Happy Feet: Tips For Healthier Running

May 23, 2012

Guests: Jeremy Denk – Gretchen Reynolds

TERRY GROSS, HOST: This is FRESH AIR. I'm Terry Gross. My guest, Jeremy Denk, is an acclaimed classical music pianist who also writes a popular blog about music and his life. The New Yorker music critic, Alex Ross, describes Denk as, quote, "a superb musician who writes with arresting sensitivity and wit," unquote.

Denk has performed with many orchestras and chamber groups and since 2004 has frequently performed with violinist Joshua Bell. Denk's new album is called "Ligeti/Beethoven," and it features a Beethoven sonata and a series of etudes composed by Gyorgy Ligeti in the last decade of his life. He died in 2006.

An etude is a composition that's meant to build the pianist's technical skills. In the liner notes, Denk says, quote, "These etudes celebrate the genre's perversity and repurposes it into wild, unheard-of art, drawing inspiration from the etude's most unpromising attributes: obsession, monotony, ad inifinitum at repetition, mathematical dryness. Ligeti fearlessly redeems them," unquote.

Denk describes some of Ligeti's writing as fiendish. You'll hear why in the crashing descending lines that conclude the sixth etude.

(SOUNDBITE OF MUSIC)

GROSS: Jeremy Denk, welcome to FRESH AIR. So that incredible descending climax that we just heard, it sounds so physical to me. It sounds like the force of gravity expressed through music.

JEREMY DENK: That's good.

GROSS: I just feel this pull, you know, and then this thud at the end. It almost reminds me, I don't usually use analogies like this, but when I throw trash down the trash chute, and you hear it kind of falling down, and then it, you know, hits the ground, it's kind of what it - it's like so physical. Can you talk about just the experience of playing that?

DENK: I mean, it's sort of like trickling down the drain of tonality or something like that.

(SOUNDBITE OF LAUGHTER)

DENK: And the idea of the piece, I guess, is something Ligeti was obsessed with late in this life, was this lamenting, descending chromatic idea, you know, and descending chromatic lines like are - have been used in music for centuries to, you know, designate sadness. And so - and there's this way in which that idea just becomes so obsessive and destructive and takes over and becomes - transforms from something beautiful into something sort of horrible and all-consuming. That's the idea, anyway.

(SOUNDBITE OF LAUGHTER)

DENK: It's also very physically difficult, unfortunately, because it's so - he wants ever louder and ever more complicated sounds towards the end, and you're just trying to get this devilish feeling.

GROSS: So technically what is he doing there to make your life difficult?

DENK: What is he doing there? Well, the main thing Ligeti is doing is he's throwing in different chromatic lines all the time in different voices and then, towards the end, of course, amassing a tremendous amount of sound and making you pound out one more devastating chord after another. Especially after the sort of four minutes of the etude as a whole, you know, you're pretty wiped out mentally, and then you have to create this visceral, destructive force.

GROSS: What are these Ligeti etudes that you've just recorded intended to do? Are they intended to be exercises, performance pieces, both?

DENK: Well, they're kind of like explorations of new frontiers, I guess. It's interesting because Ligeti took the piano to places it had never been before and makes demands of the pianist and the mind that had never in a way been made before. But all of it is derived from ideas from earlier piano etudes and his love of the great piano repertoire.

So it's an interesting mix of things. Ligeti was obsessed with chaos theory and fractals, and so part of the etudes is extrapolating these sort of mathematical ideas into music; infinite complexities and things that begin simply and then with one small branching or one little instability suddenly become incredibly complex and wild.

GROSS: So I want to play another excerpt from one of these etudes, and this is from "Vertige," which means vertiginous, dizzy.

DENK: Uh-huh, yeah, this is another chromatic nightmare, just like - yeah.

GROSS: You call this one the most fiendish of them all.

DENK: Yes.

GROSS: Why?

DENK: Well, what he's done is pretty despicable at the beginning.

(SOUNDBITE OF LAUGHTER)

DENK: He writes a set of - any pianist will tell you. He writes a set of chromatic scales, you know, very fast, and he writes over them legato. And he also writes - so you have to play them super-connected, right, so there's no spaces between the notes. And then he keeps adding different chromatic scales at different time intervals.

So you end up playing like - it's like a million exercises in one thing, you know, like every kind of thirds, fourths, all kind of intervals. Like every little finger-twister you can think of happens in the first page. And then it's all supposed to be incredibly soft, connected, and then he writes - the real mean thing is he writes no pedal, which is like kind of this - you know, you can't even rely on the usual pianist's crutch for doing these sorts of things.

GROSS: In what sense is the pedal a crutch?

DENK: Well, the pedal connects - the pedal allows the string to resound. So when you are unable to connect some complicated set of notes to the next because your fingers are like - it's like playing Twister with your fingers, sort of. So at that moment when you've got the stumping, the chord that you can't quite reach, you put down the pedal for a millisecond, and it will connect what you can't connect with your fingers.

It may be that I relied every so often on a little, hidden pedal in this opening passage to help, even though Ligeti told me not to.

GROSS: So I think what I'd like to do is play that opening passage and then kind of skip ahead a little bit to some of the more bass clef madness that sets in afterwards. So let's hear the very opening.

DENK: Great.

(SOUNDBITE OF SONG, "VERTIGE")

GROSS: So that's the opening that you were describing. I'm going to skip ahead a little bit. We're continuing to hear those trebly notes, but they're starting to get louder, and then the left hand starts in and starts rumbling away in opposition. Can you tell us what's going on in that passage?

DENK: Well, that's a wonderful moment, and I guess, you know, Ligeti's written this series of kind of overlapping chromatic scales coming down. And while the scales are coming down, the pianist is creeping ever farther up into the stratosphere of the instrument, right, and you have this great sense of sort of falling and rising at the same time.

And, right? And then as it gets softer and softer, hopefully, and then you get to the very top of the keyboard, and at that moment the bass comes in. And that's such a classic Ligeti thing to go from the very highest register to the very lowest, to kind of span the mind gap between the top and the bottom of the keyboard.

It's a very Beethoven thing, too, actually, to explore these registral extremes, but it's very wicked sounding and very disturbing when the bass comes in.

GROSS: It is disturbing. It's very invasive.

(SOUNDBITE OF LAUGHTER)

DENK: Yes, it is, and very difficult, also. He writes some very nasty things there for the pianist to do.

GROSS: OK, so this is Jeremy Denk from his new album "Ligeti/Beethoven," and here's more from the Ligeti etude "Vertige."

(SOUNDBITE OF SONG, "VERTIGE")

GROSS: That's Jeremy Denk from his new recording of Ligeti etudes and a Beethoven sonata. So how obsessive do you need to be in order to learn a piece like we just heard?

(SOUNDBITE OF LAUGHTER)

DENK: Well, I'll tell you, there was a period, I don't know if it was a fun period or a miserable period, and last - maybe a year and a half ago where I was sitting in my apartment for four weeks. I was brewing two pots of coffee a day, and I was practicing maybe seven hours, you know, with a little break in the middle for a walk or some sort of entertainment.

But I did nothing else and put in - I mean, the amount of fingering, the amount of sort of mental focus, you know, and there's - Ligeti's deliberately written things that are going to screw with your mind in one way or another. And you have to develop new muscles, new kind of mental muscles, 'cause he's really fascinated with, you know, simultaneous different rhythmic groupings going on. So in a way, you have to divide your body and mind in two parts.

GROSS: I'm just trying to think about what the sheet music must look like for this. You know, I'm one of the many people that played piano or got piano lessons in elementary school and junior high and then gave it up and so on. So I have like a child's understanding of, like, sheet music. And you show me something really complicated, like this would look, and I would just have no idea what any of it meant, even though I can read simple music, because it gets so complicated.

I mean, how do you even figure out what the meter - you know, what - how much of a beat each note gets when things are so fast, and there's so many notes crowded into each measure? Does that sound like an incredibly stupid thing to ask? I'm sorry, But I really do have like a child's understanding of all of this.

DENK: It's not a stupid thing to ask and actually because it happened that I was following along with the score when we were editing together the record. And I often had trouble finding myself on the musical score, where I was. So somehow I was able to play it, but I wasn't able to follow the music at the same time, if that makes any sense.

The scores do tend to look, some of them especially, look a little like undifferentiated, like, streams of data, you know, like you'd imagine a programming code would look. And it takes a little bit of practice to, you know, pick out the important one. It's sort of like reading the matrix or something from - you know, you have to know what he's after.

And then once you kind of discover the principle behind the etude, the musical score will look a little more commonsensical, but it takes a little while, especially, for example, the first one, "Desordre," where he splits the sort of bar line between the left and right hand, it begins to split like there was a seismic shift, and it was like a crack splitting between the two bar lines.

And then you have to make all sorts of decisions of how you're going to think of the rhythm because Ligeti was obsessed with, like, not really writing in bars or meters but the constantly shifting sense of what the meter is, you know, the pulse. Not the pulse, the pulse is fixed, but the meter is shifting.

GROSS: If you're just joining us, my guest is pianist Jeremy Denk. He has a new recording of music by Ligeti and Beethoven. Let's take a short break here, then we'll talk some more. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

GROSS: If you're just joining us, my guest is pianist Jeremy Denk. He has a new album of music by Ligeti and Beethoven. So, we've heard some of the Ligeti that you play. Let's hear some of the Beethoven. Let me start by asking you why you've grouped these two composers together. What commonality do you find in them?

DENK: There's a lot of different commonalities. One thing is that late Beethoven was so insane in many ways that those - some elements of the last pieces, the whole 19th century couldn't really deal with. And I think only in the mid-20th century do people begin to sort of take up the weird mania of late Beethoven and use it for further explorations.

And I think in some ways the Ligeti etudes can sound like sequels to some of the weirdest moments in late Beethoven, and Ligeti is really obsessed, as I said, with like chaos theory and fractals and these things that are infinitely complex. And almost every one of the etudes is kind of like a little visit to infinity of one kind or another.

And the last Beethoven sonata seems to me one of the most profound sort of musical journeys to infinity ever made. The whole piece seems to want to bring us from sort of a present moment into this timeless space where everything is continuous and endless. So that's kind of the connection between Beethoven's sort of vast infinity and Ligeti's bite-sized bits of infinity.

GROSS: And on a more prosaic level, I think a comparison is that both the Ligeti that we've heard and the Beethoven we're about to hear seem very obsessive about, you know, repeating a certain theme or a pattern in a very tumultuous and demanding way.

DENK: Yeah, Beethoven obsesses about this three-note idea in the first movement, and it becomes kind of a - what they call kind of a fixed obsession, like fixed (unintelligible).

GROSS: An idee fixe?

DENK: Idee fixe, yeah, yeah. And he's so interested in his last works in sort of concision and how much can be said and how little. So this whole first movement is just on those three notes.

GROSS: So let's hear an excerpt of that first movement.

(SOUNDBITE OF MUSIC, "SONATA NO. 2 IN C MINOR, OP. 111")

GROSS: So that's my guest Jeremy Denk playing an excerpt of Beethoven's Sonata No. 2 in C Minor, Opus 111 from his new album of music by Ligeti and Beethoven. I have to say listening to that reminds me really of mind on a very bad day, where, you know, like you're just totally obsessed with something, and it won't stop, and just as you think it stops, it's like back again.

DENK: That's true.

(SOUNDBITE OF MUSIC)

GROSS: But it's really just so commanding. You have such an incredible commanding presence at the piano. And no matter how fast and tumultuous the playing is, I feel like every note is so crisp, so delineated, so, like, clearly delineated.

DENK: Oh, that's nice. That's - I hope so. Yeah, that's - in this movement especially, there's a sense that, you know, you really want to pound out the idea with kind of steely fingers. You know, you really want to hear each note as it kind of obsessively climbs in these kind of fugal passages. So I guess I was aiming for that element, yeah, the clarity but also the sort of drive behind the notes.

GROSS: You recently wrote a piece in The New Yorker about the difference - about recording and how if you're a classical musician now, and you're making a record, you're not doing it to make money because the odds are against you. You are probably not going to make any money, but you'll be able to sell it at concerts.

And you talk about how difficult it is to record a piano and record it well. What are some of the problems of recording a piano as opposed to other instruments?

DENK: I was kind of under-educated about, you know, the real, like, nuances of mic placement, but the piano is always decaying, right, so that you always have the beginning of the note, and you have the attack, and then you have this sort of ephemeral singing remainder that comes off of it.

And the balance between those two elements is really delicate. And depending on where you put the mics, the piano can sound completely different, right, and you can capture more bass or more treble. So it's like this really chameleonic situation. And that's a whole other, like, layer of relativism in making a record that's amazing. You're like this is the way I play this piece, but then depending on where he puts the mics, you know, your piece sounds completely different.

In fact in doing the Ligeti, the fourth etude, we changed something, put a little veil between the mics and the piano to be able to create a more veiled sound in that etude. It's like something even more nuanced than being in a concert hall.

GROSS: How willing are you to use digital technology to fix things, to change the length of a pause, to change the beat of something, to edit in different parts of different performances to make a complete performance?

DENK: I'm disturbingly willing to do these things.

(SOUNDBITE OF LAUGHTER)

DENK: But up to a point. And Adam, my producer, is - you know, always the best thing is to have it just as it is, you know, some great take. And occasionally you feel you really must monkey with a little bit of timing or something that wasn't quite exactly right or something. But the best thing is to have the take there and just put it out.

And a lot of the 111's second movement, for example, is in one continuous take because of the nature of the music. You want it to speak naturally, as you would when you were playing. But sometimes it can be fun when you want to bring out - you know, there are certain times that I forgot to bring out one voice or another, and you're able to voice up one note or another in some of these Ligeti etudes, for example, to reveal some dirty laundry.

(SOUNDBITE OF LAUGHTER)

DENK: So, you know, it can be fun in a little way.

GROSS: Well, Jeremy Denk, thank you so much for talking with us.

DENK: Thanks, my pleasure.

GROSS: Jeremy Denk's new album is called "Ligeti/Beethoven." Denk writes a popular blog about music and his life. You'll find links to some of his funniest blog posts on our website, freshair.npr.org. I'm Terry Gross, and this is FRESH AIR.

TERRY GROSS, HOST: This is FRESH AIR. I'm Terry Gross. The classical music world lost one of its legendary figures last week. The German baritone Dietrich Fischer-Dieskau died just short of his 87th birthday. Classical music critic Lloyd Schwartz is one of his admirers. Here's Lloyd's tribute.

LLOYD SCHWARTZ, BYLINE: Dietrich Fischer-Dieskau had almost too much going for him. His voice was almost too beautiful, and once he lost his baby fat, he was almost too good-looking. And he was almost too versatile. He sang opera and oratorio, Bach, Mozart and Verdi, as well as modern and contemporary works. He was a great Wozzeck in Berg's bleak, expressionist opera. Benjamin Britten composed the baritone role of his famous "War Requiem" for Fischer-Dieskau, who sang the world premiere under the composer's direction at the reopening in 1962 of the bombed-out Coventry Cathedral in England, and on the very first recording.

He was probably most admired for his vast repertoire of art songs, which he sang in his native German, as well as in English, French, Russian, Hungarian and even Hebrew. He was surely the 20th-century's most famous interpreter of German lieder: Schubert and Schumann, Brahms and Mahler.

Here he is bringing a remarkable freshness to the second song of Mahler's "Songs of a Wayfarer," "I Went Out This Morning across the Field." Isn't it a beautiful world, the singer asks. Sadly, without his love, he can't correspond to the joy he sees in the birds, the flowers and the sunshine. But it's the joyful opening that's most captivating.

(SOUNDBITE OF SONG, "I WENT OUT THIS MORNING ACROSS THE FIELD")

DIETRICH FISCHER-DIESKAN: (Singing in German)

SCHWARTZ: I heard Fischer-Dieskau live only a few times. Once was at Carnegie Hall in a concert performance with one of his dearest collaborators, soprano Elisabeth Schwarzkopf, and once at Boston's Symphony Hall, in a seldom-performed, but deeply moving early Brahms song cycle, "Die Schoene Magalone." He didn't have a huge voice, but he sang with such point and focus, you could hear every nuance from the back row.

Fischer-Dieskau was an extremely intelligent artist. When he wasn't singing, he was coaching or teaching, or writing books on music. I loved the collections of song lyrics he put together and his sensitive commentaries. Later, he also added conducting to his career.

Here is one of his great performances of Schubert. It's the last song of the tragic "Winterreise" cycle, "Winter's Journey." The accompanist is pianist Alfred Brendel. After traversing a desolate landscape, as psychological as is it literal, the singer's final vision is of an old organ-grinder singing out in the cold: frozen, despised, even by snarling dogs. His collection plate is empty. The mysterious hurdy-gurdy man carrying out his calling, even in the bitterest chill of winter is an image of the suffering artist. Fischer-Dieskau sings this with a sense of understated, but heartbreaking identification and awe. It's an awe his audiences have felt ever since his career started midway through the last century.

(SOUNDBITE OF SONG, "WINTER'S JOURNEY")

FISCHER-DIESKAN: (Singing in German)

GROSS: Lloyd Schwartz is classical music editor of the Boston Phoenix, and teaches creative writing in the MFA program at the University of Massachusetts, Boston. Dietrich Fischer-Dieskau died last Friday.

Coming up, some tips on running shoes, some bad news about high heels, and when not to take ibuprofen. Part two of our interview with Gretchen Reynolds, who writes The New York Times "Phys Ed" column, and has a new book about exercise. This is FRESH AIR.

TERRY GROSS, HOST: Whether you're jogging or just walking around the office in high heels, you've got to watch out for your feet and your legs. We're going to hear Part Two of our interview with Gretchen Reynolds, who writes the "Phys Ed" column for the New York Times blog Well. She also has a new book about the latest research about exercise. It's called "The First 20 Minutes." Reynolds is an avid runner and in Part One of our interview, she explained that although running, when done right, can be good for you, most runners will eventually have to deal with a running-related injury.

What injuries have you had as a runner?

GRETCHEN REYNOLDS: Well recently, I hurt my iliotibial band, which runs along the outside of the knee. And I also hurt my Achilles tendon, which I had never done before. And I did that, I must admit, when I tried barefoot running.

GROSS: Mm. Why did you try that?

REYNOLDS: I tried it because everyone was talking about it. And there was very little science about whether it was a good idea or a bad idea. It's certainly a very popular idea, and a lot of people are now trying barefoot running without preparation, without knowledge of what happens when you take off your running shoes. And I was one. And what often happens is exactly what happened to me - which is that you almost immediately hurt your Achilles tendon.

GROSS: Is that because of the pressure, or the position of the foot?

REYNOLDS: Well, it's because - many people have heard that we are born to run, and that may or may not be anthropologically accurate. But we definitely have been brought up to wear shoes, and your body adjusts to what it is used to. So every muscle in your leg, every tendon, every ligament is used to how you land with shoes on. If you've been doing that for 40 years - which many of us have, if we're 40 - then your body is very used to that movement - to how you hit the ground with shoes on. The forces of the - of hitting the ground move up your leg in a very specific way.

You take off your shoes and even if, in theory, it's healthier, you're not used to it. And most of us who try barefoot running - and this is quite common - take off our shoes and do the same amount of running as we did with shoes on. The result is, our legs are not ready for it. The tissues, the tendons are not ready; and injuries are very common.

GROSS: Have you recovered yet?

REYNOLDS: Not completely. But I have returned to wearing shoes.

GROSS: So are you running again yet?

REYNOLDS: I am. And I'm running slowly. I'm running carefully. I'm running a little smarter, and that's certainly something that all runners need to be aware of - is, if you hurt yourself, you then have to be a little smarter. The single biggest risk factor for a running injury is a prior running injury. So if you've hurt yourself in the past, you probably need to change a little bit about how you run. You may need to warm up a little more. Some people like to switch to trails. There's not actually much science showing that the surface matters, but it definitely matters how many miles you do. And I'm running a fewer miles now, than I was.

GROSS: Now, what about the pros and cons of running when it comes to hips and knees?

REYNOLDS: Well, the science is very encouraging - in terms of both, as a matter of fact. There's a very strong myth that running will ruin your knees. And anyone who has run for as many years as I have has had people say to them, you're going to ruin your knees. Well that, scientifically, is just not true. The science actually shows that if you have a healthy knee to start with, running tends to increase the amount of cartilage that you produce. It prompts the cartilage cells - which are the shock absorbers in your knee - it prompts them to divide and produce more cartilage. So in theory, running is actually healthy for your knees.

There have been some very good studies showing that people with healthy knees, who run for decades, have no greater incidence of arthritis than people who don't run. The problem comes in if you've ever had a knee injury - and especially if you've ever torn your ACL, the little ligament that helps stabilize the knee. And ACL tears are very, very common. They're very common among young athletes nowadays. And what appears to happen is if you've ever torn your ACL, your knee is unstable. When you run, you start rubbing one part of the knee against another. You rub away cartilage. And so if you've had a prior injury and run, you can develop knee osteoarthritis very quickly; certainly, within a decade.

The same - very same process appears to happen in the hip. The hip is really important to running, and many people ignore it. It starts to hurt; they ignore it, and keep running. Again, if you have an unstable knee joint and run on it, you will probably cause arthritis. If your knee is healthy and you run on it, it will be good for the knee. It's a rather unfortunate catch-22.

GROSS: Let's talk a little bit about running shoes - and walking shoes, too. Some of the common wisdom about running shoes, apparently, is being disproven.

REYNOLDS: Yes. As in so many things, when they are actually put to the test in a laboratory, many of our beliefs about running shoes are being overturned. Many of us have been told we pronate a lot - that means our foot turns in - and that we need to stop that. There was a vogue for motion-control shoes, which are fairly heavy running shoes with all these features that control how your foot moves and essentially, tried to keep it from moving. The science is now suggesting that that doesn't help, and probably hurts. There are some very good studies showing that people who wear heavy motion-control shoes tend to get injured more often than people who wear any other type of shoe. It doesn't matter if they do pronate, or if they don't pronate. They get injured more if they wear a heavy running shoe.

GROSS: Is that because of the weight, or because of the control? Or both?

REYNOLDS: Almost certainly - it's not completely clear yet, but it almost certainly is because it keeps your foot from moving the way it actually should. Our foot is a beautiful instrument. It's got all of these bones and tissues that are designed to move and stabilize our body. When you encase it in this big, heavy brick of a shoe, what you do is, you take away all of the ability of the foot to stabilize your body.

That's why many people believe barefoot running is great for you. And for some people, it may be really good. It does allow the foot to completely control how your body is stabilized against the ground. For many of us, a much more lightweight shoe, something that protects our foot from the ground, that gives us a little bit of cushioning - whether we walk or run - does seem to be the best compromise between these really heavy, motion-control running shoes and going barefoot.

I now am starting to run in a - sort of a racing flat shoe, which is very light but it gives me a little bit of support; and definitely, my Achilles tendon doesn't hurt as much.

GROSS: So does this have any implications for orthotics?

REYNOLDS: The science on orthotics is very mixed, which is quite interesting. There's another, very entrenched myth that orthotics will keep people from getting injured; that if you go and see someone and they fit you with a customized orthotic, that you can run or walk or do any sort of exercise, and you'll never hurt yourself.

GROSS: And you'll never develop plantar fasciitis. That's another thing.

REYNOLDS: Exactly. Well, it's just not true. When they actually put people in custom orthotics or over-the-counter orthotics or nothing, there's very little difference in the injury rates. There seems to be a pretty strong placebo effect. People who get custom-made orthotics think that they're going to get less injured. Perhaps that will keep some of them from getting injured. But there's not very good science that orthotics will actually protect you from something like plantar fasciitis, whereas that is one instance where stretching almost certainly will help. Plantar fasciitis is caused by shortening of the tendon that runs under your foot and up your leg. And that, you probably need to stretch, especially as we get older.

GROSS: So in talking about shoes and orthotics, we should talk about high heels. You had a column about that recently. And what are some of the things that you learned about the stresses put on the foot, and the leg, from high heels?

REYNOLDS: Well, high heels are essentially a very exaggerated version of shoes. Most of us wear shoes - if we don't wear heels - that have some heel, but not a lot of heel. Even wearing shoes with a small amount of heel, it does affect the tissues in your leg. If you increase that heel, you exaggerate those effects.

What you start getting is a pretty significant shortening of the Achilles tendon. You get changes in all the tissues that run through your foot. You get changes in how your foot is oriented to the ground. If you wear high heels for five or six hours a day - and I don't know how anyone does, but they do - you pretty dramatically change how your foot is oriented.

And then, when you take high heels off, your foot is not ready for that. It honestly does not know how, essentially, to come into contact with the ground. Women who wear high heels all the time and then walk without them, walk completely differently than women who do not wear heels. And they probably increase their risk of a whole host of injuries.

GROSS: What's the difference between how women who frequently wear high heels walk, compared to those who don't?

REYNOLDS: Well, women who frequently wear high heels - again, the Achilles tendon shortens, and that changes how forces move up your leg. Your foot moves differently with each stride that you take. You can't move the forces as efficiently up your leg, so you get more forces moving up through the tendons than you would if you did not wear high heels.

If you don't wear high heels, your foot impacts the ground in a way that makes the forces move up through the bones, which are much better able to handle those forces. So if you wear high heels and then you walk without them, you get more forces moving up through the very soft tissues in your leg, and that definitely increases the chance of injury.

GROSS: You know, I sometimes ask somebody - ask a woman, like, gosh, how do you wear high heels like that? And they'll say to me, well, I'm actually more comfortable wearing heels than wearing flats. And from what you're saying, it sounds like it's because their foot is so trained to wearing heels, that it's difficult for the foot to adjust to contact with the ground.

REYNOLDS: Yes. That's definitely true. It actually is uncomfortable. Because you have a shortened tendon, it will feel tighter when you walk barefoot, or even in flats, if you are used to wearing high heels. So if you have been wearing high heels for years and years and decide that you want to go to flats, then you need - as with someone switching to barefoot running - you need to do it gradually.

You need to retrain the tissues in your leg to walk differently. And it will take some time. But it will definitely, ultimately be healthier for your leg.

GROSS: So let's talk about dealing with muscle soreness, the kind of soreness that can set in with overexertion or with, you know, a rigorous workout routine.

I was surprised to read in your book that taking a non-steroidal anti-inflammatory - you know, ibuprofen, something like that - can help you with the pain in the short term, but it's not necessarily going to help you with healing and, in fact, it might be counterproductive.

REYNOLDS: That actually surprised me. I hang around with a lot of athletes, and there are many athletes who take that non-steroidal ibuprofen every day. They take it before they work out because they hope that it will have a prophylactic effect; that it will keep them from getting sore after they work out.

And many professional athletes take three, four of these ibuprofen pills before every match, before every workout. The science actually shows that ibuprofen blunts the training response. It actually makes it harder for your muscles to adjust after exercise. So you actually get a little less muscle healing, and you get less muscle adaptation.

So if you take ibuprofen to try and keep yourself from getting sore, what you are doing is - probably, ultimately - increasing the chances you will get sore because your muscles are not as strong, not as well-adapted.

GROSS: Now, this doesn't apply to, say, the effects of ibuprofen in bruising.

REYNOLDS: No. Ibuprofen - what ibuprofen does really well is if you have actually hurt yourself - say, you sprained your ankle; you actually fell over and, as you said, bruised something - it will decrease swelling, and it will decrease pain. If you have an acute injury then, yes, that's probably what it's good for. If you are taking it to try and combat sore muscles, it's almost certainly a bad idea.

GROSS: So if the research says that ibuprofen isn't necessarily going to be helpful, it might be harmful in helping with sore muscles after a workout, what about icing? A lot of people like to ice after exercise.

REYNOLDS: There's quite a bit of research that suggests that it does not, in any way, speed the healing of muscles. It does make them feel a little better, and that can have both good and bad effects. If your muscle feels better and you've just had a hard workout, you may say huh, I can work out hard again tomorrow. That will not be effective. The most effective way to recover from a hard workout is to get a little bit of rest.

That actually allows the muscles to heal themselves, to adapt, to become stronger, to be ready for another workout - maybe the day after tomorrow. If you want to use ice, bear in mind, you still need to rest that muscle even if it feels a lot better.

GROSS: What do you do for muscle and nerve pain?

(SOUNDBITE OF LAUGHTER)

REYNOLDS: Not work out very hard. I actually do not run, certainly, as hard as I did when I was in my 30s. And one, very easy way to avoid having to recover a lot is not to work out super hard. If you do, in fact, work out hard enough to be sore, the best thing you can do is plan to either take the next day off or certainly, go easy.

There's very mixed research about whether massage works. I love massage, so I will continue to get massages whether they actually speed healing or not. And there's some evidence they might; there's some evidence they might not. If you like them, can afford them, by all means get a massage.

GROSS: Gretchen Reynolds writes the "Phys Ed" column for the New York Times blog Well. Her new book, about the latest research on exercise, is called "The First 20 Minutes." You can read an excerpt on our website, freshair.npr.org, where you can also download podcasts of our show. And you can follow us on Twitter @nprfreshair, and on Tumblr at nprfreshair.tumblr.com.

Transcripts are created on a rush deadline, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of Fresh Air interviews and reviews are the audio recordings of each segment.