In the new National Geographic series Limitless: Live Better Now, Chris Hemsworth embarks on a remarkable journey to explore how we can all live better—starting today. Guided by modern science, ancient wisdom, and personal challenges, Hemsworth pushes himself to confront pain and fear. From drumming alongside Ed Sheeran to scaling a sheer Alpine cliff and training with South Korea’s elite forces, each experience offers insights for living a more fulfilling life.

Joining him on this journey is palliative care physician and author Dr. BJ Miller, who brings a meaningful and important perspective on resilience, purpose, and the human capacity to adapt. Known for his widely viewed TED Talk “What Really Matters at the End of Life” and his co-authored book, A Beginner’s Guide to the End, Miller helps Hemsworth and viewers rethink pain, resilience, and the power of a strong mind in living well through every stage of life.

In a world where pain is often misunderstood, new perspectives from science, culture, and storytelling are helping us see it not as an enemy, but as a pathway to resilience. There’s optimism in the field of pain science.

In this interview about Limitless: Live Better Now, we speak with Dr. Miller about the science behind reframing pain as a signal rather than a threat, the lessons Hemsworth learned through extreme challenges, and more.

Pain Science and the Human Brain

Lindsey Feth: I want to dive first into pain science and the human brain. In the series, you explain that pain can sometimes be a signal rather than a threat. How does this understanding change the way we should respond to pain?

Dr. BJ Miller: Well, great question. A really important question for the readers, because sometimes pain is actually a threat. What we need to develop is the judgment to know when pain constitutes a risk and when it is just a nervous system that is hung up and hurting for no good reason.

It is not always easy to tell. Sometimes it is. You put your finger on a hot stove, you move your finger, and the pain subsides. In that case, pain was telling you that you are at risk of a threat, so stop what you are doing, or at least change what you are doing. But, often, it is not so obvious. In those cases, it may be a trip to the doctor to help you discern whether or not you are causing injury.

When you can reasonably assure yourself that this pain does not constitute a risk or threat of injury, then you can start playing with it. Tone down the story around it. Call it a signal. Check how you talk to yourself and watch the meaning you are making from it. You can distract yourself with music or time with friends, but do not do that before you have assured yourself that this pain is not actually a threat.

Building Pain Tolerance

Feth: One of the things I found really interesting in the series was how Chris (Hemsworth) exposed himself to pain over time to try to increase his tolerance. How can exposure, like the physical challenges he endured, actually increase pain tolerance over time?

Miller: You can train your nervous system to read. The periphery of your body, your fingers, for example, does not necessarily know when something is a threat. Your brain is the thing that is charged with discerning that. Over time, you can push the sensation just shy of injury, and your brain will get the signal that this sensation is no longer a threat. This activity with this sensation no longer constitutes a threat.

The next time, you can dial it up a little further, and then further again, and in this methodical way, you can build your tolerance or capacity to deal with that sensation. The important part is that you do this very carefully and with a trainer. Contrast that with throwing yourself into the world in an unchecked way, causing more and more pain without regard to injury. That is a way to traumatize yourself, hurt yourself, and actually lower your pain threshold. The difference is that one approach is controlled and deliberate, while the other is haphazard and dangerous.

Eastern vs Western Philosophy

Feth: One of my favorite parts of episode two was when you were in the monastery with Chris and the monks. I wrote down a line one of the monks said in the episode: “Your thoughts make suffering reality.” How do Eastern and Western philosophies differ in the way we talk about and experience pain?

Miller: Eastern philosophy, meaning cultures that are much older than American Western culture, has been around for a long time, dealing with the realities of life. If you have been around the planet for a long time, you will come to realize that pain is part of life. It is not something you can avoid or remove from your experience.

The wisdom of the monks is that their sense of reality includes pain. Therefore, it is not this obnoxious foreign invading threat. It is simply part of life. That alone can shift your story around pain.

In the West, we tend to presume that pain is optional or avoidable. If you do everything perfectly and keep running from it, you will somehow avoid pain. When it happens, we often see it as a failure or a weakness. That is a terrible story to tell yourself about something you ultimately cannot avoid.

So the big difference is that one philosophy embraces pain as part of life, while the other goes to war with it. For my money, the former approach is much more durable.

Chris Hemsworth’s Transformation

Feth: Chris pushed himself through electrocution, pepper spray, and more. That final special forces challenge was intense to watch. What was it like observing that transformation firsthand?

Miller: For Chris, it was great watching him throughout this episode. You could feel him take it all very seriously and really put himself out there. I was proud of him. He made himself vulnerable, put himself in difficult situations, and trusted a lot of people in the process. On one hand, it was inspiring to watch him work so hard and really commit.

On the other hand, it was a little hard for me to watch. It felt a bit sadistic. My life’s work is helping people hurt less, not more. So, having this contrived way of causing pain was not so much fun for me. But I trusted the production crew and everyone else involved that we were not going to hurt anybody.

BJ’s Story

Feth: In the series, you opened up about becoming a trilateral amputee in college. How has that shaped your personal relationship with pain while being part of this project?

Miller: For me, much like those monks, my life included a lot of pain early on. I had to come to terms with the fact that pain was going to be part of my experience. It was not a foreign invader knocking at my door. It had already moved into my house.

I learned early that I could not just push it out of my experience. I had to turn toward the pain rather than run away from it. I had to find a way to develop a lasting relationship with it, or else I would be at odds with myself and with reality, and I would hurt even more.

It was unfortunate, of course, to have so much pain at a young age, but in some ways, I am grateful. It caught me early and taught me how to deal with this force that was going to come my way one way or another.

Takeaways from Limitless: Live Better Now

Feth: What do you hope viewers will walk away with after watching this episode of Limitless with Chris?

Miller: I hope people understand that pain is complicated. It is not as simple as saying that if you hurt, you are weak. I hope we all come away with a more mature understanding of what pain is and the complexity behind it.

I also hope people recognize that pain is entirely subjective. Any two people will experience it differently, even if the stimulus is the same. I hope viewers will respect each other’s and their own experience of pain and be careful about comparing or judging. We suffer so much more than we need to with all our judgments.

And finally, I hope people remember that all pain is real, even if you cannot see the stimulus. Emotional pain, existential pain—whatever its source—it is no less real. Just because it is in the brain does not make it fake. Start with kindness to yourself and to others.

Blending Science and Storytelling

Feth: How do you see this kind of storytelling, blending science, culture, and celebrity, helping reshape conversations about health and wellbeing?

Miller: Even though pain is universal, many of us labor under the false notion that we are alone with it. We suffer in silence and hurt more because of it.

This blend of entertainment, education, and celebrity is a wonderful way to normalize these experiences. Look at someone like Chris Hemsworth—a superhero on TV and, to some degree, in real life. If he hurts and struggles to learn these lessons, maybe we will be a little kinder to ourselves and give ourselves the same space and credit to deal with life’s hard stuff, just as we watch Chris do.

It is a great way to make complicated issues more accessible, normal, and interesting. If you can find a way to be interested in your life, including your pain, you are much more likely to deal with it and even want to deal with it in the first place.

Limitless: Live Better Now streams Aug. 15 on Disney+ and Hulu and will air on National Geographic on Aug. 25.