Click on NOTE CATEGORIES to browse by topic, read through the entire archives, or type a topic in the search box.
OVERVIEW
(time codes are approximate)
00:08:45 - Are Humans Swimmers? (Jump to section)
00:20:40 - Swimming, Body Parts, and Adaptation (Jump to section)
00:34:45 - Strokes and Nutrients (Jump to section)
00:40:50 - Charting Your Swimming Micro Nutrients (Jump to section)
00:47:00 - Swimming and Your Bones (Jump to section)
00:50:40 - Tips for Swimming Alignment (Jump to section)
LINKS AND RESOURCES MENTIONED IN THE SHOW
Stay Moving on the Sidelines Article
Swimming Alignment & Head Ramp
Eye Adaptation in a Southeast Asian diving culture
Eye adaptation underwater training in children
Arterial Stiffness in Japanese Pearl Divers
Cold Adaptation in Korean Women Divers
Marine Resource Use in Neanderthals
Video Clip of Swimming Head Ramping Demonstration
PODCAST TRANSCRIPT
(Theme Music)
This is the Move Your DNA podcast, a show where movement science meets your everyday life. To make sure you don't miss an episode and keep up to date with what is coming up, be sure to follow or subscribe to our podcast wherever you like to listen to audio. I'm Katy Bowman, biomechanist, author, and water aerobics instructor. And I'm Jeannette Loram, biologist, movement teacher, and retired swim coach. Everybody is welcome here. Let's get started.
JEANNETTE: So last month we talked about hiking and we talked about how swimming was a really good movement pair with hiking. So we thought it would be really nice to do a full episode, especially in summer, on swimming.
KATY: Especially with the Olympics going on. Are you watching the Olympics?
JEANNETTE: Exactly. Oh my goodness. Well, I have to say, I watched the swimming. I watched the swimming. I watched the diving.
KATY: What about the synchronized diving?
JEANNETTE: Amazing! Tom Daley, and I can't even remember his new partner, but it's so amazing. And the women, the timing. The timing is incredible. How they do it. I just do not know.
KATY: And this is a question for you and then everyone else out there to listen and send me their answer. Does anyone else - workout is the easiest - I feel like when I watched the Olympics, I'm not armchair watching the Olympics. I feel like, you know, my bar is out and I'm hanging. And I feel like I just need to do some pushups and I'm doing squats and stretching. I feel very ... inspired. Now, I also do those same things if I watch G. I. Jane or Rocky, you know, any sort of movie where physical prowess, just someone training, I'm very inspired in those spaces and immediately start doing those things. And I've noticed my kids do that too. You know, am I teaching them how to do it? Or is it just bubbling up from within?
JEANNETTE: Do you know what? I was watching the Olympics last week at my parents’ house with a whole bunch of people. And we all love the swimming. So I just grabbed the only space in this tiny room with 14 people. And I just lay on the floor and did a bit of stretching.
KATY: Yeah. Ok.
JEANNETTE: So I didn't actually do anything too rambunctious. But I definitely felt the need to move. It'd be interesting to know as well, whether there's kind of, an effect afterwards. Like do people carry that over because they're so inspired, having seen something? Do they start something new? Or does it reinvigorate their movement habits? Cause I think it must do.
KATY: Yeah. Or is there an uptick in even a registration for sports, you know?
JEANNETTE: Yes. My boys were watching ... I don't even know what they call it. It's like a stunt bike.
KATY: I feel like there are way more sports in the Olympics.
JEANNETTE: There are!
KATY: I'm like, did they just make this up? Like what is happening here?
JEANNETTE: Yeah. But I was blown away by these stunt bikes because they're jumping off the bike and they're twirling the bike beneath them and they're landing on it. And it's phenomenal. But I'm thinking, but little kids could, you know, who mess around on their bikes could see themselves in that. It's not just running. It's not just team sports. It's these things that kids love to do, just goofing around. So I think it must be inspiring. Yeah. But we'd love to hear viewers. What have you taken up after the Olympics?
KATY: I only have my own family to look around and think ... is this normal? And sometimes it's just stretching. I think it's just ... there's the juxtaposition between watching something so physically stimulating and being still doesn't work for my body. It's like a signal for me. I mean, even if I just get up and just stretch the entire time that I'm watching, I just can't watch other people being active …
JEANNETTE: and be still.
KATY: ... and be still. No, I mean, it goes for life sports also. I'm just not the sit-in-the-stands and watch-what-'s-going-on kind of person, I guess.
JEANNETTE: No. No that's true. I'm terrible with - my kids play rugby, but I just walk the dog round and I can't be ... partly I get so cold. But the idea of standing on the sideline. But B it's I can't watch somebody else move and have a great time and I'm just stuck there.
KATY: Well, and I did an article about that earlier on the blog about we're just kind of in a sporty time - there's summer sports. But then we're coming into fall, which can be a, a sporty time - of just how to get more movement. If you are a spectator, you know, or a parent. There's so much time with practice. Or games. I mean, sometimes hours. If you go to a tournament. Hours! And it's like, you know, feel free to walk. We definitely walked the dog. And I watched the game walking. And then I feel great. It's easier for me to actually pay attention ...
JEANNETTE: Yes. Yeah.
KATY: ... to the game just by moving around.
JEANNETTE: Yeah, absolutely. So swimming in the Olympics, what was your favorite? Have you, did you watch any?
KATY: I didn't watch too much of it. It was just the diving that I have seen. Yeah. We have this new book out and I feel like a lot of my work time - I've been doing a lot of interviews and so normally I might have - I feel like I don't want to be on the ... No, I just, I want to be outside. I want to be moving around a little bit more. But I feel still, I'm watching it all the time. But there's just so many sports. Like I called my grandmother who's 92 the other day. And she said, she just got out of the shower. And she said, I'm so sweaty, you see, because of the Olympics. She's like, I've been running and I've been jumping and I've been diving. She's like, I even shot off a few arrows this morning. And I just thought it was just the cutest thing that I'd ever seen.
JEANNETTE: That is really sweet.
KATY: Even grandma has, has Olympics fever. So we're gonna talk about swimming. You're a swimmer. So let's talk about our background swimming. You tell me about your swimming.
JEANNETTE: So I can't remember ever not being able to swim actually.
KATY: You don't remember learning?
JEANNETTE: I remember learning, but I could swim at that stage. I was very young when I could swim. I remember being in swimming lessons. And then I joined a swimming club. And I'm guessing I was seven or eight, that sounds about right, and swam competitively. And I dabbled in a little bit of open water competition, team triathlons. And I still swim. I don't compete now. But it's still my favorite sport. It's still my best sport. So yeah. How about you?
KATY: I have just always been a water baby. I do remember taking swim lessons. Red Cross swim lessons. I still have my little - My mom saves everything. She just gave me, you know - my little note card for completing my swim lessons when I was maybe four or five years old. And I didn't do a lot of, I mean, I had an open pool. I was never really a ... in high school I competed in classic strokes. But most of my time was just spent sort of, I don't know, water dancing. I'm not really sure what you would call it. It was just, is there a name?
JEANNETTE: Synchro? Synchronized swimming?
KATY: And I don't even mean that I just mean just me and this pool and creativity and creating lots of games. I used to bind my ankles together with a ring to be a mermaid and swim and I remember swimming along the bottom of the pool for hours coming up and then going back down. And doing all these things with my shadow in the water. And practicing deep dives. So not really swimming back and forth until I got into high school. And then I was on the swim team there for pretty much all my entire time at high school. And then, Yeah, I still swim. I prefer open water. I did some triathlons too. And I've always just been a strong swimmer. I will just hike up to a lake and I will have no problem swimming across a full lake ever. It doesn't matter how big it is. Like my confidence in my swimming is really strong. But never really for speed or paying attention to particularly good form with swimming like that good competitors will do. It's just more free form. I like moving across big bodies of water. Like swimming in the ocean. And I like swimming in wild spaces - in rivers even. I like to find - we live in a very riverous place - and I love to find spots in the river that kind of create this infinity lap. And I'll just, you know, swim in place in this cold river for an hour and I'll just do that. And that's also a pleasure, still today.
JEANNETTE: Yeah. Lovely. Yeah.
KATY: So that's who's giving you your instruction, folks.
KATY: Yeah.
JEANNETTE: At the beginning. So early swimming, early human swimming.
KATY: Yeah. Are humans swimmers?
JEANNETTE: Yeah. It's a tricky one.
KATY: Well, obviously we are. I mean, humans swim. But what do we mean by that biologically? Like, when you're classifying or categorizing animals and their traits, are humans swimmers like other animals are swimmers?
JEANNETTE: Yeah. This is a tricky one. And because obviously human infants and people who are not instructed in swimming can't swim.
KATY: Yeah.
JEANNETTE: Humans have to learn to swim. And actually, most other animals can swim. Without being taught to swim. Quadrupeds, you know, dogs, cats, they can swim without instruction. Which makes sense. They are quadruped animals. Their movement patterns can just, from walking, can just be translated to the water and they can get through the water safely. Whereas humans are obviously bipeds. So our movement instincts don't naturally translate to being able to swim. So we are not, I would say, we are not born swimmers.
KATY: No.
JEANNETTE: Yeah.
KATY: What other animals - are there other animals that are not born swimmers? But I definitely feel water is so important to humans and swimming is so important to so many cultures.
JEANNETTE: For sure.
KATY: So what are other animals that are ... like the water environment is very important to them but that don't qualify as born swimmers?
JEANNETTE: Interestingly, otters, actually. Otters - they can swim very young, but I don't know if you've ever seen footage - and everyone should go and Google this right now because it's possibly the cutest thing you'll ever see - is actually a mother otter teaching her otter. Is it pup or is it...?
KATY: I think It's a pup.
JEANNETTE: I think it's a pup. They will drag them in by the neck, you know, by the scruff, and actually swim with them. And then they'll pull them back out, you know, with the tail and they'll keep doing that. So it's interesting that it's not actually ... So I don't know, because most quadrupeds will swim at a certain age, but definitely otters' mothers teach their pups. So that's an animal that you would classify as an aquatic animal.
KATY: That's right. I mean for sure.
JEANNETTE: I mean, they do spend time on land. But I think if you were going to categorize them, you would put them in the aquatic camp.
KATY: Right. So being taught to swim doesn't necessarily make swimming part of you, like part of your species definitions or not.
JEANNETTE: Right. That's right.
KATY: Although there are probably no otters that don't swim.
JEANNETTE: That's right.
KATY: And there's plenty of humans that are not swimmers.
JEANNETTE: Plenty. I mean, you might not be near or live... You know, if we look back from time, there might be no significant ... Or it might be water that is so dangerous you wouldn't go in it. I'm thinking about predators or just very fast-moving rivers or whatever. So I think that's the interesting thing. I think if you look at swimming history, it's waxed and waned...
KATY: Mm-hmm.
JEANNETTE: ...in its importance to different cultures.
KATY: Well, it's back to trade off too, right? Like when is swimming... Swimming for pleasure is a completely different thing.
JEANNETTE: Of course.
KATY: Although I imagine swimming could be pleasurable, you know, for thousands and tens of thousands of years. But as far as it actually being functional and part of surviving in a landscape there just might have been the need to develop the skill and then if your survival didn't depend on you learning how to swim ...
JEANNETTE: You might not have done it.
KATY: ...then you might not have done it.
JEANNETTE: Yeah.
KATY: I do think it's interesting. We have these puppies that we're at the tail end of puppies pun intended. And we took three - Water is just really important. We taught our dog how to swim because actually, not all, I mean, yes, I think that all canines can swim, but some dogs have been ... because dogs are...
JEANNETTE: Their breeding.
KATY: ...they're shaped by people, you know. There, there are some breeds that swimming isn't automatic just due to their particular shape. So, if you have a dog, you know, just be mindful of that if you're taking it to the water for the first time. You can look up which breeds don't swim as well, or they can't sustain a swim. But this puppy that was with me, 10 weeks old, just went charging down the dock. This is the one puppy that is so curious. He flung itself off the end of the dock. Just had no problem jumping three-foot drop into the water. And I just stood there. Watched it go in and then it popped up and it just started swimming and it just came around and got itself to shore. I was, you know, prepared to go in there...
JEANNETTE: Rescue.
KATY: ...with it. Yeah, it's like my, my body was getting in that motion and then I was like, okay, Right. So That's the difference between a dog and a baby.
JEANNETTE: Right.
KATY: Because I think a lot of people will think humans can swim. Because there are these videos of babies underwater and there's that reflexive coordination of the limbs, that sort of doggy paddling motion that you see. And maybe even the tendency to hold the breath, but it's not able to swim on its own.
JEANNETTE: That's right.
KATY: You can't put a baby in there and have it come up.
JEANNETTE: And I think this is a little bit of a myth, you know, the swimming babies, because they do this coordinated limb movement, flexion of the...
KATY: It's a stepping reflex.
JEANNETTE: It's a stepping and it's crawling, but it's not actually swimming. And that reflex is present in lots of infant mammalian species that are tested. If you put anything in it, you will have these reflexive motions. But that's not swimming.
KATY: No.
JEANNETTE: It's just basically not making a fuss while drowning.
KATY: Yeah.
JEANNETTE: So that's really important. And the breathing, the holding the breath, that is part again of a mammalian... well, actually really almost all vertebrates, actually, not just mammals. There is what's called a diving reflex. But that happens in all species, not just, you know, swimmers. So that's important, I think to clarify. Yes. And I don't want to get too much into this, but there was a theory that was first introduced in the 1960s called the aquatic ape hypothesis. Which basically suggested that at some time in our evolutionary history, the ancestors of humans kind of diverged into a different evolutionary path. And really had an aquatic phase in our history. But really the evidence does not support that. It's not really considered a valid hypothesis, either in terms of evolutionary anthropology or biology. So, we definitely were not - we haven't had this kind of aquatic phase, but that doesn't mean, as we've already said, that swimming and water has been highly important to different cultures and humans at different times in our history.
KATY: Okay. So humans aren't "swimmers" with air quotes but we swim and we are swimmers. And so let's look at now the story of humans as swimmers. Culturally. As cultural swimmers. When did that start?
JEANNETTE: Well, it's interesting. There's some evidence from - we're talking tens of thousands of years ago. Actually a hundred thousand years ago for Neanderthals - there's some evidence in some very early Neanderthal and Homosapien populations. So that's modern humans that they did ... there's a, there's an incidence of what we call surface ear. Now, I know we did a podcast all on these type of things. But in this condition, there were these bony growths in the ears. They're called, let me get this right, you might correct me, exosto, ex, stosis,
KATY: Exostosis?
JEANNETTE: Yes. And that often happens in surfers, you know, when you're in a lot of cold water. But it can also happen in cold air. If you're repeatedly exposed to certain irritants. So it's not proof that they were swimmers. But these have been found in populations 100, 000 years ago, kind of 30, 000 years ago. And it's a suggestion that diving or water immersion was important. The other thing that I found fascinating was with Neanderthals, that they've actually found clamshells. So clamshells were used as a tool and they found a lot of clamshells that have evidence of erosion on the surface. So they've been collected when they're dead. Like they've been on the beach. They've been rattled around. But at least a quarter of the clamshells seem to be smooth. So it means they've been collected alive.
KATY: Fresh. Mm-hmm.
JEANNETTE: Fresh. And these clams, they can occur on sandbanks or something, and you could maybe wade and get them. But there is the thought that actually that they might've been dived for.
KATY: Ok.
JEANNETTE: So those are kind of very, very early hints that in certain cultures of different human species, water and diving may have been occurring. And then we have a big jump to when actually we started getting recordings. So imagery. Imagery of swimming.
KATY: Yeah.
JEANNETTE: So if you've ever seen the movie, The English Patient, the cave in that movie is the cave that's featured. And it has this wonderful, imagery of animals and people. But it looks like some of the figures are swimming. And this was about I think around 9,000 BCE. So we get this imagery. Now, they could not be swimming. There's no water in the picture, but that's the first hint. They seem to be doing kind of a front crawl motion. And then you can jump and we see imagery in Egyptian hieroglyphics, you know 3000 BCE. So we're starting to see definite imagery. And then you can tell it's water cause you've got fish and you've got other things that prove that what these people are doing IS swimming.
KATY: Moving through the water.
JEANNETTE: Moving through rather than floating. So for thousands of years, thousands of years, people have been swimming and recording their swimming. So it's clearly important to them.
KATY: Okay. So I know that a lot of people want to know about ... Well, one of the questions that we got was about swimming and the movement diet. You know, especially now as I've introduced this idea of macronutrients and micronutrients. What about swimming and mechanics? Overall, I tend to put swimming in the climbing and clambering category.
JEANNETTE: Right?
KATY: Because it's really ... it is a form of locomotion. I think that there are a lot of definitions of locomotion that tie it to terrestrial motion. But if you just think about locomotion and getting from point A to point B, the way you're using your limbs is not that different than the way you use your legs moving over ground. You know, you're digging in and you're pushing back. And that's what's happening with swimming, except you're using your arms and your legs. So definitely if you're a swimmer or you're swimming I would mark that you would be getting that macro category of climbing and clambering. Certainly the loads are lower, which is what makes swimming great. You know, there's a difference between climbing and clambering up a hill on your arms and legs, or doing a pull-up. The pulls are a much greater force. But you can get quite a bit of volume of arm use. And there's certainly musculature involved. Pulling water for a long time is, exhausting.
KATY: It's exhausting. So now that we've thought about it as a category, let's think about swimming in terms of its body parts. But when we talk about body parts there's interesting things that show up in swimming cultures. I mean, so all humans have the ability to learn how to swim, we'll say, but some cultures are very water-centric.
JEANNETTE: Right.
KATY: And there's some cool stuff that happens in their bodies. Whether their bodies are shaped by swimming or it's been selected over time.
JEANNETTE: Right.
KATY: So let's talk about those folks. Because I've always loved, especially the adaption, the adaptations of the eyes.
JEANNETTE: The eyes. Yeah. So, you'll probably be talking here about, I don't know how to pronounce it, the ba-bajau there, there's a ...
KATY: In Thailand?
JEANNETTE: Yes in Southeast Asia. And these are really, I guess, marine hunter-gatherers to a large extent.
KATY: Yes. Right.
JEANNETTE: That's their way of life. So these people are swimming for their resources and diving and fishing. And there's definitely been some - so the children, especially, have improved underwater eyesight. I don't know too much about the adaptations, which you may do, but the really interesting thing that I read about recently was that is actually trainable.
KATY: Yeah, that's right.
JEANNETTE: Because they've been able to do that with a cohort of ...
KATY: European children.
JEANNETTE: ... European children.
KATY: But only children, not adults.
JEANNETTE: Yes. Right. There's obviously a window.
KATY: Yeah, I've been looking at this for years, because I think it's so interesting. You know, usually, when you go into a darker room, your pupils dilate to let in more light. So when you go underwater, and if, you know, imagine you're diving for seafood, pretty low, you're in a low light environment. And so the automatic response of the eye, you don't have to do it, is for the pupils to dilate. But when you dilate, your vision is pretty fuzzy, which does not help with hunting.
JEANNETTE: Right. Especially underwater when it's already...
KATY: Especially underwater. So you're like murky and you know, you're in low light. So your pupils want to dilate to let as much light in. But now you can't see clearly. And so what these people are able to do is override that dilation and they can actually constrict on command. So they can constrict their pupils to actually let in less light, but then keep the clarity of vision.
JEANNETTE: So are you saying this is a decision? Like it's not a reflex?
KATY: It's a choice.
JEANNETTE: It's a choice. Wow.
KATY: I feel like it's very similar to a lot of the cold water immersion where there's the natural reflex of the body, but then you can learn to control and maybe even turn off the reflex with a lot of mindful awareness and practice. So they figured out the way to not only not dilate, actually constrict.
JEANNETTE: Yeah. How do you even start to figure out where your eye-constricting muscles are? That's insane.
KATY: I don't know! But I feel like that's what a lot of these ... What so much of these outlying cultures, I don't want to call them outlying cultures, but cultures who have this unique skill, people who develop this unique skill is they've figured out the equivalent of lifting one eyebrow.
JEANNETTE: Right.
KATY: But for these, you know, seemingly only autonomic functions, like there's some somatic control.
JEANNETTE: I have a question. Do they teach the children? Do you know?
KATY: I don't know. I don't know. That would be a good question. And then there's one more thing that they do with their eye is they also, they can change the shape of their lens. It's it's the same process of accommodation focusing. So they're also able to change the shape of their lens to really get the focus that they want.
JEANNETTE: Ok.
KATY: So they just have more control over the movement of the eye than maybe people expect to be able to have. And it's probably engaging in an environment where, you know, maybe it was happening and they felt it, or they felt the change and figured out how to stop it. And I mean, I imagine it's been going on for hundreds if not thousands of years. And so I, that's the eye part, but then there's also the spleens.
JEANNETTE: The spleens. Yeah. So your spleen it has a reservoir of oxygenated blood cells. And this is actually part of the mammalian diving reflex. And it's particularly pronounced in diving mammals like whales and things like that. You get this contraction of this spleen, which releases - you get an extra bit of oxygenated blood cell to last you that little bit longer in your dive.
KATY: So the spleen actually is not static.
JEANNETTE: No.
KATY: I mean, is it static - I mean, would we say it's static in us?
JEANNETTE: I guess. That's a good question. I don't know that. I would think not because I think - I'm saying that because I think in the populations they've studied the changes in spleen size - so you can get more out for a given contraction. So I would think the contraction is a conserved trait and we would probably have that if any of us... because it is part of that deeply programmed dive reflex. That's my guess, but you know, I may be wrong. So this population of marine hunter-gatherers, the Bajau - I think that's how you pronounce it, this eye thing is a trainable effect.
KATY: Right.
JEANNETTE: What seems to be a genetic adaptation is their spleen size. So they have actually found that over generations, there's a genetic difference and it's been selected for this increase in spleen size.
KATY: So it's not like a - their spleen muscle isn't getting larger with use. It is just over time you're going...
JEANNETTE: No. Well...
KATY: to do better. Perhaps a little bit?
JEANNETTE: ...with science, it's very difficult because they're looking at one thing and one, one gene, and it may be there are other things going on too. But they have definitely found a genetic adaptation in spleens for this increase in spleen size. There might be other things going on with the training of the spleen. There's nothing that I found in the literature yet on that. So, yeah, so it's very interesting. They have both these genetic adaptations and some trainable kind of, improvements, I suppose you'd call them.
KATY: I wonder how your spleen is. How's your spleen?
JEANNETTE: I have no idea. I'll tell you, I lived in a subtropical island for many years and did quite a lot of free diving. So maybe? I was never particularly good or competitive with how long I stayed down. So I have no idea.
KATY: Maybe you have a tiny spleen
JEANNETTE: Maybe I have a tiny spleen. Who knows?
KATY: You need a spleen of a whale.
JEANNETTE: Yeah, I know, exactly. So yeah, that's the Southeast Asian population that's interesting. And the other culture that's really interesting are the Korean and Japanese pearl divers.
KATY: They're women.
JEANNETTE: Which are mainly women. Well, actually they are now all women. I think back in the day, like the 1800s, I think in Korea at least there were quite a lot of men and there seems to have been a shift. But yes, they are. I think in Japan, it seems to have been women for a long time. Yeah. So they have some interesting adaptations too. So they're diving in quite different conditions. They're diving in cold water. But I had to laugh. I laugh because their winter temperature is about 13 to 14 degrees C, which is the same as the summer temperature here.
KATY: Yeah, that's right. I mean cold's relative.
JEANNETTE: So it was all relative. I'm like, it's cold in summer here. So it's pretty cold. So their adaptations are more towards dealing with the cold.
KATY: Yeah, like thermal regulation, body fat.
JEANNETTE: Right. Yeah. The interesting thing about fat - and you might know a little bit more about this - but certainly in the Korean women, they are no more fat than the general population. In fact, they're leaner than the general population. So everything I have read seems to be that their ability to -what we would call their peripheral insulation seems to be more to do with their circulation than with actually fat.
KATY: Which is still to me movement. Right? So much of that ability to thermo-regulate is about moving blood.
JEANNETTE: Yes.
KATY: I mean, you know, you wonder about the arterial walls.
JEANNETTE: They've found, actually, that the pearl divers in Japan, they have less arterial stiffness...
KATY: Mm-hmm. That's right. Because they are...
JEANNETTE: ...than the general population.
KATY: It's like the spleen, you know, like you're asking it to do something. You know, the same reason that I really like to submit myself to colder temperatures. Because I feel like my ability to warm and cool myself based on my environment is a movement that's only trained in - like the temperature is the variable that triggers that movement or not. And also I feel like I'm very practice - I mean, I certainly have plenty of body fat. But I can be in cold waters for a very long period of time. And I feel like I'm warming myself by moving my blood in a certain way.
JEANNETTE: Maybe. I wonder - so have you heard of the idea of a counter-current in terms of blood? So the best way is how I learned it in probably high school biology. So if you think of a bird with long legs - an Arctic bird. Obviously, they've got these skinny long legs. And they don't succumb to any kind of hypothermic issues because they have a very well-designed circulation system to the feet. So if you imagine the blood vessels kind of lined up. So I'm holding my hands up. And you've got the blood coming down that's warm from the heart. And that butts up against the cold blood that's coming back up from the feet. Now if you have them arranged close together, the hot blood can give its heat to the cold blood that's coming up. So it stays. It stays within the center of the body and preserves that heat. And then the cold blood goes to the feet and it can't lose as much heat. Does that make sense?
KATY: Yeah. It's like the warm blood's almost the insulation.
JEANNETTE: That's right.
KATY: Like it's an extra layer of insulation.
JEANNETTE: That's right. And that's what they think goes on with the pearl divers - that they've got some efficient counter-current system, which means that they don't lose as much heat from their body as non-trained people from that culture.
KATY: Yeah.
JEANNETTE: The interesting thing is how that happens, whether it's as they're developing. Because often, I mean, many of these women that have been doing it ... So now they have wetsuits. So that kind of is changing things.
KATY: Has there been a loss of, I wonder, a loss of adaptation?
JEANNETTE: It has been a loss of adaptations. So they used to wear these thin cotton suits. And the ones that are now, I guess it was the seventies, wetsuits came in and they have lost those adaptations. But these women that probably are now in their eighties, nineties, that we're doing it back in the day they, they started very young. So it's interesting to to wonder how plastic their circulation, how their blood vessels were laid down, whether that is very plastic during development.
KATY: Well, and the same thing goes when I talk about the eyes. You know, you can't keep really easily changing the shape of your lens. It is something that has to be learned in childhood. You can't learn it as an adult because things are stiffer and more set. So yes, I do think that juvenile period, you know, the period of our childhoods are so important in setting our adult body. And in the case of these sort of extreme outlying things, I mean, I don't know if temperature regulation is extreme. But certainly submerging yourself in water, in deep water is something that's not likely to come up. But, anyway, yeah, that's exciting. I love water. I love water.
JEANNETTE: Yeah. Me too.
KATY: I just love it, I can't imagine.
JEANNETTE: I'm at my happiest in it for sure.
KATY: Yeah.
JEANNETTE: Although I am not good in cold water. I used to be better. And I'm a lean person.
KATY: You're very lean. And you're leaner now as you get older?
JEANNETTE: I think I am. I think when I was a kid, I was not so lean. I think I was, yeah, more robust.
KATY: Sure. I mean, the youth comes with all that extra fat and padding.
JEANNETTE: Yes. And I didn't use to suffer from the cold so much. I think eight years on a tropical island ruined me as well.
KATY: So there's lots of adaptations that you could have had. That's right. Will you use a wetsuit now?
JEANNETTE: I do.
KATY: Yeah.
JEANNETTE: Yeah, I do.
KATY: Wetsuits are pretty great. As are dry suits, depending on what you're doing.
KATY: All right. So now let's talk about alignment and swimming and micros. So you're a swim coach, retired.
JEANNETTE: Retired. Yes.
KATY: But always able to come back out at any time.
JEANNETTE: I know. I know. And I do. I get the occasional, "please come back". So I do.
KATY: And so there are these classic strokes.
JEANNETTE: Right.
KATY: And so when people are asking me about how to check the box for micronutrients, let's talk about these strokes and how to think about the shape: the constellations of swimming, if you will. So what are your primary strokes?
JEANNETTE: We have front crawl - sometimes people might call it freestyle, but that's actually slightly technical. But when you've got the one arm and then the other arm overhead, that's front crawl. Same on your back, backstroke, similar. Those two strokes are known as what we call a long-axis stroke. So if you think of a line bisecting from the top of your head down the middle and you kind of rotate around. So it's a long axis stroke. And they're also asymmetric. But you're not doing the same thing with both arms and both legs.
KATY: At the same.
JEANNETTE: At the same.
KATY: You're doing it the same time. but it's sort of staggered.
JEANNETTE: Staggered.
KATY: It's like walking. Walking is opposite sides are doing different things.
JEANNETTE: Right. And then we have what we call the two short-axis strokes. And they're also symmetrical. So both arms are doing the same thing. Both legs are doing the same thing. And that's butterfly, the stroke that makes you feel like you're going to drown. And then breaststroke.
KATY: Yeah. What's your stroke?
JEANNETTE: I was a breaststroker actually. I was a breaststroke specialist, but I love backstroke and front crawl too. Butterfly is my least favorite.
KATY: Isn't it everybody's though?
JEANNETTE: Well...
KATY: Aren't you just mostly, I mean, my friend Jess is an amazing Butterfly. I mean, I did the, IM, and so, you know, did a little bit of everything. And I'm a breaststroker also. Although I'm not a breaststroke specialist, so I'd like to see that business card. Although aren't we all? Anyway yes, I feel like my butterfly goes nowhere. But you would call these ... what's the other axis?
JEANNETTE: So it's short-axis.
KATY: Short-axis.
JEANNETTE: So you're thinking about through the cut through cut yourself in half.
KATY: Cross-pelvis.
JEANNETTE: Yeah. And that and those, those strokes are more - the kinetic energy comes more from the hips.
KATY: Mm-Hmm.
JEANNETTE: And with the long-axis stroke with front, full, and backstroke, it's more through rotation. Which is actually what a lot of people don't get when they're swimming. They kind of use their shoulders a lot and it gets really tiring.
KATY: So those are the main strokes. Although I would also say sidestroke is a big one.
JEANNETTE: Yeah.
KATY: You know, that people, you know, there's Combat Sidestroke, which is a, a military swimming ...
JEANNETTE: Oooh! What's combat sidestroke.
KATY: Combat sidestroke. You'll have to look it up. It's a way of moving swiftly through the water while potentially carrying a load...
JEANNETTE: Okay.
KATY: ...while maybe needing to keep a little more awareness of what's going on around you. And that's actually the stroke that I - I really enjoy side stroke.
JEANNETTE: I do, yeah, I actually do quite a lot of sidestroke when I'm in the ocean, particularly when I'm with my kids.
KATY: Mm-hmm.
JEANNETTE: Well, my, younger kid who's a slower swimmer. So I'm kind of watching him. And actually, because I naturally have - I find it easy to get my alignment in the water. A wetsuit can actually lift me up too high.
KATY: Mm-hmm. A little buoyant. Yeah, right.
JEANNETTE: I'm a little too buoyant. So actually swimming on my side, I do a lot because of that. It's easier in a wetsuit when I'm just wanting to - I'm just playing and I'm watching my kid. So, yeah.
KATY: Yeah, it's not particularly - there is a more efficient versus a less efficient side stroke. So you can always work on efficiency. But as far as moving quickly through the water, I think you're sacrificing, you know, like if you're crawling through the water, doing freestyle, you're just like a machine, you know, moving through the water. Where I feel I'm spending more time taking in my surroundings. I like sidestroke for the observation. A lot of times when I'm swimming, it's not just the swimming. It's enjoying the environment or maybe being with someone, chatting with someone, you know, the whole time.
JEANNETTE: Yeah.
KATY: And then also, I want to call it freestyle, but there's no formless swimming.
JEANNETTE: Yeah.
KATY: You know, like I was talking about, you know. And when we come to plotting the constellation this one's gonna be - you're gonna have to look at yourself in the shapes that you make, you know, when you're ...however you end up moving through the water, there's, you know, dog paddling so-called or treading water. And all of these, I think fall under the umbrella for most - non-competitive performance folks - just swimming. It's being in the water and staying afloat in the water. So there's all these shapes to think about.
JEANNETTE: We have a phrase manatee-ing because that's what my kids do a lot. They just, they manatee around. They're just like leaping out and playing. And so their constellation is probably wonderful because of all their manatee-ing.
KATY: And I think manatee-ing, now that it's a verb, is also just learning how to deal with your own pressures. There's a certain amount of skill of - you're arching your back in a particular way. There's a little bit of movement involved. But there's also a lot of floating - knowing how to hold pressure in your trunk that allows you to minimize the work. Which is great if you're a kid and you're just, or anybody, you're just in a pool or a lake or a body of water all day long. You don't necessarily want to be working hard where you would if you were using it for exercise or conditioning. So it's a spectrum of the reason that we use swimming or water play.
KATY: All right. So how do we chart? What are some general ways that we can have people chart their swim stroke?
JEANNETTE: Their swim stroke.
KATY: We already know it's a macro.
JEANNETTE: we already know it's a macro. So I would - if they have your book, cause that's there, you've got the micronutrients page.
KATY: That's right.
JEANNETTE: Which I think is really helpful. And I can't remember how many there are. But what I did when I was thinking about today's episode is actually go through them and say, "okay, well". And you've got these micronutrients for people to say, "okay, these are important ones that I need to look at how much I'm getting."
KATY: Right.
JEANNETTE: And in there, you've got dynamic arms. So swimming ticks that box for sure.
KATY: Yeah. Sure.
JEANNETTE: And you've got lots of overhead arms, which we don't get a lot of. So dynamic arms are in there. And also I should say with the exception of breaststroke, all classic strokes are upper-body dominant. So if lots of your other movement is lower body dominant, swimming is a great way to switch it up.
KATY: Especially if you pick strokes other than breaststroke.
JEANNETTE: Especially if you can do that. Yes. Then we've got dynamic hips.
KATY: Mm-hmm.
JEANNETTE: We've got flexion/extension. And then in breaststroke, we've got that abduction/adduction, where you're taking your legs wide and close together and rotation. Rotation of the femur is really important in breaststroke. So we've got that. You've got dynamic spine.
KATY: Mm-hmm.
JEANNETTE: We've got flexion and extension in butterfly. And we've got rotation in backstroke and front crawl. So if you're, if you're charting it, it's worth, I guess, looking at what your swimming looks like. Because if it's all breaststroke, you might be able to make your swimming more nutritious by adding some of the other strokes in. What else do we have?
KATY: I also think ...
JEANNETTE: Sorry, I was going to say heart and lungs, but carry on.
KATY: Heart and lungs, for sure. Like, this is an excellent low-impact cardiovascular movement. And you can get it through these strokes that we talked about. But a lot of people will just use the water aerobics. I mentioned earlier I am a water aerobics instructor. I taught it years and years ago. But it was such a great medium if you're dealing with injury. Because it's a buoyant environment if you are working on building muscle mass and you're non-lean mass exceeds your lean mass and you're struggling to move on land to the volume that you would like, water is a really great environment to work on cardiovascular fitness.
JEANNETTE: And if you have knee issues - knees don't, that don't like ...
KATY: Yes, or low back.
JEANNETTE: Low, low back. Yeah.
KATY: Yeah. It's really great. It's a very forgiving medium. And it's a really great place to start or rehabilitate. When I fractured my foot, I went to more swimming, you know, to be able to keep moving a lot of other parts, but without aggravating this particular injury. And same thing if I hurt my back or my back is stiff, I will go in and do these modified swim sessions to almost stretch out parts of my body. I'll use water to stretch. And I don't mean going in, just stretching in the water. I mean, putting myself, you know, on one side, like a side stroke. And when you have these kicks where one leg goes forward and one leg goes back, I wrote up an article about this years ago. I noticed 15 years ago that on a side stroke, my left leg would go in front and my right leg would go back. And that did not change when I went to my left side. Meaning even though I was rotating the position of my arms, I was not rotating the dominant kicking leg.
JEANNETTE: Interesting.
KATY: And then once I clued in, it's like, of course! Because I don't like to put my left leg back behind me because that's my tighter hip flexor. So by choosing that mindful stroke awareness, it helps me stretch out that tight left side. If my sacrum is a little bit wonky or feeling twisted, I can use this slow - movement slows down in the water.
JEANNETTE: Yes. Yes. Because you've got that...
KATY: You know what I mean?
JEANNETTE: ...resistance.
KATY: Yes, it's just a whole different type. And there's weights that they use in water, which are just foam tubes. So then you push them down and it increases the resistance. So there's actually these strength training things you can do in the water. You can be in deep water. And if you've never explored it before and you were just wondering what else you might do, don't be afraid to look to the aqueous environment.
JEANNETTE: Absolutely. I have a question for you about your foot. When you were in the water with your foot injury, did it bother you to kick or did you just not kick and just pull?
KATY: I did kick. For me, mine was very much related to weight bearing and pressure on a certain part of the foot. It wasn't really related to plantar flexing or just pointing my toe, which some people's foot injury might be. And there's a lot of plantar flexion. Probably one of the reasons I like breaststroke is because you get into some dorsiflexion.
JEANNETTE: Yes. The only stroke with that, right.
KATY: I think I really gravitate towards breaststroke because it is the balance of so many things. If you think of your head down on a computer, you know, or reading or whatever. Yeah, like there's some, extension. Now there's supposed to be some thoracic and cervical extension. A lot of times it ends up being all cervical extension, which is something we can talk about in a little bit. So minding spinal curve there. It took my hips in a completely different position than walking or sitting down does. It's one of the only strokes that has that. Side stroke too, can get you - the way that I side stroke. Or if you look into some of these like the combat side stroke, like there's just some different hip motion that happens. And just big arms. Big arms moving out to the side versus out in front of you. So for me, it's a very movement, diet, balancing...
KATY: ...activity. That particular stroke. Not just swimming overall, but that particular stroke. We should talk about bones.
JEANNETTE: Yes. Because however much I love swimming, there are some things that - some micronutrients - that it's missing. And weight bearing is one of them.
KATY: A big one.
JEANNETTE: Because obviously you are not ...
KATY: Which is what makes it so good. That's what makes it so good.
JEANNETTE: Right.
KATY: So it's not good or bad. It's just not weight-bearing. And sometimes you need that. And sometimes you don't.
JEANNETTE: That's right. It's great, if you want to do some heart and lung movement that doesn't stress your joints. But your bones need to be loaded to get stronger and swimming does not do that. And there's been loads of research, mainly on swimming athletes, which are outliers in themselves because of what they ...
KATY: High volume of primarily swimming.
JEANNETTE: High volume. And that's the key, I think. Because there's this data that shows that swimming athletes have either the same or even lower bone density than control healthy, but sedentary, population. But they don't think that swimming - like swimming's not doing anything like leeching...
KATY: Swimming is not leeching the minerals from your bones. No.
JEANNETTE: No, it's the fact that collegiate swimmers are spending 20 hours in a pool. And there's no time for any weight-bearing exercise. Because they're so, I mean, presumably exhausted. And, you know, they've done so much movement. So it's really a time thing that they're not doing the movement that...
KATY: Their movement diet just isn't balanced.
JEANNETE: Yeah.
KATY: You know, they're just taking a lot of swimming food.
JEANNETTE: So yeah. So swimming needs to be, you need to do some weight bearing movement too.
KATY: Yeah. So that's a good way of - you know, walk to your training session.
JEANNETTE: Right.
KATY: Or a lot of times now I think that in sports, or athletics, there's a more understanding of how to train outside of doing your sport.
JEANNETTE: Yes.
KATY: It was all so specialized back then. It was this idea of like, you want to do something good, then do it as much as you can. But I have seen more stories on the Olympics this year. And I feel like there's been some high profile professional athletes who've been able to have longer careers because they really...
JEANNETTE: That's right.
KATY: ..took to better, broader training. You know? And so if you are thinking, if you do have children that you want to put into the athletics, and there's this idea that's early specialization, is just to recognize that that doesn't necessarily make you better. There's a certain amount that you have to do to be competitive. But that your movement diet overall needs to be looked at. Whether you're an athlete or just someone who moves every day, but that movement is always in the pool, you're going to want to be watching your bone and you're going to want to be not necessarily mixing modalities of exercise - maybe swimming is the exercise that you love. But then outside of your swimming time, you want to be doing things that really challenge your bone loads.
JEANNETTE: Right.
KATY: Wear your heavy backpack to the pool.
JEANNETTE: That's right.
KATY: And walk in.
JEANNETTE: Yeah. And I think you're right that these days swimmers are doing - because I think it used to be swimmers were perhaps the ones that were doing the most hours of their sport specific. And now there's a lot of weights. And I think you're right about the longevity too. I mean, Katie Ledecky, who is now 27 and still... I mean that was really old for a swimmer back in the day and it's not anymore, which is great.
KATY: Careers are getting longer overall by recognizing that you don't specialize early and then you don't even specialize when you're doing your sport. And that this more balanced approach is how you're able to do the thing that you love and find meaningful longer.
KATY: Yeah. So let's talk about alignment and strokes. So, you know, in the same way, when you get out of your chair - I've talked about this before - you're leaving the seat. But maybe there's adaptations in your body that you're not completely leaving behind. And so two of the ones that we can talk about that I know that are very common is that increased hyperkyphosis, extra curve of the upper back. And then also the tendency for the hips to be particularly tight. Where we're so used to having our hips flexed that when you swim, your legs are stretched out behind you. But sometimes that tight hip means that when you stretch your legs back behind you when you swim, you also tilt your pelvis in a way that can compress your lower back. So just getting in the water and being face down with your arms stretched out in front and your legs back behind you can set you off before you've even swam a stroke. Now you're in a little bit of too much lower back compression and too much cervical compression before you've even done anything. And then the stroke now has you kick your legs back and forth. Or if you're doing the butterfly, you're actually undulating your pelvis up and down. You're flexing and extending your lumbar spine. And if you are doing breaststroke, where you're picking your head straight up out of the water, and I think butterfly too, where you're coming straight up out of the water.
JEANNETTE: Right.
KATY: Now you've got extra compression in your neck and your lower back. So some things that you can think about is the good old head ramping exercise. You can find it on my website. We need the head ramping stickers go on the inside of your swim goggles or something like that.
JEANNETTE: Well, we have this horrible thing that we used to do with kids, which is put a tennis ball under their chin and you have to hold the tennis ball.
KATY: As you come up out of the water? I actually kind of like it.
JEANNETTE: Oh, it's great because I'm going to show from the side ...
KATY: Get your tennis ball! Get your orange. What do you have?
JEANNETTE: I have a tennis ball and you just hold it. And because I'm watching cause the - if you watch the Olympics, they won't move their - they won't lift their chin at all. Yes. There you go.
KATY: Okay. So look at, I have my mason jar lid. So I'll just show it. We'll put this video clip in the show notes because I do think it's such a visual thing. So if you have hyperkyphosis, you know, when you come up and you take a breath, it tends to be mostly at the neck instead of coming up from the upper back. So if you have something under your chin, As you come up, it's going to make you extend your thoracic spine a little bit more than your cervical spine. Now, if you're hyperkyphotic, this probably won't work for you in the moment. Because you can't just extend your thoracic spine if it's very stiff. So I would work on mobilizing the thoracic part of the spine, especially if you want to keep swimming and you're noticing ... A lot of people come to swimming later in life. I think we had a question - in our virtual studio membership, there was a question there about someone who was going to competitive swimming in their sixties, just starting out, and was asking specifically about the upper back. You know, to work on mobilizing the upper back and working on the back of the shoulders and strengthening - making the the extension of the upper back easier on you on land, so that it was less resistant to the movement in water. So you're not doing so many neck crankings. And the same thing for your hips. When you're in the water, instead of arching your lower back, to think about a little bit of a posterior tilt. So I don't know if you have to hold an orange in your ribcage?
JEANNETTE: I don't have anything. Yeah, I don't have anything for that. Let me think. What do we tell? Yeah, nothing. Nothing as easy as that.
KATY: No, no. So just the idea. I always think of - imagine if you're standing up straight, but you did a little bit of a sit up, but you didn't let your head or your legs go anywhere, your upper body would just curl up a wee bit, and if you have that tension there, then when you're kicking, your kicks can come more from your hips and less from your lower back. And that would, you know, hope to reduce some of the repetitive use issues that you're having. But remember that you always have the ability to cross-train. So you don't have to give up swimming, but maybe you need to vary your strokes. Maybe your warmup stroke and your cool-down stroke could be different than what you want to really practice for, for speed or competitiveness, even if it's just against yourself.
JEANNETTE: Mm. Brilliant.
KATY: I want to go swimming now.
JEANNETTE: I know, me too. I'm going to go tomorrow morning, I think.
KATY: That's wonderful. Well, we got to go backpacking. I was in the Olympics myself. Only it was the Olympic mountains this weekend.
JEANNETTE: Amazing.
KATY: And we backpacked up nine miles to have a full tarn, which is a lake in the mountains that's not really fed. It's just an ice melt. So it was turquoise. And just swam in this very cold tarn, you know, all by myself with just my daughter and her friend. There was no one else up there. There was just some, some 12-year-olds and, and me. It was amazing. For me, that is, when we talk about in My Perfect Movement Plan, the movements that make you feel joyful and connected to your body, connected to the bigger picture. It's always being in wild water for me that does that.
JEANNETTE: Yeah. And that's really why I became a marine biologist. I wanted to be in water and looking at stuff. Looking at stuff as I swim. And that's still my favorite, for sure.
KATY: And here you are on this podcast. Now you need a marine biology podcast or job. Forget the podcast.
JEANNETTE: Yeah. I …
KATY: Marine biology doesn't pay the bills though.
JEANNETTE: No. Well, academia is a different thing. Yeah. Unfortunately you end up spending more time in front of a computer just trying to get money rather than actually being underwater doing the fun stuff. And then the graduate students get the fun stuff. So...
KATY: Well, learning's not about the job. It's about what you know. And you're sharing your knowledge with everybody here today and in your own communities and your kids. And like, it's still amazing. Nothing's wasted.
JEANNETTE: No. So, thank you for that. That was great, as always.
KATY: Stay swimming out there, folks!
JEANNETTE: Stay swimming, yeah! Enjoy the rest of the summer.
(Theme music)
KATY: Yes. On your back. Looking up at the sky. Or the ceiling above your pool, whatever.
JEANNETTE: See you next time.
KATY: Bye.
Hello! My name is Rachel, a Nutritious Movement teacher from Wimbledon, London, UK. This has been Move Your DNA with Katy Bowman, a podcast about movement. Hopefully you find the general information in this podcast informative and helpful, but it is not intended to replace medical advice and should not be used as such. Our theme music was performed by Dan MacCormack. This podcast is produced by Brock Armstrong. And the transcripts are done by Annette Yen. Find out more about Katy, her books, and her movement program at NutritiousMovement.com.
(Music fade)
