Science Friday - Jump, Spin, Glide: The Science Of Figure Skating

Episode Date: February 18, 2026

Figure skating is a fan favorite at the Winter Olympics—for every event, the stands are packed to watch competitors glide, jump, and spin. But what does it take to pull off these seemingly effortless moves? Figure skating researcher Deborah King joins Host Ira Flatow to unfold the science of the sport, from the impressive jumps of US skater Ilia Malinin, to the g-forces endured by the ankles of a speeding skater.Guest: Dr. Deborah King is a professor of exercise science and athletic training at Ithaca College in Ithaca, New York.Transcripts for each episode are available within 1-3 days at sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Hi, it's Ira Flato, and you're listening to Science Friday. Today on the podcast, we're in training for the final events in figure skating at the Olympics. When I watch the athlete spin and jump and glide while balancing on a razor-thin skate blade, I wonder how some of these seem to defy the laws of physics. And they test the limits of what the human body can do, don't they? Especially the quadruple axle and the backflip performed by Ilya, Well, here to guide us through the biomechanics of the fantastic feats on ice is Dr. Debra King. She's a professor of exercise science and athletic training at Ithaca College in Ithaca, New York.

Welcome back to Science Friday. Thank you, Ira. Happy to be here. Nice to have you. Let me just ask, do you skate yourself? I am not a figure skater. No. I grew up just skating around like outdoor rinks or ponds, but it was never a sport I participated in.

Me neither. I did a couple of times on ice, but I don't even want to talk about what the results were. So to non-skaters, I mean, don't they make all these difficult jumps seem so effortless? I have a difficult time telling the hard elements from the easy elements. So that's why you're here. What's the hardest skill for a figure skater to do physically? Today, in men's figure skating specifically, the hardest technical skill that's being done is the quadruple axle, which is only being done in competition by Ilya Malinen. Describe what that is. Okay, so the quadruple axle is a jump that is unique in that as an axle jump, the skaters steps forward and is facing forward when they jump into the air. and people might not have noticed this when they're watching the Olympics, but if you pay a little

attention to the landings, you'll notice they're always landing their jumps backwards. So that means if you're jumping off forward and doing a quadruple jump, there's actually an extra half revolution you have to complete so that you're facing backwards. So it's a four and a half revolution jump compared to the other quadruple jumps, which in and of themselves are very difficult, but require four revolutions because they take off backwards. You do four revolutions and land backwards. Now, I would think you have to be up in the air long enough and you have to be able to spin fast enough. You're absolutely right. In the quadruple axle, you're probably seeing air times 0.8.9 seconds. They're usually in the air only about just a little under a second. When you watch the

jump, it looks like it takes a little longer because you're watching the approach and you watch the glide out of the landing. But just the airtime itself is just under a second. But if you're doing four and a half revolutions in a second, that is spinning amazingly fast. I know if my head were spinning that quickly, I couldn't balance myself or know where the heck I was. Right. But you have to be able to do that, right? Right.

Like your body awareness in the air so you know what revolution you're at. And I don't know if anybody of your listeners have notices while they're watching skating that you don't see skaters like spot. Like if you were watching ballet or something and doing turns that head spots while they're doing rotations. But if you're doing four and a half revolutions in a second, you're not going to be able to spot and turn your head. So having your body awareness to be able to know where you are in the air and land is obviously amazingly difficult. Wow. So why is it that he's able to do this? Does he have a special talent or is it practice or what? I think it's going to be sort of all of the above. One thing if you watch him jump that I think is amazingly impressive about his jumps is how high he goes.

So he gets off the ground really quickly, has a lot of power and just goes really high. But while he's doing that, if you watch his body position, it seems like he has almost immediately gotten into a really straight, tight body position. So his legs are straight underneath them. They're pressed really tight together. His arms come in really tightly across his chest. So he's going high, but snapping into his rotating position so quickly. Right. So there's not like a moment wasted while in the air.

where he's not able to rotate really fast. One of the problems he said he had during his failed attempts was that his head wasn't on straight, so to speak. I guess the mental side of this is major. Oh, absolutely. The pressure to perform, and he's been world champion and winning so many competitions and programs over the last almost four years. And the Olympics only come around once every four years.

So that's a pretty heavy expectation that everyone has for you. But those are really difficult skills to do. And no one's going to land them perfectly all the time. And unfortunately, you've got to put the physical performance together and the mental performance together all at the right moment. Yeah. So I guess all the elements vary from one skater to another. I mean, does body size matter?

Oh, body size is a hugely important factor in figure skating jumps. There's a quantity in physics that we call the moment of inertia. and it really is a measure of an object's resistance to angular acceleration. So when he goes in the air, he wants to have a little resistance to angular acceleration so he can rotate really fast. And objects that can rotate really fast with small moments of inertia are really narrow. So you don't want your body parts sticking out. You don't want wide shoulders.

You don't want wide hips. So people who can be really long and narrow, almost like a pencil in the air, have an actual smaller moment of inertia. and that will allow them to rotate faster than someone who doesn't have a small moment of inertia. So that's one way body shape can make a difference. So that's like why you spin faster when you pull your arms in? Absolutely. Anybody who's ever gone to the playground and played on the tire swing or on the merry-go-round

and you can make it go faster by pulling your arms in, that's the concept right there. But you also might notice when you try to pull your arms and legs in on the tire swing, it feels like they want to pull away from you. Right. So you have to be really strong to hold them in so that you can keep rotating fast and you don't slow down in the middle of the jump. So how much of a performance is dictated by the physics? You mentioned this a bit. If you position your arm or your leg in a specific way at a specific time, if you don't do that, you're going to affect your performance because of the physics involved.

Absolutely correct. So I think every skater is constrained by the laws of physics and needs. to utilize their technique to be sure that they can optimize their performance within the laws of physics. Not that they cognitively need to think about the laws of physics while they're jumping, but the techniques that they use will allow them to work within those constraints of the time that you have in the air and your rotation speed need to be balanced out so you don't under or over-rotate the jump, for example, if we're just talking about completing four and a half revolutions. Well, let's talk about the laws of physics and the back.

backwards flip that was just mind-boggling. Is it a really hard thing to do or just something that your average good skater can do? That's a really good question. If you think about it from a physics standpoint, you need to get enough, I guess, I would call it flip momentum, that you can get all the way over so that you get your feet back underneath you because you don't want to come up short. Because if you come up short, right, you're going to land sort of on your knees or your face, which would not be good. And you don't want too much flip momentum that you sort of overrotate and then end up falling on your back. Yeah.

Yeah, I hate it when that happens. I'm sure the skaters do, too. One thing that always stuns me is how they can go from spinning really fast to standing still or from a spin to moving in a straight line. I mean, how do they shed all that momentum without seeming to slow down? I think there's two different concepts that are being used to slow down their momentum. So one is that moment of inertia that we talked about. Generally, they're spinning really fast and then all of a sudden you see them open their arms up. So they're extended out from their body.

And so that's going to slow you down a lot. And the other thing that is probably harder to visualize when you're watching them would be any torque being created from their skate against the ice. So skaters use the way they glide into a jump and the way they move their body on their blade to generate torque as they're skating. When you see skaters skate, they skate on curve. So they're coming in on a curve as they go into a jump. They come in on a curve as they go out of a jump. So they have angular momentum as they come in and they still have some angular momentum as they come out. So it's hard to see that they're generating anger momentum.

The same would be true in a spin, which you were talking about, that they come in. and they're on a curve so that's generating angular momentum, and then they just snap their arms and legs in, they go really fast. And then they can open up and they'll slow down, but they can also, when they stop, like put the toe pick up their other foot in the ice, for example, and that will help create a force that will stop their angular momentum. Right. Well, speaking of forces, is it possible to measure the forces that are on the skaters' feet in their ankles

and compare it to something non-skaters might understand? Yes, sort of. of, we don't have a lot of really good equipment that naturally goes with a figure skate to measure the forces on the ice. There are a bunch of researchers working on it, but we have some really good estimates. Some of the probably better estimates that either I've tried to look at or other people have looked at are for jumps that are probably as high as Ilius quad axle are. He could be having forces up eight to ten times his body weight when he comes down. A lot depends. on your landing style or technique, you can land very stiffly and have a higher force or land

absorbing force through your ankle and hip and have a slightly lower force. So we probably need to give a range because it hasn't necessarily been measured directly for him. So eight to ten times your body weight, gosh. Eight to ten G's? Exactly. Yeah. That high force is only for several milliseconds. So it's not like a fighter pilot or race car driver going around a corner for a long period of time. That would be pretty much hard to withstand by the human body. But you're talking like 100th or 200th of second, you get this big impulse shockwave up your leg that's going to be close to a jump that high, eight to 10. Wow, without breaking any bones or pulling any muscles. Ideally, yes. I'm trying to compare it to a ballet, a ballerina or somebody who's on their toes like

that. I guess they're not jumping quite that high and coming down that fast. Well, I, I think, think a ballet dancer probably jumps that high. I think I don't 100% know, but I would think they could come close to that height. I think a difference in a ballet dancer in the landing versus a figure skate is for at least most ballet that I've watched when they land, they land on the ball of their foot and they go through a bigger range of motion so they lower themselves through the ankle, knee and hip more gradually towards the ground. So it's less abrupt. So it won't take quite as much force to act on the body during the landing to stop the person's downward momentum. You could think of it a lot like a safer barrier in NASCAR or the shock absorption in a football

helmet that if you have something that can absorb forces and deform when you land, in this case like a ballet dancer's ankle knee and hip can go through a range of motion and spread the impact over a longer time period so the forces can be lower. And skating, that's a little more challenging you need to do, but you do see skaters who have more of a neat deep end and more of a hip flexion when they land. And sometimes they come down a little more stiff. So that's why maybe some of them you might see. It's probably closer at six times body weight. And sometimes they come down really stiff and it might be closer at 10 times body weight. Do you think some of the skaters might perform well in the other acrobatic events, are the half pipe, snowboard, freestyle skiing?

Oh, that's a great question. So I think what is unique to skating is that they mostly do twisting, except for, like you said, the backflip that we saw from Ilya. Another sport that does a lot of twisting in the Winter Olympics is aerials. But when you see the half-fight, they're doing a lot of twisting, but they're also doing a lot of flipping and inverts at the same time. So I think it might depend on the sport, which one, it would be easier for them to transfer their rotational skills to, I would think aerial skiing, even though you would now have long skis.

At least the twisting, they are inverted. in aerial skating because they come off the ramp and they are flipping while they're going, but the motion they pick up is really a twist motion, which is much more like skating. Yeah, you know, there are a lot of skating events at the Olympics. How different is this skating from a different kind of skating, like speed skating or other kinds of skating? Is it a whole different thing? I'm going to go into a whole different thing. Not that a skater who figure skates does, they know how to skate.

So could they put on a pair of speed skates and go around probably? But even the equipment is very different, particularly if you look, what you've looked at all of them in short track, speed skating. The boot comes up over the ankle, but the blades, if you look down from the top, the blades are offset from the middle so that they can lean going around the corners. And if you look at a speed skate that's for the long track, when you look at their boots, the boots usually are not coming up over the ankle, and they have a hinge on the front. So when you push off, you can have a more smooth transition of force all the way through the stroke.

So I think people could probably put them on and skate not immediately fall over like I might, but they not just going to be able to transfer their skills from one to the other. I get it. The free program, that's only about, well, only, it's only about four minutes long. pretty long for me if I was skating. Right. But there's so much athleticism packed in. So I'm saying and thinking that endurance, cardio must be a very big component here. Yeah. The free skate, so you're absolutely right four minutes. That's an extremely difficult length of time to train for. That's like a miler in track and field. So it's a combination of both

aerobic power. We're using oxygen and then your anaerobic energy systems. And so that's a particularly difficult time to train for because it's not predominantly aerobic and it's not predominantly anaerobic. So it involves you training both systems. And you need to obviously get through the four minutes, but you need to get through the four minutes while you're doing jumps, but then transitioning to gliding beautifully across the ice and then doing something with a very immediate need for power, like another jump and balancing on one leg. So it's, challenging your energy systems, while you also have to present yourself, like, beautifully, doing really difficult skills that are fast, but also skills that are slow and under the control

of your body, if that makes sense. It does make sense. My last question for you, and it's a question about questions. I mean, what are the big questions in figure skating physics? What are a sports scientist interested in learning? So I think one thing is really quantifying the loads with landing and seeing how the loads are related to the difficulty of the skill, for example. Are the loads that we're seeing from different skaters, do they relate to overuse injuries that we see in skaters so that we could have some really evidence-based advice on training and scheduling training to try to reduce injuries? And another one would be thinking about off-ice training and how to do you.

targeting different muscle groups and different abilities and aspects of skater and off-ice training, is that really translating into techniques on ice that are either one helping with their performance and or helping to reduce injuries. Do you have an Olympic weakness? I mean, a sport that you have to watch? I have more than one Olympic weakness. Cross-country skiing absolutely have to watch. And the downhill.

I'm more of a curling guy. Oh my gosh, I love curling too. It's been great to have you back on the show. Well, thank you so much. It's been a pleasure. Deborah King, Professor of Exercise Science and Athletic Training at Ithaca College, of course, in Ithaca, New York. This episode was produced by Charles Burkwest. And honestly, we'd love you to rank our elements high for both. technical merit and artistic impression.

Rate and review us wherever you get your podcasts. I'm Ira Flato. We'll see you soon.