimited resources. If they want to, they can take a new server farm and then run trajectories as much as they want.” said Kogelbauer. “That’s what Google does. We’re not Google.”
If you’d like to study pumping physics on your own, you can tune in to the Paris Olympics. The women skateboarders are scheduled to compete in the park event (as opposed to the street event, which has fewer curved surfaces for pumping) Tuesday morning. The men are scheduled for Wednesday.
McKenna has always seen skating more as an art form and community than a sport, but he’s stoked to watch nonetheless. “When I was a kid, which doesn’t seem that long ago, skateboarding was a crime, literally,” he said. “Now we’re winning gold medals in the Olympics.”
Science
Trump administration declares ‘war on sugar’ in overhaul of food guidelines
The Trump administration announced a major overhaul of American nutrition guidelines Wednesday, replacing the old, carbohydrate-heavy food pyramid with one that prioritizes protein, healthy fats and whole grains.
“Our government declares war on added sugar,” Health and Human Services Secretary Robert F. Kennedy Jr. said in a White House press conference announcing the changes. “We are ending the war on saturated fats.”
“If a foreign adversary sought to destroy the health of our children, to cripple our economy, to weaken our national security, there would be no better strategy than to addict us to ultra-processed foods,” Kennedy said.
Improving U.S. eating habits and the availability of nutritious foods is an issue with broad bipartisan support, and has been a long-standing goal of Kennedy’s Make America Healthy Again movement.
During the press conference, he acknowledged both the American Medical Association and the American Assn. of Pediatrics for partnering on the new guidelines — two organizations that earlier this week condemned the administration’s decision to slash the number of diseases that U.S. children are vaccinated against.
“The American Medical Association applauds the administration’s new Dietary Guidelines for spotlighting the highly processed foods, sugar-sweetened beverages, and excess sodium that fuel heart disease, diabetes, obesity, and other chronic illnesses,” AMA president Bobby Mukkamala said in a statement.
Science
Contributor: With high deductibles, even the insured are functionally uninsured
I recently saw a patient complaining of shortness of breath and a persistent cough. Worried he was developing pneumonia, I ordered a chest X-ray — a standard diagnostic tool. He refused. He hadn’t met his $3,000 deductible yet, and so his insurance would have required him to pay much or all of the cost for that scan. He assured me he would call if he got worse.
For him, the X-ray wasn’t a medical necessity, but it would have been a financial shock he couldn’t absorb. He chose to gamble on a cough, and five days later, he lost — ending up in the ICU with bilateral pneumonia. He survived, but the cost of his “savings” was a nearly fatal hospital stay and a bill that will quite likely bankrupt him. He is lucky he won’t be one of the 55,000 Americans to die from pneumonia each year.
As a physician associate in primary care, I serve as a frontline witness to this failure of the American approach to insurance. Medical professionals are taught that the barrier to health is biology: bacteria, viruses, genetics. But increasingly, the barrier is a policy framework that pressures insured Americans to gamble with their lives. High-deductible health plans seem affordable because their monthly premiums are lower than other plans’, but they create perverse incentives by discouraging patients from seeking and accepting diagnostics and treatments — sometimes turning minor, treatable issues into expensive, life-threatening emergencies. My patient’s gamble with his lungs is a microcosm of the much larger gamble we are taking with the American public.
The economic theory underpinning these high deductibles is known as “skin in the game.” The idea is that if patients are responsible for the first few thousand dollars of their care, they will become savvy consumers, shopping around for the best value and driving down healthcare costs.
But this logic collapses in the exam room. Healthcare is not a consumer good like a television or a used car. My patient was not in a position to “shop around” for a cheaper X-ray, nor was he qualified to determine if his cough was benign or deadly. The “skin in the game” theory assumes a level of medical literacy and market transparency that simply doesn’t exist in a moment of crisis. You can compare the specs of two SUVs; you cannot “shop around” for a life-saving diagnostic while gasping for air.
A 2025 poll from the Kaiser Family Foundation points to this reality, finding that up to 38% of insured American adults say they skipped or postponed necessary healthcare or medications in the past 12 months because of cost. In the same poll, 42% of those who skipped care admitted their health problem worsened as a result.
This self-inflicted public health crisis is set to deteriorate further. The Congressional Budget Office estimates roughly 15 million people will lose health coverage and become uninsured by 2034 because of Medicaid and Affordable Care Act marketplace cuts. That is without mentioning the millions more who will see their monthly premiums more than double if premium tax credits are allowed to expire. If that happens, not only will millions become uninsured but also millions more will downgrade to “bronze” plans with huge deductibles just to keep their premiums affordable. We are about to flood the system with “insured but functionally uninsured” patients.
I see the human cost of this “functional uninsurance” every week. These are patients who technically have coverage but are terrified to use it because their deductibles are so large they may exceed the individuals’ available cash or credit — or even their net worth. This creates a dangerous paradox: Americans are paying hundreds of dollars a month for a card in their wallet they cannot afford to use. They skip the annual physical, ignore the suspicious mole and ration their insulin — all while technically insured. By the time they arrive at my clinic, their disease has often progressed to a catastrophic event, from what could have been a cheap fix.
Federal spending on healthcare should not be considered charity; it is an investment in our collective future. We cannot expect our children to reach their full potential or our workforce to remain productive if basic healthcare needs are treated as a luxury. Inaction by Congress and the current administration to solve this crisis is legislative malpractice.
In medicine, we are trained to treat the underlying disease, not just the symptoms. The skipped visits and ignored prescriptions are merely symptoms; the disease is a policy framework that views healthcare as a commodity rather than a fundamental necessity. If we allow these cuts to proceed, we are ensuring that the American workforce becomes sicker, our hospitals more overwhelmed and our economy less resilient. We are walking willingly into a public health crisis that is entirely preventable.
Joseph Pollino is a primary care physician associate in Nevada.
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Ideas expressed in the piece
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High-deductible health plans create a barrier to necessary medical care, with patients avoiding diagnostics and treatments due to out-of-pocket cost concerns[1]. Research shows that 38% of insured American adults skipped or postponed necessary healthcare or medications in the past 12 months because of cost, with 42% reporting their health worsened as a result[1].
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The economic theory of “skin in the game”—which assumes patients will shop around for better healthcare values if they have financial responsibility—fails in medical practice because patients lack the medical literacy to make informed decisions in moments of crisis and cannot realistically compare pricing for emergency or diagnostic services[1].
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Rising deductibles are pushing enrollees toward bronze plans with deductibles averaging $7,476 in 2026, up from the average silver plan deductible of $5,304[1][4]. In California’s Covered California program, bronze plan enrollment has surged to more than one-third of new enrollees in 2026, compared to typically one in five[1].
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Expiring federal premium tax credits will more than double out-of-pocket premiums for ACA marketplace enrollees in 2026, creating an expected 75% increase in average out-of-pocket premium payments[5]. This will force millions to either drop coverage or downgrade to bronze plans with massive deductibles, creating a population of “insured but functionally uninsured” people[1].
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High-deductible plans pose particular dangers for patients with chronic conditions, with studies showing adults with diabetes involuntarily switched to high-deductible plans face 11% higher risk of hospitalization for heart attacks, 15% higher risk for strokes, and more than double the likelihood of blindness or end-stage kidney disease[4].
Different views on the topic
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Expanding access to health savings accounts paired with bronze and catastrophic plans offers tax advantages that allow higher-income individuals to set aside tax-deductible contributions for qualified medical expenses, potentially offsetting higher out-of-pocket costs through strategic planning[3].
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Employers and insurers emphasize that offering multiple plan options with varying deductibles and premiums enables employees to select plans matching their individual needs and healthcare usage patterns, allowing those who rarely use healthcare to save money through lower premiums[2]. Large employers increasingly offer three or more medical plan choices, with the expectation that employees choosing the right plan can unlock savings[2].
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The expansion of catastrophic plans with streamlined enrollment processes and automatic display on HealthCare.gov is intended to make affordable coverage more accessible for certain income groups, particularly those above 400% of federal poverty level who lose subsidies[3].
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Rising healthcare costs, including specialty drugs and new high-cost cell and gene therapies, are significant drivers requiring premium increases regardless of plan design[5]. Some insurers are managing affordability by discontinuing costly coverage—such as GLP-1 weight-loss medications—to reduce premium rate increases for broader plan members[5].
Science
Trump administration slashes number of diseases U.S. children will be regularly vaccinated against
The U.S. Department of Health and Human Services announced sweeping changes to the pediatric vaccine schedule on Monday, sharply cutting the number of diseases U.S. children will be regularly immunized against.
Under the new guidelines, the U.S. still recommends that all children be vaccinated against measles, mumps, rubella, polio, pertussis, tetanus, diphtheria, Haemophilus influenzae type B (Hib), pneumococcal disease, human papillomavirus (HPV) and varicella, better known as chickenpox.
Vaccines for all other diseases will now fall into one of two categories: recommended only for specific high-risk groups, or available through “shared clinical decision-making” — the administration’s preferred term for “optional.”
These include immunizations for hepatitis A and B, rotavirus, respiratory syncytial virus (RSV), bacterial meningitis, influenza and COVID-19. All these shots were previously recommended for all children.
Insurance companies will still be required to fully cover all childhood vaccines on the CDC schedule, including those now designated as optional, according to the Department of Health and Human Services.
Health Secretary Robert F. Kennedy Jr., a longtime vaccine critic, said in a statement that the new schedule “protects children, respects families, and rebuilds trust in public health.”
But pediatricians and public health officials widely condemned the shift, saying that it would lead to more uncertainty for patients and a resurgence of diseases that had been under control.
“The decision to weaken the childhood immunization schedule is misguided and dangerous,” said Dr. René Bravo, a pediatrician and president of the California Medical Assn. “Today’s decision undermines decades of evidence-based public health policy and sends a deeply confusing message to families at a time when vaccine confidence is already under strain.”
The American Academy of Pediatrics condemned the changes as “dangerous and unnecessary,” and said that it will continue to publish its own schedule of recommended immunizations. In September, California, Oregon, Washington and Hawaii announced that those four states would follow an independent immunization schedule based on recommendations from the AAP and other medical groups.
The federal changes have been anticipated since December, when President Trump signed a presidential memorandum directing the health department to update the pediatric vaccine schedule “to align with such scientific evidence and best practices from peer, developed countries.”
The new U.S. vaccination guidelines are much closer to those of Denmark, which routinely vaccinates its children against only 10 diseases.
As doctors and public health experts have pointed out, Denmark also has a robust system of government-funded universal healthcare, a smaller and more homogenous population, and a different disease burden.
“The vaccines that are recommended in any particular country reflect the diseases that are prevalent in that country,” said Dr. Kelly Gebo, dean of the Milken Institute School of Public Health at George Washington University. “Just because one country has a vaccine schedule that is perfectly reasonable for that country, it may not be at all reasonable” elsewhere.
Almost every pregnant woman in Denmark is screened for hepatitis B, for example. In the U.S., less than 85% of pregnant women are screened for the disease.
Instead, the U.S. has relied on universal vaccination to protect children whose mothers don’t receive adequate care during pregnancy. Hepatitis B has been nearly eliminated in the U.S. since the vaccine was introduced in 1991. Last month, a panel of Kennedy appointees voted to drop the CDC’s decades-old recommendation that all newborns be vaccinated against the disease at birth.
“Viruses and bacteria that were under control are being set free on our most vulnerable,” said Dr. James Alwine, a virologist and member of the nonprofit advocacy group Defend Public Health. “It may take one or two years for the tragic consequences to become clear, but this is like asking farmers in North Dakota to grow pineapples. It won’t work and can’t end well.”
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