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Breathing in, breathing out
I ran, Tuesday night, probably the fastest 5K I have ever run. I don’t know how long it took. I didn’t time it. But I know that I started out at a good clip and thought “I’ll have to slow down to make 5K,” and then I didn’t slow down. I didn’t slow down, and I was at the top of the hill and running down the other side before I realized I had been climbing, and was a little disappointed when it came time to stop at the 5K point.
But stop I did, because it’s best not to over-train. That’s how you get the shin splints, the pronated ankles and blown-out knees, and I’m beginning again to think in the long term. The common advice is that when you’ve just started being able to run 5K, that each long run be followed by a day of rest.
So I only ran 2.5K on Wednesday afternoon. I ran a little slower, knees aching a bit at first, calves throbbing, and then — as usually happens when I’m not already distracted by work, or love, or heartache — my breathing rhythm filled my mind, and before long my legs felt loose and comfortable.
I time my breaths to my hoof beats. I start out at a measured pace, breathing in for four steps and out for four. When I feel a little bit of anoxia I move up to a three and three rhythm, IN (two three) OUT (two three), running and breathing in waltz time. These days I’m usually about a kilometer down the path when I again feel shortness of breath, and I move up to what has become my default, long-haul respiring rhythm, drawing deep breaths in for three steps and then exhaling forcefully in two. The hard exhalation raises the air pressure in my lungs, thus raising the partial pressure of oxygen, I tell myself, and I thus increase the efficiency with which my lungs extract that oxygen from the ambient air. I have no idea if that’s true, but it feels good. Heading uphill I will often find myself breathing faster still, a two-steps-in, two-steps-out rhythm, or even one and one if I am pushing myself too hard. As soon as the trail levels out I drop back to the three and two, usually without thinking about it.
It is often said, counterintuitively, that a man can outrun a horse. It seems stupid on the face of it, and in fact Olympic athletes have lost demonstration 100-yard dashes to near-senescent horses. But as PZ pointed out in a post about three years ago, that equine advantage dwindles when you lengthen the track. Quadrupeds are often excellent sprinters — I once, based on dead reckoning and guesswork, figured that the young Zeke’s “not really trying” fun sprints averaged around 25 mph — but not so good at the long haul endurance running thing. It is indeed quite possible for a well-conditioned human to outrun a horse in a race of ten miles or so.
The difference between sprinting and endurance running? Oxygen. In sprinting, you use up oxygen faster than you can breathe it in. It’s anaerobic exercise, and no animal can exercise anaerobically for very long. Endurance running is aerobic: you use only as much oxygen as you take in. Barring injury or hunger or stoplights, human endurance runners can keep going a very long way.
PZ’s post was spurred by a paper in Nature that postulated that much about the human body’s morphology could be attributed to selection for endurance running. He offers, in table form, a long list of human physical features that make endurance running easier, along with the service they offer the runner and the possible evolutionary points of origin for each feature. Of course, whether it was selection for running that sculpted each and every such feature is open to conjecture. It’s tempting to speculate as to the selective advantage of being able to run at moderate speeds for a very long time. It’s not much help when confronted by a jaguar 20 yards away intent on crunching on your temporal bone: the jaguar would find it fairly easy to outpace you, knowing it could relax and reoxygenate once it had made sure, by collapsing your trachea, that you couldn’t reoxygenate. But it’s easy to see advantages in running toward animals rather than from them (a.k.a. hunting), in warfare, perhaps in traversing bleak Miocene landscapes with miles of baboon-infested veldt between spots of suitable habitat.
Anyway, it’s a good post, and you ought to take the time to read it, perhaps ignoring the usual assortment of wise-ass Pharyngula commenters.
But I’ve been thinking, as I run, about one of PZ’s assertions in that post:
Just walking bipedally is a precarious exercise, and running amplifies the problem.
It’s true: compared to precarious bipeds, quadrupeds rarely find themselves doing face plants (though again, there are some Zeke anecdotes relevant here) and running makes the falling not only more likely but more spectacular. Some of the adaptations listed in PZ’s old post address the issue, such as our relatively larger inner ear organs.
But I wonder if our bipedalism might not be the reason we can run for such long distances relative to quadrupedal mammals.
This isn’t my insight, or it least it wasn’t until I borrowed it. In Peter D. Ward’s Out of Thin Air: Dinosaurs, Birds, And Earth’s Ancient Atmosphere,
But some of what Ward proposes seems fairly sensible. Take the early Triassic, for instance, and the astounding change in animal life that took place back then. Before the end-Permian extinction, the therapsids — once called “mammal-like reptiles,” but called that no longer since they were neither — dominated the land, with gorgonopsians as perhaps the top predator in the late Permian. Then whatever it was that caused the end-Permian extinction happened — three guesses what Ward suggests it was — and the gorgonopsians died out along with 95 percent of all the species on the planet, and with conditions pretty damn bleak for those who survived.
Atmospheric oxygen levels in the early Triassic were as low as they’d been since the invention of photosynthesis, Ward says, and the Triassic air at sea level might have offered as much oxygen as modern-day air at 11,000 feet. You and I can survive indefinitely at 11,000 feet: it just takes acclimation, a bit more lethargy relative to life at sea level, and if we’re lucky, coca leaf tea. But our lungs are much better at wresting oxygen from the atmosphere than were the standard-model surviving Triassic therapsids. It’s likely that therapsids spent much of their time breathing hard, eking out a living as herbivores and ambush predators in habitable pockets along the Triassic coasts. Elevations higher than about 3,000 feet would likely have been unpopulated, even by plants, which need sufficient oxygen to diffuse into the soil to keep root cells alive. This low-oxygen climate lasted for tens of millions of years.
And then the first dinosaurs showed up, and ruled the earth. Their lungs were likely far more efficient than the therapsids’. Their present-day descendants, the birds, can fly at altitudes far higher than those humans can reach without canned air. They could get enough O2 from the Triassic air, Ward suggests, that they could hunt cursorially — by running, like wolves and cheetahs, instead of by laying in wait to ambush like moray eels. Not only could they outrun their prey, they could run around all day looking for it. This gave them a huge advantage.
Part of this, Ward suggests, was due to those highly efficient, innovative lungs, which allow them still to dominate the earth to this day: with 10,000 known species, their bird descendants make up the most diverse group of terrestrial vertebrates.
But another part of the reason for the dinos’ advantage, offers Ward, was their good posture. The first dinosaurs were bipeds.
Horses are excellent runners indeed, for quadrupeds. They’ve evolved strong and sturdy streamlined legs, shock-absorbing and tough hooves, pretty flowing manes, the whole gamut. Here’s a famous set of photos of a horse running quite fast, taken by Eadweard Muybridge, collated into animated gif form. Enjoy it for a moment — it’s an important document in the history of visual representation of scientific information — and then we’ll continue.
OK. Now if you will, please watch the horse’s thoracic area for a bit. You’ve got the scapulae and associated muscles working to bring the forelegs forward and then to use them as levers against the earth for forward motion. You’ve got the hips and gluteal muscles doing the same thing in the posterior part of the horse with its rear legs. But there’s something else going on between those two ends. The horse’s trunk is extending, when the legs are at their furthest extension either front or back (which characterizes a gallop) and contracting when all four legs are tucked beneath the horse and off the ground.
It’s a good way to increase power to the legs. There’s just one problem with it. Another bodily function depends on extension and contraction of the trunk: breathing. Unless the rhythms of breathing and running are meshed, at least one of those functions is going to be performed at less than peak efficiency.
For sprints, that doesn’t matter, and horses cover a mile just fine at a gallop, and they can breathe hard later and catch up. It’s a great strategy for escaping predators. But if you need to run for very long distances at a somewhat more moderate pace, doesn’t it make sense to decouple the breathing motion from the locomotion?
I run using my gluteals and hips and legs, and I breathe by expanding and contracting thoracic muscles and ribs, and the two actions are related but not chained together. I can give breaths and paces strict one-to-one parity if I wish, and I do some nights when the jaguar eyes me a bit more intently than usual, but that’s not necessary or even usually advisable. I can run through the usual measured, distracting breathing routine I followed today. I can match my respiration rate to the music in my head.
Or I can let my autonomic nervous system take over and disengage breathing from pace entirely, using a complex and mysterious algorithm based on blood CO2 levels, engaging in a millions-of-years-old family tradition and a signal human talent, a trick we share with the oldest dinosaurs.
Which also frees my mind for the detached contemplation of jaguars. As long as you run toward the jaguars instead of from them, the advantage is yours.
Posted by: Chris Clarke
Note: A database glitch in 2008 ate a bunch of archived comments. Don't be offended if yours isn't here, or confused if the conversation seems disjointed. Thanks!
To be taken with grain of salt:
Shin splints - I never had them again once I started stretching the relevant muscles. Best done in bare or socked feet. Standing, move one leg back, and rest top of that foot on ground. Push that leg forward, stretching the muscles connected to the shin.
Breathing - do you breathe to your midsection rather than chest? I gather players of wind instruments are trained to do this. More air, dontcha know. Took me a while to have it feel natural (why do we think “deep breath” means inflate the chest?), but it paid off.
I found the hard exhalation thing to work as well. That, and not stopping for a smoke halfway through the run.
And oh yeah - Frist!
By: By Rob G on 2007 09 27
There was a time when I could run like the wind for a couple of hundred meters and it was fun. But I could not run like the wind for *four* hundred meters. The last 50 meters were like the slow-rolling stop of a car run out of gas. With pain.
A simple matter of oxygen-less-ness. Who knew?
Frist, too.
By: By black dog barking on 2007 09 27
rob, that is the way we were taught to breathe (as kids in india) during yoga - more specifically, pranayama.
it is so natural to me now that i feel a lack of oxygen if i try to breathe in by expanding my chest a few times.
By: By buck on 2007 09 27
Ooh ooh! You have to get your hands on a copy of Bernd Heinrich’s “Why We Run: A Natural History” if you haven’t already.
I ran competetively for a few years (now a while ago), and a lot of the things that we do instinctively while running are explained in this book. Lots of sciency and biological stuff described very beautifully, while chronocling his own training.
He also covers the theory of our ancestors evolving to be long-distance runners - he ties it to our capability for imagination (envisioning the capture of the deer that can only run for short periods helps to keep tracking and not give up when the prey is no longer in sight).
My own breathing rhythm tends to be in-in out, synched with my steps. It starts out more slowly, but I’m usually only conscious of it when I’m really pushing it and need to be aware of my posture/form/breathing.
By: By Loki on 2007 09 27
Ooh ooh! You have to get your hands on a copy of Bernd Heinrich’s “Why We Run: A Natural History” if you haven’t already.
I ran competetively for a few years (now a while ago), and a lot of the things that we do instinctively while running are explained in this book. Lots of sciency and biological stuff described very beautifully, while chronicling his own training.
He also covers the theory of our ancestors evolving to be long-distance runners - he ties it to our capability for imagination (envisioning the capture of the deer that can only run for short periods helps to keep tracking and not give up when the prey is no longer in sight).
My own breathing rhythm tends to be in-in out, synched with my steps. It starts out more slowly, but I’m usually only conscious of it when I’m really pushing it and need to be aware of my posture/form/breathing.
*edited for spelling
By: By Loki on 2007 09 27
But I could not run like the wind for *four* hundred meters. The last 50 meters were like the slow-rolling stop of a car run out of gas. With pain.
Trained humans can maintain maximum efficiency for about about 40-50 seconds before the lactic acid buildup becomes too great. I recall reading an article some years ago where the technique for the top 400 meter runners was to literally not take a breath for the whole race (I guess in the theory that doing anything that was not absolutely necessary was wasteful). As I recall the runners themselves hated the strategy as it was so painful as they approached their limit at the end. But probably only incrementally more pain than they would have in any case. (And I’m not sure the technique is still used today.) This is an interesting article with a lot of detail on what goes into a good 400 meter run, including the sources of energy. the most pronounced cases of lactate acidosis in athletic competition occurred after 400 and 800-meter racing.
By: By JP Stormcrow on 2007 09 27
Wonderful post.
Just walking bipedally is a precarious exercise
- especially while carrying boxes through a throng* of animals.
*only my cat and my dog could manage to constitute a throng, but they do.
By: By Theriomorph on 2007 09 27
the most pronounced cases of lactate acidosis in athletic competition occurred after 400 and 800-meter racing.
Dr Wiki tells me “Lactic acidosis is an underlying process of rigor mortis. Tissue in the muscles of the deceased resort to anaerobic metabolism in the absence of oxygen and significant amounts of lactic acid are released into the muscle tissue.” After a race we’d walk until it no longer hurt to breath and then stretch some to avoid “stiffening up”. I didn’t realize how noir a little track & field could be.
By: By black dog barking on 2007 09 27
Another good Bernd Heinrich book on endurance running (largely autobiographical—he still holds the masters 100 km record) is Racing the Antelope.
The control of respiration during exercise is actually rather mysterious. At rest, there is a classic negative feedback system that controls ventilation rate and depth to 1. regulate the pH of cerebrospinal fluid and 2. regulate the dissolved CO2 concentration (and therefore the pH) of blood. But when you begin muscular exercise, ventilation increases with no change in blood gas values—there is no stimulus to which you could be responding. Instead, it’s thought that the primary motor cortex—the part of the brain that sends the signals to muscles to make them contract—also directly signals the respiratory control centers in the brainstem. This is called “feedforward”—it’s an anticipatory response rather than the usual reactive feedback response. The other thing that’s probably going on is reaction to stimuli from the proprioceptors—sensors that monitor how much muscles are stretched and joints are bent. Supposedly, if you lay somebody down and rapidly move her leg, bending and unbending the knee without the subject actually contracting any muscles, her ventilation rate and depth will increase anyway—though she’s not actually exercising!
And your blood is leaving the lungs nearly saturated already; a small increase in partial pressure won’t help.
Now lizards…
aw, push my comparative-physiology buttons why don’t you.
By: By Sven DiMilo on 2007 09 27
Another good Bernd Heinrich book on endurance running (largely autobiographical—he still holds the masters 100 km record) is Racing the Antelope.
The control of respiration during exercise is actually rather mysterious. At rest, there is a classic negative feedback system that controls ventilation rate and depth to 1. regulate the pH of cerebrospinal fluid and 2. regulate the dissolved CO2 concentration (and therefore the pH) of blood. But when you begin muscular exercise, ventilation increases with no change in blood gas values—there is no stimulus to which you could be responding. Instead, it’s thought that the primary motor cortex—the part of the brain that sends the signals to muscles to make them contract—also directly signals the respiratory control centers in the brainstem. This is called “feedforward”—it’s an anticipatory response rather than the usual reactive feedback response. The other thing that’s probably going on is reaction to stimuli from the proprioceptors—sensors that monitor how much muscles are stretched and joints are bent. Supposedly, if you lay somebody down and rapidly move her leg, bending and unbending the knee without the subject actually contracting any muscles, her ventilation rate and depth will increase anyway—though she’s not actually exercising!
And your blood is leaving the lungs nearly saturated already; a small increase in partial pressure won’t help.
Now lizards…
aw, push my comparative-physiology buttons why don’t you.
By: By Sven DiMilo on 2007 09 27
Was that twice?
Was that twice?
By the way, pronghorn antelopes and canids have excellent endurance with 4 legs; in the case of dogs, the liver apparently moves back & forth like a piston to effect ventilation.
And I’m laughing at the mental picture of somebody actually runnign to “Blue Rondo ala Turk” in his head—12 12 12 123 12 12 12 123…it’s kind of a weird stumbly pause in there (and in any case that tune is not the same without the original Paul Desmond blues interlude).
By: By Sven DiMilo on 2007 09 27
I remember reading somewhere that kangaroos have evolved such that those great leaping bounds act in a way similar to our diaphrams - though, obviously, kangaroos are still able to breathe when not leaping at full tilt.
Just walking bipedally is a precarious exercise.
Our cat would certainly agree. One of the things about adopting a stray is that there’s a constant process of mutual adaptation, and one of the things we’ve been working on is being comfortable while being held (her) and holding her securely so she’s not afraid of falling (me). We’ve gotten to the point where I can even hold her briefly on her back, or lift her up above my head.
But the one thing she will NOT tolerate is being carrying down stairs. There is just something about being held by a two-legged animal falling its way down one step at a time that alarms her beyond all reason, and my suspicion is that it has to do with that precariousness.
My, but it has been a long time since I’ve run (in more than the “I’m late! Aahh!” way). I’m much better at walking!
By: By Rachel Shaw on 2007 09 28
Sven my friend, that is no mere weird stumble but a 9/8 signature, which has more to do with Turkey than just the invocation in Brubeck’s title.
From Pre-Minoan Influences in the Ecstatic Dance And Music of the Alevi of Anatolia, by Nikiforos Metaxas:
The actual mating dance of the crane consists of nine steps and a wide stretching of the wings. The number 9 was proof of the crane’s sacredness to the goddess for the Pelasgians as being three times the three phases of the moon. It is thought that rhythms in 9/8 have their origin in the mimicking of this dance. The prevalence this rhythm in the Alevi Sema, in the ‘Zeybeck’ rhythms of the coastline of Asia Minor, in the dances of the Black Sea region and Thrace, attests to an archaic Cretan and Thraco-Libyan origin.
By: By Chris Clarke on 2007 09 28
By: By Chris Clarke on 2007 09 28
If you’re comparing quadrupeds and bipeds running abilities, it seems remiss not to mention gaits.
Bipeds really only have a choice between different variations on “walk” (left foot, right foot, repeat).
Quadrupeds have several gaits to choose from, and they’re suited for different purposes.
The gallop, a four-beat gait, is great for sprinting, but it’s definitely not what a quadreped would use for covering long distances. Of course it won’t be efficient for oxygen use.
The trot, on the other hand (where the left hind and right front legs move together), or the pace (where pairs of legs on the same side of the body move together) are much more suited for endurance running. They are two-beat gaits and essentially mimic human jogging.
They’re much more stable, more energy efficient, and don’t present the same problems with breathing control that the gallop does.
Any half-way decent endurance horse can keep up a 6-7 mph trot for 25 miles, while carrying probably 15% of its own weight in tack and human.
The gallop is used when the jaguar is right there, among the herd. The trot is chosen when the jaguar is sighted in the distance, watching.
By: By cyborgsuzy on 2007 09 28
Oh, the Turkish delight.
That’s it, I’m going back.
By: By Theriomorph on 2007 09 28
That is an excellent point, cyborgsuzy, and an omission in my post.
But PZ didn’t omit it in the post to which I refer. Slightly condensed:
Human ER speeds fall between 2.3 [meters per second] and 6.5 [meters per second] (for an Olympic class marathoner), with typical speeds for a moderately fit jogger of 3.2-4.2 [meters per second]. In comparison, the trotting speed of a horse is about 3.1 [meters per second], and once they hit 4.4 [meters per second], they break into an anaerobic gallop. Over long distances, the average speed sustained by a horse is about 5.8 [meters per second] — which means that a well-trained, conditioned human being can keep up with or even outrun a horse if the race is sustained long enough.
By: By Chris Clarke on 2007 09 28
Oh, I don’t know that humans are limited to a right-left two-beat alternation. Haven’t you “galloped” as a kid, or sashayed to the right or the left while dancing?
(There’s hopping one-footed, too, but that’s pretty slow, unlike the other two. I could gallop pretty fast as a kid.)
By: By Rachel Shaw on 2007 09 28
In fact, it’s hard to skip as slow as one would normally walk, I find.
By: By Chris Clarke on 2007 09 28
You know, I don’t skip enough any more.
Human walking and running are actually different “gaits” energetically, as the energy cost of running increases linearly with speed, but the energy cost of walking increases curvilinearly with speed (i.e. it’s way more expensive energetically to walk fast than to run slow. Try it.)
And I must say that that’s (link in #16) the first folk dance I have seen that commemorates some dead tobacco-smuggling brothers. How (not to ask why—that music’s fascinatingly exotic) do you find this stuff?
By: By Sven DiMilo on 2007 09 28
It’s a Turkonarcocorrido!
By: By Chris Clarke on 2007 09 28
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