Do Endurance Sports Damage Your Brain?

Summary

Podcast Summary: Chasing Life — "Do Endurance Sports Damage Your Brain?"

Host: Dr. Sanjay Gupta (CNN Podcasts)
Date: February 10, 2026

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Episode Overview

In this episode, Dr. Sanjay Gupta examines the complex relationship between endurance sports, injury risk, and long-term brain health. He addresses listener questions about the safety of turf versus grass in youth sports, the potential health risks of artificial turf, and whether intensive endurance exercise could increase the risk of neurodegenerative diseases such as Parkinson’s, Alzheimer’s, and ALS. Drawing on the latest research and expert insights, Dr. Gupta breaks down what the science really says about how we play, train, and chase longevity.

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Key Discussion Points & Insights

1. Grass vs. Turf: Injury Risks in Youth Sports

Segment Start: [02:21]

• Listener Question: Are turf fields more dangerous than grass for young soccer players?
• Dr. Gupta's Summary:
  • Recent studies, confirmed by the Academy of Pediatrics, show no overall difference in injury rates during games played on grass or turf ([02:21]).
  • “During games between turf and grass, not a huge difference. But during practices and training, grass ended up being associated with more injuries.” – Dr. Sanjay Gupta [02:53]
  • Lower extremity injuries are higher during practice on grass, possibly due to worse field maintenance (divots, water pooling, uneven surfaces), leading to more injuries.
  • Advice for parents: Always inspect field conditions—check for debris, holes, or excess water, regardless of surface.

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2. Types of Injuries: Differences Across Surfaces

Segment Start: [04:04]

• Foot and ankle injuries are more common on artificial turf, while knee and hip injuries occur at similar rates on both surfaces.
• Most other injuries are more common on grass.
• “If you look at the overall number of injuries on turf versus grass, they're about the same. But if you start to zero in on the body part, a different picture starts to emerge.” – Dr. Sanjay Gupta [04:26]
• Improvements in turf technology have made surfaces more similar to grass compared to early generational “Astroturf.”
• Results may vary by sport or population, but the general risk remains approximately equivalent.

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3. Artificial Turf & Toxicity Concerns

Segment Start: [05:48]

• Listener Question: Do “crumb rubber” infill particles (made from recycled tires) used in turf fields pose a cancer risk?
• Expert Input: Nick Pappas, NFL field director:
  • “We don't have any concerns over toxicity right now… we haven't run into any concerns with toxicity from a crumb rubber perspective or any of our natural infills.” – Nick Pappas [06:34]
• Dr. Gupta explains that, although crumb rubber contains carcinogens as recycled tires, population studies have not demonstrated increased health issues tied to turf exposure.
• Current research finds no cause-and-effect link between turf and diseases in people with normal exposures.
• “At the population level, there's been no data suggesting a cause and effect relationship between turf and some of these medical problems.” – Dr. Sanjay Gupta [07:02]

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4. Does Endurance Exercise Increase Neurodegenerative Risk?

Segment Start: [09:03]

• Listener Question: Can long-term, strenuous exercise raise the risk of diseases like Parkinson’s, ALS, or Alzheimer's?

• Summary of Evidence:

  • Overall, exercise is very protective – it can slow or delay neurodegenerative diseases.
  • Parkinson’s Disease:
    • 2024 Yale study found high-intensity aerobic exercise preserves dopamine-producing neurons ([09:49]).
    • May not prevent disease completely but could delay onset (“motor reserve” effect).
    • “That doesn’t just slow down the disease, it could actually help the brain repair itself.” – Dr. Sanjay Gupta [10:10]
  • Alzheimer’s Disease:
    • As little as 35 minutes/week of moderate exercise linked to a 41% lower risk of dementia ([10:34]).
    • Exercise stimulates growth of new brain cells and neurotrophic factors – “miracle growth for the brain.”
  • ALS (Amyotrophic Lateral Sclerosis):
    • Higher ALS rates have been observed in some professional athletes (e.g., soccer, football), possibly due to repetitive head trauma, not exercise alone.
    • Genetic Factor: A rare variant in the C9orf72 gene may increase ALS risk when combined with intense physical stress, but this is rare and research is very new ([11:40]).
    • For most people, intensive exercise is safe and beneficial.

• Gupta’s Practical Advice:

  • Listen to your body and know your family history.
  • Risks typically appear only for extreme endurance athletes.
  • For the majority, benefits far outweigh any theoretical risk.
  • Increase training slowly and with a structured program.

• Memorable advice:

  • “No need to feel guilty about that runner’s high. I’m right there with you.” – Dr. Sanjay Gupta [12:50]

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Notable Quotes & Timestamps

• “During games between turf and grass, not a huge difference. But during practices and training, grass ended up being associated with more injuries.”
  – Dr. Sanjay Gupta [02:53]
• “If you look at the overall number of injuries on turf versus grass, they're about the same. But if you start to zero in on the body part, a different picture starts to emerge.”
  – Dr. Sanjay Gupta [04:26]
• “We don't have any concerns over toxicity right now… we haven't run into any concerns with toxicity from a crumb rubber perspective or any of our natural infills.”
  – Nick Pappas, NFL [06:34]
• “At the population level, there's been no data suggesting a cause and effect relationship between turf and some of these medical problems.”
  – Dr. Sanjay Gupta [07:02]
• “That doesn’t just slow down the disease, it could actually help the brain repair itself.”
  – Dr. Sanjay Gupta [10:10]
• “No need to feel guilty about that runner’s high. I’m right there with you.”
  – Dr. Sanjay Gupta [12:50]

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Key Takeaways for Listeners

• For youth sports, choose well-maintained fields regardless of surface; both grass and turf have similar injury rates overall.
• Foot and ankle injuries may be higher on turf, but other injuries (and context like practice vs. games) matter more.
• Artificial turf’s “crumb rubber” is not currently shown to increase cancer or toxicity risk based on population studies.
• Regular exercise is overwhelmingly beneficial for brain and whole-body health; only extreme endurance (plus rare gene variants) might pose added risk.
• If you’re not a professional or ultra-endurance athlete and have no relevant family history, keep moving — your brain and heart will thank you.

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For further questions, Dr. Gupta invites listeners to submit voice memos or call in, emphasizing the evolving nature of research and the value of staying informed.

Transcript

[Dr. Sanjay Gupta]

Hey there. Welcome to Paging Dr. Gupta. Thanks so much for joining us. We got a lot of questions that came in this week, so I'm going to dive right in. Jesse's with us. Who do we have first?

[Jesse]

Hey, Sanjay. So, as you know, the Seattle Seahawks just won the super bowl and we have a bunch of questions related to the big game, mostly about playing sports on turf or grass? So Sarah from Colorado asks, my daughter, seen a shift from playing soccer on mostly grass fields to almost all turf fields. How do rates of minor injury compare on the two surfaces?

[Dr. Sanjay Gupta]

Okay, Sarah, thank you for the question. First of all, I can tell you that I've noticed this same transition with my own kids. A lot more turf fields as compared to mostly grass fields when I was growing up, and I think it's smart to ask if that's really the safest option for our children. So I've done a lot of reporting on this topic. I'm a doctor, but I'm also a sports fan. I talk to a lot of folks at the NFL who are looking into this, and I can tell you this grass versus turf debate is one of the big ones that's happening in professional sports. So I'll share with you what I know right after the break.

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[Zach]

What is it about Australia that just hits different Australia is.

[Laura]

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[Zach]

And this is what, your fourth trip back?

[Laura]

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[Dr. Sanjay Gupta]

Okay, we're talking about how often minor athletes get injured playing on turf fields compared to grass fields. Youth soccer, specifically. So the Academy of Pediatrics. First of all, they recently reaffirmed the findings of this big review of soccer injuries. And the headline was recent studies have shown no difference in overall injury rates during games that are played on grass or turf. And I'm highlighting the word games here as opposed to practices because lower extremity injury rates were higher during training, during practices Actually, on grass, I think that surprised a lot of people. So, again, during games between turf and grass, not a huge difference. But during practices and training, grass ended up being associated with more injuries. In fact, According to a 2016 study, they found kids playing soccer who got injuries were almost twice as likely to have been playing on grass. I think part of the reason here is that for youth soccer, the surfaces may not be maintained as well, especially during practices. So there may be divots in the grass, there may be water pooling, there may be uneven surfaces, and that is probably what's leading to more injuries on the grass during practices. I think the message for parents here is you got to make sure you're checking the condition of the field before playing, whether it is game or it is practice. Checking for debris or holes or excess water. Those things can cause injury. Addressing them ahead of time can prevent the injury.

[Jesse]

Okay, great. And Mike wants to know, are the types of injuries consistent across both types of fields?

[Dr. Sanjay Gupta]

Right. So that's the next big question. There was this big review of the scientific literature, 53 articles published over nearly 50 years between 1972 and 2020. Keep in mind, turf really came about in the mid-1960s. It was used before that, but it became quite popular at the Astrodome, which is why the first turf was called Astroturf. And now all sports, all levels of competition, all turf types have been included in these various studies. Some of the early studies, the early days, I think it's fair to say that the turf wasn't that good. It just wasn't that good. And there were a lot more injuries over the years. The turf has improved. It's become more like grass. But what's interesting is that if you look at the overall number of injuries on turf versus grass, they're about the same. But if you start to zero in on the body part, a different picture starts to emerge. So, for example, foot and ankle injuries higher on artificial turf compared with grass. Knee and hip injuries about the same turf or grass, but just about all other injuries more common on grass. So, overall number of injuries around the same, foot and ankle injuries more common on turf. Bear in mind, this is a broad review, and when you zero in on specific sports or smaller populations, you may get slightly different answers to this question.

[Jesse]

All right, last question on this topic. It comes from Anna in Liberty, Missouri. She wrote, in my understanding is that artificial fields in all sports are dressed up with ground tire rubber. You see some kind of particles flying up during games. But aren't rubber tires classed as a.

[Dr. Sanjay Gupta]

Carcinogen yeah, Anna, I love this question. I think this is a valid concern, talking about crumb rubber specifically. If you've watched games, you've seen those black particles sort of fly up when someone gets tackled. I had a chance to talk to Nick Pappas. He's the guy who is the field director for the NFL. He determines field surfaces for big games, including the Super Bowl. He was the guy that determined that grass would be used for the super bowl and that that grass would be Bermuda grass. It was grown over 18 months at a sod farm. He's the guy that does all this. He's very familiar with surfaces and here's what he told me. What's the concern about toxicity? When I was looking in this, they said if I touch this stuff, I should wash my hands immediately after.

[Nick Pappas]

From our perspective, working closely with the manufacturers, working with our own specialized individuals on the NFL, NFL, PA side, we don't have any concerns over toxicity right now. There's obviously anytime you're out in the elements, there's, you know, you're within, whatever's around you. But here, whether you're inside or outside, we haven't run into any concerns with toxicity from a chrome rubber perspective or any of our natural infills or the various infills that are out there.

[Dr. Sanjay Gupta]

Okay, so valid concern because we're talking about crumb rubber, which comes from recycled tires. Recycled tires contain carcinogens, cancer causing agents. So the question is, is that going to be a problem? And I think what Nick is saying is that if you look at the population studies and you look at people who have a lot of exposure to turf, they're not seeing an impact. They're not seeing people get sick or develop other problems as a result of lots of exposure to tirf. So at the population level, there's been no data suggesting a cause and effect relationship between TIRF and some of these medical problems. This is a really fascinating issue and no surprise we got so many questions. Thanks for those questions. We're going to take a quick break. When we come back, we're going to talk about the role exercise plays in preventing neurodegenerative diseases. We'll be right back.

[Zach]

What is it about Australia that just hits different.

[Laura]

Australia is where we shared our first.

Kiss, where we fell in love. That was 18 years ago now.

[Zach]

And this is what, your fourth trip back?

[Laura]

Australia has this incredible way of drawing you back.

The ocean, the people, the oysters. So good, so briny and delicious. And the possibility of exploring, exploring something new.

[Zach]

Learn more about Zach and Laura's [e-mail] and start planning the vacation of a lifetime.

[Laura]

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[Dr. Sanjay Gupta]

All right, that sound means we're back. Jesse, who's up next?

[Jesse]

Okay, so we're going to stick with our sports theme today. Sahar in D.C. is 24 years old and she's followed your reporting on the role exercise plays in battling dementia. But she's wondering if there's more to the story. Check it out.

[Sahar]

I've recently gotten into exercising regularly and I know that it plays a very important part in keeping sharp. And I'm just worried a little bit about the recent links to long term strenuous exercise, marathon running, when it comes to other neurodegenerative diseases like Parkinson's or als. And I just wanted to know your thoughts on that. Can this long term intensive exercise increase your risk for those diseases? Thank you so much. Bye.

[Dr. Sanjay Gupta]

All right, Sahar, first of all, as a fellow runner, I hear you. The idea that something as healthy as exercise could have this dark side, that's alarming, obviously. But like most things in medicine, the answer is not a simple yes or no. Think about the dose and think about your own biology. So let's look at the evidence because I think this is actually quite fascinating. First of all, you're quite right. We have a lot of evidence that exercise in general is, is a good thing, a really good thing when it comes to preventing or slowing down neurodegenerative diseases. Take Parkinson's disease. A 2024 study out of Yale showed that high intensity aerobic exercise could help preserve what are known as dopamine producing neurons. When you develop Parkinson's, you lose those neurons. Exercise can help preserve that. That doesn't just slow down the disease, it could actually help the brain repair itself. Now, let's talk about distance training. Specifically, 2020 study out of Sweden compared the Parkinson's disease risk of long distance skiers who participated in a big race to the general public's risk. The skiers initially had a close to 30% reduced risk, but over time, that gap Narrowed that benefit became smaller. After 15 years, their risk basically looked similar to everyone else's. So that suggests that the exercise provides what scientists call a quote unquote, motor reserve to ward off the disease for a time, rather than permanently protecting the brain. So think of that as delaying the onset of a problem as opposed to preventing it completely. We also see the massive benefit of exercise when it comes to Alzheimer's. Recent study out of Hopkins found as little as 35 minutes of moderate exercise per week was linked to a 41% lower risk of dementia. This is really, really inspiring stuff. I mean, if you think about what's happening in the brain, we know we can create new brain cells throughout our lives. And we also know that exercise is one of the things that helps make that happen. It helps create these specific neurotrophic factors, which, as one neuroscientist said to me, is kind of like miracle growth for the brain. Now, most of the concern I think you're talking about stems from something known as als. Amyotrophic lateral sclerosis, or you may know it as Lou Gehrig's disease. For years, we've seen higher rates of ALS in certain professional athletes, soccer, football players. But even then, researchers note that one risk factor for soccer and football players is that they're taking repetitive hits to the head. Right? So studies suggest that for the vast majority of people, that's not gonna be the case, and strenuous exercise is. Is not only gonna be safe, but actually beneficial. Now, I will say, and this is rare, but for individuals with a specific variant of something known as the CNORF72 gene, I'm gonna repeat that just in case you wanna write it down. C9orf72 gene. And people who have a specific variant of that gene, intense physical stress might. Might act as a trigger for als. I just want to throw that out there. It's rare. The research is still emerging, but I think it's important for you to know the science around this is pretty new, just within the last five years. So we don't know, for example, if other environmental factors may be playing a role here as well. So what's the bottom line, Sahar? I think, number one, listen to your body. If you have a family history of motor neuron disease, it might be worth having a deeper conversation with a specialist. Number two, remember that most of the risks, they tend to appear at the extreme ends of human endurance, so don't overdo it. And number three, for the vast majority of us, the cardiovascular benefits, the cognitive benefits of training for a marathon or any kind of exercise for that matter, far outweigh the risks. So I hope that gives you some peace of mind next time you're out on the trail. No need to feel guilty about that runner's high. I'm right there with you. And if you do decide to go for it, Sahara, make sure you follow a training program and add the miles on slowly. I don't want you to be calling back with some question about a new runner's injury. Thanks for all the great questions this week. I love going down the rabbit holes with you. If you have something on your mind, record a voice memo. Email it to pagingdr.gupta.com that's paging Dr.gupta.com or give us a call 470-396-0832 and leave a message. I'm Dr. Sanjay Gupta. Talk to you soon.

[Zach]

What is it about Australia that just.

[Laura]

Hits different Australia is where we shared our first kiss.

Where we fell in love. That was 18 years ago now.

[Zach]

And this is what your fourth trip back.

[Laura]

Australia has this incredible way of drawing you back.

The ocean, the people, the oysters. So good, so briny and delicious and the possibility of exploring something new.

[Zach]

Learn more about Zach and Laura's [e-mail] and start planning the vacation of a lifetime.

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[Zach]

Yes, it is. I don't think that I thought that I would be able to have as much joy as I've had. I guess if I wasn't able to find joy and laughter now, I would have missed the point of Andrea's messaging.

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