How Does Long-Distance Running Affect Your Body?

For answers to the running Q&A, scroll to the bottom. 

RACHEL FELTMAN: This is Science Friday. I’m Rachel Feltman. While all marathons are the same length– that’s common sense, I fear some– definitely loom larger than others in competitors’ hearts. The New York City Marathon is definitely up there. This Sunday, more than 50,000 runners are expected to compete in it.

Running any marathon is a huge physical accomplishment. It means hoofing it for 26.2 miles or more than 42 kilometers. That amounts to several hours of running, even for the most elite marathoners on the planet. So what exactly goes on in the human body when it runs for hours on end?

We collected some of your questions on social media and found an expert to clue us in. Joining me to give us some answers is my guest, Dr. Brandee Waite, director of Sports Medicine at UC Davis Health in Sacramento, California. Welcome to Science Friday.

BRANDEE L. WAITE: Thanks, Rachel. I’m so happy to be here.

RACHEL FELTMAN: Before we get into some of the awesome questions we got from our listeners, let’s talk about your qualifications. It’s my understanding that you’ve worked with a lot of marathoners over the years.

BRANDEE L. WAITE: Oh yes. I love my running patients. So I’ve been a medical director for the California International Marathon for 10 years. And during that time, plus the 10 years prior to that, I’ve worked with an ultramarathon running company that puts on ultramarathon races around the world called RacingThePlanet.

And so since 2005, I’ve been working with a lot of distance, marathon, ultramarathon runners. I’ve worked with USA Track & Field. So my running patients are near and dear to my heart. I love helping them reach their goals.

RACHEL FELTMAN: That makes sense. All right. Let’s dive into some of the questions we got from our very motivated listeners.

KAYLA KAISER: Hey, Science Friday. This is Kayla Kaiser from Los Angeles. And I’m training for the LA Marathon 2025. I had a long run today of eight miles. So my question for you is, What are some of the mistakes that first-time marathoners make?

I have never done a full marathon. I’ve only done halves before. So what are the common mistakes that I can avoid in my training? Thanks so much.

BRANDEE L. WAITE: Yes. Ooh, I love this question because first-time marathoners are such a fun group to work with. I think that one of the main things that first-time marathoners do that might get them into trouble is not train enough for the marathon. Sometimes people feel that they have a general level of fitness, and that might translate to being able to run a marathon even if they haven’t really done that distance before. And there are very few people who can translate other fitness into running a marathon, basically.

RACHEL FELTMAN: Sure.

BRANDEE L. WAITE: Almost everybody– pretty much everybody really needs to train and train properly. So if you’re not educated on the right type of training, the type of cross-training, when you need to rest, when you need to go, how many miles you should increase per week, you can get yourself into trouble. So following a training program by somebody who knows what they’re doing, and something that’s gradual without big jumps at any given time is a much better pathway to avoid that pitfall of under training for the marathon.

RACHEL FELTMAN: Absolutely. Great advice for trying to hit any fitness benchmark. But I think especially for marathoning, definitely not something you want to jump into lightly.

BRANDEE L. WAITE: Yes. One more pitfall that first-time marathoners– and even just marathoners who are coming into a big event, maybe a bigger venue like New York City marathon or some of the other big marathons, even if they’ve run smaller ones before, is getting too excited at the starting line and going out too fast. And they don’t stick with the plan that they’ve had for the pace because things are so exciting at the starting line.

And if it’s not too crowded– people worry if it’s very crowded, you’re not running up to your speed, but just stick with the pace that you’re supposed to be at, even if you feel great and energized, because about five miles, 10 miles, 18 miles in, you’ll really wish that you had kept with the pace so that you don’t hit a big wall and just collapse before the finish line.

RACHEL FELTMAN: Oh, absolutely Let’s go on to our next question.

PETER BARBER: This is Peter Barber.

DAN NETHAN: I’m Dan Nethan.

PETER BARBER: We’re from Lancaster, Pennsylvania. And between the two of us, we have 100-plus marathons, a bunch of ultramarathons, a bunch of triathlons. We just finished 15 miles along the beautiful and mighty Susquehanna River.

I suppose my question for you all is, Why do I have such a sense of mental clarity when I’m running? It feels like I can solve all the problems, find resolutions to things that have been bothering me, and have clarity of thought and idea. Thanks a lot. Love Science Friday.

BRANDEE L. WAITE: Ooh. Peter has a great question. I think it dances on the edges of a couple of things. One of the things it dances is on is the edge of meditation and moving meditation. And so the combination of exercise, by increasing your circulation in your muscles, it also helps to increase the circulation in your brain. So that can help with clarity.

I think people who do quote unquote “naked running,” if they run without AirPods or run without music or run without sound and they’re just kind of in nature on their run without things distracting them is really a time when you can get mental focus. A lot of our lives, we are distracted by our bodies, by things pinging, by our watch going off, by people trying to get our attention, by trying to stay safe in the environment you’re in.

And so when you’re running, and if you’re running in a safe-bet space, and you can just kind of get in the zone, so to speak, really have so much fewer distraction pulling your brain to other things. And it’s very common for people to say, I come up with my best ideas when I’m running. People talk about endorphins, too, and the runner’s high, and there’s a little bit of scientific controversy, actually.

The endorphins that your body produces that are type of hormone, they don’t actually cross the blood-brain barrier. So it’s hard for them to get from your blood into your brain. But there’s another substance in the body that increases with exercise, and that’s endocannabinoids. And these are natural substances that increase in your body when you’re exercising. And they do move easily across the cell border that separates the bloodstream from the brain.

And these are mood-improving natural substances. And so they can have kind of short-term brain enhancing effects that can help reduce anxiety or improve feelings of calm, and that can give people better focus.

RACHEL FELTMAN: Very cool. Our next question is from Kaylee in White River Junction, Vermont.

KAYLEE: My question is, Is running bad for your knees? I do a lot of strength training to prevent knee damage or pain and aches and pains come with running, but am I actually deteriorating my joints.

BRANDEE L. WAITE: Your listeners have great questions. I love Kaylee’s question. And I’m very happy to tell her, no. Running does not deteriorate your knees. There is no higher incidence of arthritis in runners than there is in the general population. So actually, runners who do recreational running have a lower incidence of knee arthritis than people who are sedentary.

And she also really keyed into the fact that she’s doing strength training as well to help offset that. And that is a wonderful pairing. The strength training to help build the muscles like you’re building a brace around the joint from the inside out, and then the running itself actually is beneficial for circulation, which can only help joints to feel better.

Now there are people, if you have an underlying knee problem, running, can make it worse depending on the type of problem. But running itself– yeah, running itself does not increase the degeneration of knees.

RACHEL FELTMAN: Awesome. Let’s move on to our next question.

AUDIENCE: I just completed a 17-mile training run and I am training for my first 50k, the Tucson Marathon on December 15. My question is, there’s a lot of conflicting information on recovery, whether you should let your body have inflammation, whether you should take ibuprofen, whether you should stretch or not stretch. So my question is, Right after a long run, both physically and nutritionally, what are your recommendations?

And then again, 24 and 48 hours, what are your recommendations to sort of let your body recover optimally for the next run? Thank you.

BRANDEE L. WAITE: This is a good question. And it kind of depends on which camp of medical experts you talk to. But in general, inflammation does serve a purpose in the body. It helps with healing. Too much inflammation, though, of course, can cause pain and can cause a limitation in training programs. And inflammation can get out of control to the point where it’s overdoing more than you need it to do and actually causing harm rather than causing good.

So after a long run, I recommend people use ice or cold immersion. This can really help to reduce the inflammation in the joints and in the muscles. This is good to use in the first 24 hours after a long run. I would say within the first hour after a long run would be ideal. And I don’t necessarily recommend, though, using anti-inflammatory medications at this point.

Many times when people have been running long distances, they’re relatively dehydrated and your kidneys really need good hydration in order to process the anti-inflammatory medications properly and not lead to other issues. So I usually recommend that people hold off on using anti-inflammatory medicines until they’re really fully well rehydrated

The next day, so when you have that delayed onset muscle soreness, gentle stretching is OK. If people try to do stretching that’s too vigorous when the muscles are really tight, they can actually cause more muscle tearing or damage. So a balance of cold for anti-inflammatory and gentle stretching is fine. If people really are in a lot of pain or they notice they’ve got significant swelling in a joint, then the anti-inflammatory medicine is good for reducing swelling that might be going on the next day or even two days after a long run.

RACHEL FELTMAN: Let’s move on to our next question. We have a caller from California.

AUDIENCE: Good morning. I’ve been an ultra runner for over 20 years and trail running for over 30. I am 52 years old. And ever since I hit my 50s, the injuries have been coming and I’m not liking it at all.

And I guess my question is, What role does changing hormones, a.k.a., perimenopause, menopause, play in a long-distance trail runner or any female athlete as she ages? It seems to affect so many things. I’m curious how it affects joints and muscles.

BRANDEE L. WAITE: Yeah, this is a very timely question actually. This month, October, in the medical journal Climacteric, there was a fantastic article titled “The Musculoskeletal Syndrome of Menopause.” And it has been something that kind of flew under the radar for a long time in medicine, as a lot of women’s health issues do.

But many perimenopausal and postmenopausal women notice that there seems to be an increase in the aches and pains just getting from day to day, but especially with exercise and activity. And in this article, it had data that about 70% of women will experience musculoskeletal symptoms, meaning pain or aches or injuries of the muscles, bones, and joints. And up to 25% will actually be disabled by this.

And this is an– I mean, this is a huge statistic that you could have 25% of people, 25% of women, experiencing joint pain, joint injuries, muscle problems that limit their ability to participate in the activities that they want to do. That’s a definition of being partially disabled by this issue. So, yes, estrogen is basically protective for the cartilage.

So estrogen protects cartilage. In perimenopause and postmenopause estrogen levels go down, and we actually see that arthritis progresses more quickly during this time frame. So if you took X-rays of someone’s knees when they were in their 30s and again in their 40s and again in their 50s and in their 60s, the progression of arthritis or the degeneration of that joint speeds up during perimenopause and postmenopause. And that’s due to the decrease in estrogen protection.

So it’s not in your brain, and it’s not a death sentence either, or a doom sentence. There are definitely things that can help to reduce the effects of perimenopause hormonal changes on the joints. And that is maintaining a strength training program, using nutrition to help with anti-inflammatory strategies, so maybe not anti-inflammatory medicines, but eating a diet that’s rich in foods that don’t create as much inflammation when your body digests them, and continuing to make sure that cardiovascular exercise for your vascular health stays in place so that you’ve got great blood flow and blood supply to the muscles and the tissues that support exercise.

RACHEL FELTMAN: All right. We’ve got time for one more question. This one is from Rob in Memphis, Tennessee.

ROB: I just finished a 13-mile run. It’s a training run. I’ll be running a marathon in December. And I ran with some friends today. And running with friends is always a great experience. As an older runner, I’m 65, I’d like to know, What can I do to continue running even into my 60s and 70s and beyond? What’s necessary to be able to maintain a high level of fitness and conditioning and avoid injury?

As I know my body will begin to deteriorate some and all the stresses of exercise can take a toll. So how do I keep doing this for as long as possible? Thank you.

BRANDEE L. WAITE: I love this question because it focuses on maintaining function and continuing to be able to do the things that you enjoy in life, well into 60s, 70s and 80s. And there are strategies that can help people be more successful in being more fit and tolerate activity longer. That includes making sure they’re doing some cross training. So just the high-intensity, high-impact exercise can be harder to maintain over time.

So having cross training, including stretching, having good nutrition, all of these things, really, it’s the whole package that you’ve got to do in order to keep your running going well into your later decades. I take care of a lot of runners who are in their 60s and 70s, and they may change their focus. It’s not so much on speed, but more on distance. They focus on maintaining a healthy weight or a weight that– healthy weight is probably a loaded term, but a weight that their body can carry without really having excess pressure on their joints.

And by building the muscles, having some strength training built in with their running program, again, as I mentioned before, the strength training helps to build the muscles that support the joints almost like building a brace from the inside out, which can decrease some of the aches and pains that come with running. As people age, there’s a natural tendency for the muscles to shrink. It’s called sarcopenia. And that’s a normal process of aging. And so the same amount of resistance training that kept your muscles a certain size in your 30s or 40s will not do the same in your 60s or 70s.

And so that’s OK. It’s part of what goes on. But you may need to actually do more strength training in order to maintain benefits and to fight that sarcopenic muscle loss.

RACHEL FELTMAN: Thank you for all of this advice, all of these answers. That’s all the time we have for now. But again, I’d like to thank my guest, Dr. Brandee Waite, director of Sports Medicine at UC Davis Health in Sacramento, California. Thanks so much for joining us.

BRANDEE L. WAITE: Thank you for having me, Rachel. Good luck out there on your runs, everybody. Keep it going.

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Answers to the running Q&A:

A1: Ooh, Peter has a great question. I think it dances on, on the edges of a couple of things. One of the things that dances on is the edge of meditation and moving meditation. And so the combination of exercise by increasing your circulation in your muscles, it also helps to increase the circulation in your brain.

So that can help with clarity. I think People who do, uh, quote unquote, naked running, if they run without air pods or run without, um, music or run without sound and they’re just kind of in nature on their run without things distracting them, is really a time when you can get mental focus. A lot of our lives, we are distracted by our bodies, by things pinging, by our watch going off, by people trying to get our attention, by trying to stay safe in the environment you’re in.

And so when you’re running, and if you’re running in a safe, that space, and you can just kind of get in the zone, so to speak, you really have so much fewer distraction. to other things. And it’s very common for people to say, I come up with my best ideas when I’m running. People talk about endorphins too, and the runner’s high, and there’s a little bit of scientific, uh, controversy, actually the endorphins that your body produces that are a type of hormone.

They don’t actually cross the blood brain barrier. So it’s hard for them to get from your blood into your brain. But there’s another, substance in the body that increases with exercise, and that’s endocannabinoids. And these are natural substances that increase in your body when you’re exercising, and they do move easily across the cell border that separates the bloodstream from the brain, and these are mood improving, uh, natural substances, and so they can have kind of short term brain enhancing effects, um, that can help reduce anxiety or improve feelings of calm, and that can give people better focus.

A2: Your listeners have great questions. I love Kaylee’s question and I’m very happy to tell her no, running does not deteriorate your knees. There is no higher incidence of arthritis in runners than there is in the general population. So actually runners who do recreational running have a lower incidence of knee arthritis.

Then people who are sedentary. And she also really keyed into the fact that she’s doing strength training as well to help offset that. And that is a wonderful pairing, the strength training to help build the muscles, like you’re building a brace around the joint from the inside out, and then the running itself actually is beneficial for circulation, which can only help joints to feel better.

Now there are people, if you have an underlying knee problem, Running can make it worse depending on the type of problem. So, but running itself, yeah, running itself does not increase the degeneration of knees.

A3: I love this question because it focuses on maintaining function and continuing to be able to do the things that you enjoy in life. You know, well into 60s, 70s and, and 80s. And there are strategies that can help people be more successful in being more fit and, uh, tolerate activity longer. That includes making sure they’re doing some cross training.

So just the high intensity, high impact exercise can be harder to maintain over time. So having cross training, including stretching, having good nutrition, all of these things really, it’s the whole package that you’ve got to do in order to keep. You’re running going well into your later decades. I take care of a lot of runners who are in their sixties and seventies and they, they may change their focus.

It’s not so much on speed, but more on distance. They focus on maintaining a healthy weight or a weight that, um, healthy weight is probably a loaded term, but a weight that their body can carry without really having excess. Pressure on their joints and by building the muscles having some strength training built in with their running program Again, as I mentioned before the strength training helps to build the muscles that support the joints almost like building a brace from the inside Out which can decrease some of the aches and pains that come with running as people age There’s a natural tendency for the muscles to shrink.

It’s called sarcopenia and And that, that’s a normal process of aging. And so the same amount of resistance training that kept your muscles a certain size in your thirties or forties will not do the same in your sixties or seventies. And so that’s okay. It’s, it’s part of what goes on, but you may need to actually do more strength training in order to maintain benefits and to fight that sarcopenic muscle loss.