IRA FLATOW: This is Science Friday. I’m Ira Flatow. After a long winter cooped up indoors, there is no better feeling for runners than lacing up and hitting the road come spring. It feels invigorating until hours later when they’re back home and have legs feeling like jello and then comes the burning sensation. Is that you? 

Do you then reach for some ibuprofen known as vitamin I to the running community? You wash it out with a big glass of water to make sure you stay hydrated? You grab some ice from the freezer to beat back the inflammation you’re starting to feel in your knees and your hips. And later, you won’t forget to do 30 minutes of stretching on that foam roller, right, so you won’t be sore tomorrow when you hit the road again. 

It’s a recovery regime that’s familiar to even a casual runner, because it sounds so much like common sense. You fight pain, you hydrate, you stretch, ice your muscles, but according to science journalist Christie Aschwanden following the seemingly logical steps for a faster recovery achieves just the opposite. Icing your muscles slows down the recovery process, too much water can be harmful, and stretching, you can put that in the same category as compression boots and cupping. They don’t help recover one bit, according to my next guest. 

And here’s a question to my listeners. Do you have a workout recovery method that you swear by? Give us a call 844-724-8255, 844-sci-talk, or tweet us @scifri. We’ll run it by Christie Aschwanden, who is a science writer and author of Good to Go on the science of recovery. And we have an excerpt at sciencefriday.com/recovery. Welcome to Science Friday. I’ve been so looking forward to talking to you. 

CHRISTIE ASCHWANDEN: Oh, thank you so much for having me. Please to be here. 

IRA FLATOW: Did you have an epiphany moment at some point in your career that you said I’m going to take on all this common knowledge about recovery? 

CHRISTIE ASCHWANDEN: It’s funny I didn’t have a moment where I was doing one of these ridiculous things, but I did have a moment where I realized that I haven’t really managed to get recovery right, and recovery’s something that has gotten more and more attention not just from athletes but also by marketers in recent years. And I noticed that this stuff was just everywhere, and I was being bombarded with press releases about new products that were supposed to be helping recovery. 

And yeah, I’m a former elite athlete myself. And when I look back on my athletic career, I can see that recovery was, sort of, the thing that I never managed to master. And so I really set out thinking that some of this stuff was going to be helpful and wanting to, kind of, see what was good and what wasn’t. 

IRA FLATOW: But I think probably the biggest myth that you tackle in the book is that icing is good for recovery, because we see so many athletes doing that right after intensive athletic achievement. Why is icing the wrong thing? 

CHRISTIE ASCHWANDEN: Yeah, so this is something that if you kind of think about the basic science here, and I guess I would throw this back to you, Ira, and say what are you expecting to get out of icing? What are you thinking that you’re doing when you’re putting that bag of ice on your muscles? 

IRA FLATOW: I’m doing what somebody told me to do. 

CHRISTIE ASCHWANDEN: Right. Right. OK, but the thing that people are told and the idea here is that you’re stopping inflammation or that you’re slowing inflammation. And the basic concept here is that inflammation is part of your body’s healing process. And so it’s actually not something that you want to stop or slow. I mean, that’s actually where you’re going to get better. And if you want to get less sore, you have to let your body actually make those repairs and bring in this inflammatory response to make repairs that you’ve created through damaging exercise 

IRA FLATOW: I guess people and you mention this in your book that the icing may make the pain go away, but it doesn’t help the healing. 

CHRISTIE ASCHWANDEN: Right. So icing is a very good, sort of, painkiller. So anyone who’s ever done an ice bath or put ice on something knows that initially it sort of hurts like hell and then eventually you get numb, and then that feels good and that could really take the pain away. And there are situations where that might still be appropriate. I don’t want to just throw everything out in one fell swoop. 

But if you are icing in hopes of becoming less sore or if you’re in the middle of say a training session, we often see this particularly with professional athletes like NBA players or football players where they’re in a training camp preseason and they’re all getting into these big dumpsters full of ice water afterwards, and this is exactly the wrong thing. This is not what you want to be doing then. 

Because if you’ve been doing some hard exercise in hopes of getting fitter, faster, stronger, you actually want that inflammation process to come in and do its magic. That’s the process by which you’re going to get better and your muscles will get stronger. So you don’t want to slow down inflammation. 

But the other issue here is that icing really just slows down this process. So when you ice your extremities, your body sort of pulls all of the blood into your core. And so you’re reducing the blood flow to those areas but only temporarily. So once the ice goes away, you heat up again, the blood flow continues. So it’s really a temporary process to use. So the idea that this is going to have profound effects in a beneficial way is just sort of misguided. 

IRA FLATOW: And you said that you don’t stretch anymore. That if you’re running partner wants to, you will do that. But otherwise, you don’t bother. I thought stretching was like I thought icing. 

CHRISTIE ASCHWANDEN: Right. Right. Well, I’ll just tell you in high school I was the team captain of our track team, and before practice every day we had about a 15 minute ritual where we had a very– it was very ritualized– all of these stretches that we would do. And we really thought that we were doing something good. Our coach told us that this was going to make us less sore. There’s also an idea that stretching might reduce the risk of an injury, but it turns out that those ideas aren’t supported by the science. 

And in fact, there have been some pretty good very large scale studies looking at stretching. Some of these were with people in the military where you have very large groups of people and they could really control what they were doing. And it turns out that stretching doesn’t prevent injury, and it doesn’t reduce soreness either. Now the one caveat I would put there is that if you are doing a stretch that say your physical therapist prescribed for you for an existing injury, then that may be a different situation. But just stretching in hopes of reducing soreness is– you can forget that. 

IRA FLATOW: Let me go to a tweet, then I’ll go to the phones, because we have lots of calls. June tweets drinking water is my recovery method, and boy do you say that’s a no, no. You don’t need to drink water. 

CHRISTIE ASCHWANDEN: Yeah, so I do not say that you don’t need to drink water. But the point here– I have an entire chapter in the book about hydration, and the point is that we’ve really turned hydration into something far more complicated than it needs to be. So there’s this advice that’s given now that you need to drink early and often and that by the time you’re thirsty, it’s too late, and this is just nonsense. 

It’s not– our bodies are very well adapted to be able to deal with some fluid loss, particularly during exercise. It’s OK to sweat. You don’t have to replace every drop of sweat right away. It’s perfectly fine to listen to your thirst signals. And in fact, that’s the ideal way. That’s what our bodies were meant to do. 

And what we’ve done now with this advice and this focus on hydration and people always worrying about making sure they’re hydrated is that we actually have people who are dying now from taking in too much water during exercise and too much fluid. I mean, we have– while I was working on the book I tried very hard to find a documented case of someone who had died of dehydration during a marathon or some other sporting event like that, and I didn’t find a single case. What I did find was at least five people who have died from hyponatremia, which is basically over-hydration that they acquired during a marathon. 

IRA FLATOW: Wow. Talking with Christie Aschwanden, author of the new book, Good to Go, what the athlete in all of us can learn from the strange science of recovery, which is out now. And let’s recover and go to Berkeley. Audrey, welcome to Science Friday. 

AUDREY: Hello, thanks for taking my question. So I was wondering if there’s a consensus about whether like soaking with Epsom salts is helpful for recovering and for like relieving soreness. 

CHRISTIE ASCHWANDEN: Yeah, that’s a great question. I didn’t find any good evidence that Epson salts themselves were helpful for reducing soreness, but what I will tell you is that I did some trials of floating, which is a somewhat similar thing where you’re floating in this tank of saltwater. It’s a very relaxing process, but you can also do this with the Epson salts at home, a nice salt bath. And this is very relaxing. 

And one of the activities that I had while researching this book is that so many of the things that are being marketed for recovery actually do work, but they work because they help you relax and they help you, sort of, kick back and let all of your other cares go away. And you’re taking some time to really take care of yourself. And I think that Epson salt baths are an example of this. 

There’s probably nothing particularly magic about the salts themselves, except that it’s just a very pleasant experience, and so much of a what we really need when we’re trying to enhance recovery is just a way to help ourselves relax. I mean, we’re at a moment now in our culture where this is very difficult to do. And so I would just advise people that if there is something that you’re doing that’s helping you read you relax, then it doesn’t matter if you have some fancy scientific explanation for it. Just the fact that it’s helping you feel better and relax and let go of some of your stress, that’s enough. 

IRA FLATOW: Right. We have a tweet coming in. It says what about eating 20 grams of protein after a workout to rebuild muscle? 

CHRISTIE ASCHWANDEN: Yeah, that’s another really good question. So protein is an interesting thing. It used to be that people thought that this was just for meat heads and if you’re a weight lifter maybe. Now there’s recognition that protein is important for all athletes. But we used to have this idea that it was really that you get this protein in right away after you exercise. There is the notion that there is an exercise recovery window, and sometimes it was said to be 20 minutes. It might be as long as 45, but the idea was that you just had to get this right away. 

And subsequent studies and as researchers have continued to look at this issue, what they found is that it’s the protein itself, which is important for athletes, that was, sort of, producing the benefit. And the timing wasn’t the thing that was the most important. And so 20 grams is a number that’s often thrown around as something that athletes should get. 

And I think that that’s a pretty good guideline, but I think the thing to keep in mind here is that this protein can be taken in throughout the day. It doesn’t need to be taken in one big shake right after the workout. And so, yes, protein is important, but you can stop stressing so much about getting it right away or getting it in one giant serving. You can just continue to eat protein throughout the day, and that seems to even be better than just taking it all in at once. 

IRA FLATOW: Let’s go to Orlando and Nikita. Hi, Nikita. Welcome. 

NIKITA: Hi. 

IRA FLATOW: Go ahead. 

NIKITA: Well, I was just going to call and say I’m an Circus So Le performer. I’ve been performing since I was eight years old, and I’m 23 years old now. And I just wanted to respond to what she was saying about stretching, and how it’s basically saying that it’s false claims to stretch. I disagree with that immensely. 

For us, we spent multiple hours a day stretching and warming up every morning and every night after and before the performances. And that’s one of the main reasons why we’re not seeing any injuries. So I was just saying that saying that stretching doesn’t do anything is just not true. I’ve seen it firsthand. 

IRA FLATOW: OK, thanks for the call. 

CHRISTIE ASCHWANDEN: Any reaction? Yeah, I mean, I would just say that if you’re someone who is stretching and you feel like it works for you, it’s not something that seems to be very harmful. Go ahead and keep doing it. When they’ve done studies looking at it and comparing people who stretch to people who didn’t, they didn’t find differences. But again, this goes back to the idea that if you have a ritual or something that you’re doing that feels helpful to you, that may be worth doing for its own sake. 

IRA FLATOW: Dimitri tweets what about a percussive massage tools? 

CHRISTIE ASCHWANDEN: I think these are those. There’s tools now that look like things that you got out of your woodshop or garage. These power tools that sort of a motion and beat at your muscles, and I can tell you that these can feel pretty good. I have a section in the book about massage, and it’s interesting. There are a lot of claims that are made about massage, one of them being that it’s flushing lactic acid out of the muscles. 

And I’ll just say that when you start to see claims about lactic acid, you know that you’re, sort of, getting into red flag territory here. Because lactic acid– we used to think it was something that made you sore. Now we know it doesn’t make you sore, and in fact your muscles clear it quite quickly. So you don’t need to worry about flushing that. 

But what I did find with massage is that it’s something that helps people feel better, and this qualitative sense of wellness is really important. And it really matters. And I think this is a really good example of this idea that if we can get something that we can measure and that’s very tangible and measurable, some sort of data point that that somehow is more important or more real than a feeling of well-being. But when people have looked at recovery, one of the best tools for, sort of, measuring it or predicting it is actually something like mood, and that’s something that, sort of, you can’t measure on a sports watch right. 

IRA FLATOW: Right, I’m Ira Flatow. This is Science Friday from WNYC Studios. We have just a few minutes left, and a lot of people are calling in. Let me go to the opposite direction to Jenny in Harrisonburg, Virginia. Hi, welcome. 

JENNY: Hi. 

IRA FLATOW: Hi there. Go ahead. 

JENNY: So I have a question about using heat on your muscles instead of cold for recovering from a run. I’ve noticed that my lower back hurts a lot after I run, and if I use a heat pad on low setting, it seems to relax my muscles. Is there anything wrong with that? 

CHRISTIE ASCHWANDEN: No, I don’t think so. And in fact, I think heat is a really nice way of relaxing. Heat actually increases blood flow, and that can be a good thing. If you think about the reasons why I think it isn’t helpful, you can imagine that heating would be helpful because instead of slowing blood flow it’s actually increasing it. So it’s sort of opening up the blood vessels and allowing more to flow through. 

There’s an idea that that can help speed the removal of metabolic, things that are left after your exercising. So I say if heat makes you feel good, go ahead and do it. It’s probably a pretty good thing to do, and it’s certainly very relaxing. 

IRA FLATOW: Oh, and one final question. I think I’m running out of time, but it’s an interesting one. And you begin your book about– and it’s a tweet from a Tanis who says what about having a beer? 

CHRISTIE ASCHWANDEN: Yeah. 

IRA FLATOW: A beer after a long day or working out, does that help? 

CHRISTIE ASCHWANDEN: Yeah, so the very first chapter of the book is actually about this very question. It’s about beer and running, and it describes a study that I did to try and answer this age old question is beer the perfect recovery drink. And I think you’ll have to read the chapter to get the gist of the full story, but I guess the takeaway is that beer isn’t the worst thing that you could do. You shouldn’t have more than one, but it’s probably not going to wreck your recovery. 

If it’s refreshing and it helps you, sort of, enjoy yourself afterwards, it’s probably not too bad. But like I said, you will get much more from the book itself. It goes until a lot of detail about the science of this. 

IRA FLATOW: And then you also talk about how you can overdo it so much that you can’t recover. There are some people who just don’t recover. 

CHRISTIE ASCHWANDEN: Yeah, that’s right. I have a chapter about something called overtraining syndrome, and this is pretty common in elite athletes. Although it’s not uncommon among hardcore weekend warriors too, and this is something where people are exercising so hard and not giving themselves enough time to recover that their bodies just, sort of, at some point give out and say no more. And what happens is you stop adapting to that exercise, and you’re just under the stress. 

And people’s performance goes way down. They stop responding to exercise. They don’t feel like exercise. There are a lot of the symptoms are very similar to depression, in fact, and that’s, sort of, a related thing. So it’s really interesting, and this is why it is really important to pay attention to recovery. 

There’s an idea now that it’s not that– it’s not so much that you’re overtraining. It’s that you’re under recovering. And so if you really want to get through those hard sessions of training, you need to, sort of, give yourself equal recovery time. 

IRA FLATOW: Interesting read. If you want to read more about what Christie has written, the name of the book is Good to Go. It talks about the science of recovery. Christie Aschwanden, science writer and author, welcome– thank you for taking time to be with us today. 

CHRISTIE ASCHWANDEN: Thanks for having me.

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