The following is a transcript excerpt from Dr. Jordan Peterson’s conversation with physician and longevity expert Peter Attia about the benefits of exercise, even from just three hours a week. You can listen to or watch the full podcast episode on DailyWire+.
Start time: 04:07
Jordan Peterson: A long while back I was looking at interventions to improve people’s lives, and I knew at that point cognitive decline was a major problem, especially in terms of productivity and general competence. It is a pretty pronounced linear downhill trend on the fluid intelligence front from about the age of 25 forward, and that can decline precipitously in the late 70s and early 80s, especially with the onset of degenerative neurological diseases. I was looking at the literature on cognitive remediation. This was about 10 or 15 years ago when there were a lot of online sites that purported to run you through cognitive exercises that could increase or maintain your IQ. There has never been any evidence for that, by the way. It is pretty damn dismal literature. But what I did find, and I think this is extremely solid, is that if you want to maintain your cognitive function, both cardiovascular exercise and weight lifting seem to do a pretty damn good job. Maybe that is because the brain is such an oxygen demanding organ. It is energy demanding and resource demanding in other ways, and if you can keep yourself cardiovascularly fit, interestingly enough, that is the best pathway to cognitive health.
Then I looked on the psychological side and found there were interventions that helped people get their story straight. Of course, psychotherapy is one of those, but there are also written interventions. If people write about their past, about their past traumas, and if they write about their future plans, they reduce general uncertainty that reduces their stress, and that seems to produce a relatively pronounced physiological benefit. So there is an interesting interplay there in terms of the emotional and the physical. It is pretty funny that if you want to improve your cognitive function or maintain it, you should exercise rather than think, and if you want to improve your physiology, you should straighten out your story and face your traumas rather than, say, exercise.
What do you recommend in your book Outlive with regard to the expansion of health span? What do you think? And how do you practice this personally? What do you recommend to people?
Peter Attia: I think that exercise is empirically the most valuable tool we have for both the cognitive and physical components. So let’s start with the cognitive because I think it was less intuitive. So about 10 years ago when I really went down this rabbit hole, I had one of my research analysts spend a lot of time going through the literature, so we created a framework where we were going to look at every single intervention and how it impacted executive function, processing speed, short-term memory, and long-term memory. Those were the four metrics we cared about because, as you point out, those are all bits of intelligence that decline with age.
We looked at everything. We looked at every molecule. We looked at every possible thing that you could think of. And after about nine months of this, the thing that stood out above all else — beyond any diet, beyond the importance of sleep, and other things that certainly mattered, controlling blood pressure, lipids, et cetera — was exercise. And even though I was a lifelong exerciser and love to exercise, I just couldn’t believe it. It seemed so trite that exercise could have such a profound difference on the state of cognition, not just in terms of its performance as effectively a no trophic, but also in its ability to delay — if not outright prevent — dementia.
Once we dug into the mechanisms, I think it became clear why exercise is so potent, and it’s basically that it is acting on so many different levels. So as you pointed out, it’s acting at a metabolic level. The brain is such an energy demanding organ, as you know and maybe your listeners do, it weighs about 2% of your body weight and it’s responsible for 20 to 25% of your energy consumption. Therefore, anything that disrupts that is catastrophic. When you look at the improvements in glucose disposal, insulin sensitivity, and all metabolic parameters, exercise is the most important tool we have there. When you look at the reduction of inflammation, vascular health improvements, again, exercise stands alone. When you look at the production of neurotrophic growth factors such as BDNF, again, exercise is basically a drug for neurons.
I think I eventually came around after a year or so to realize that, again, as simple as it sounds, exercise is such a potent tool. And you look at the brains of people who exercise a lot and you can see far less damage, not just microvascularly, but in terms of brain volume lost over time.
Jordan Peterson: So let’s talk about exercise from the perspective of a behavioral psychologist. One of the things you learn as a behavioral psychologist is that it is very difficult for people to change their attitudes or their actions, and it is very difficult for people to change their lives. We all know this because we might tell ourselves, for example, to exercise, and we might be well supplied with arguments for why that is a good idea, but that does not necessarily mean we learn how to incorporate an exercise routine into our lives.
There are many reasons for that, one being that exercise is difficult, but it is also often the case that people do not form a strategy and break the problem down into steps that are simple enough to actually implement. They think things like, “Well, I’ll go to the gym two hours a day, three times a week, and I’ll start that next week.” The truth of the matter is they do not have six hours to spend, and they cannot tell themselves what to do anyway.
So as a behavioral psychologist, you look at the simplest possible change that produces the maximum possible benefit. For example, if people want to begin to implement an exercise routine, like maybe a daily walk of 10 minutes in the morning, where would you start someone?
Peter Attia: So it completely depends on their baseline. But based on your question, I’m going to take it as we’re talking about someone who’s doing no exercise. The good news is, first of all — and I accept the fact that not everybody is swayed by data, but I at least want to put it out there — if you’re a person who’s in the “doing zero exercise per week” camp, the very good news is the benefit you get from going from zero to three hours a week is a greater benefit than anyone gets along the exercise curve. So taking someone who’s at five hours and taking them to 15 will produce less relative benefit than going from zero to three. So in other words, I want that person to see some real incentive for making this change.
Secondly, I’ll put some numbers to it. So going from no exercise to three hours a week approximately reduces your all cause mortality — that is to say, death — by every cause by 50% at any moment in time. So if you’re standing there asking, what’s the probability I’m going to die this year? Well, we can sort of actuarially figure that out. You get to cut that number in half by simply going from zero to three hours of exercise a week if you’re a non-exerciser. So again, there’s going to be a subset of people for whom that’s a very powerful piece of information they didn’t know.
Then what I would say is, how do you do that? I agree with you that you’re much better off trying to do 30 minutes six times a week than three hours once a day or two hours, you know, in whatever fashion. What I would say is the most effective way to do that is probably about 90 minutes of low intensity cardio. And for a person who’s not particularly fit, that’s going to amount to just brisk walking. Rather than tell them what to do, I tell them how to feel when they’re doing it. So what you want to feel is out of breath enough that you can barely carry out a conversation, but you could if you had to, but not so out of breath that you can’t carry on a conversation and not so easy that you can speak easily. So there is that sweet spot in there. Physiologically, we call that zone two, but I’m not going to bore them with that nomenclature. It’s just basically 90 minutes to, say, three times 30 or two times 45 a week where you’re just out of breath enough that you don’t want to talk, but you could if you had to. That’s part one.
Jordan Peterson: So you push yourself past, or slightly past, your simple level of comfort. Then let me push on you a bit with regards to three hours a week, again, from the perspective of taking someone from zero to somewhere. You talked about the benefits of walking, something approximating 20 to 25 minutes a day, that can be dispersed out various ways. You also mentioned two 45-minute sessions or three 30-minute sessions. What would happen if someone goes from zero to like 10 minutes a day or an hour a week? Where do the benefits of that 3 hours kick in?
Peter Attia: Yes, that’s a great question. I don’t think we have the fidelity of the data at that level because you generally don’t push enough of a conditioning benefit. But I think what you’re getting at, and we do this as well, is you want to separate between the behavior change and the physiologic change. James Clear has written a lot about this, but I think a lot of people have come to the same conclusion with any behavior change. If it’s a person who’s never done anything, you’re right; the answer might be for every day when you wake up in the morning, rather than your normal routine of jumping in front of the computer, I want you to go and walk around the block once. It’ll take four minutes. I don’t want to represent [that] you’re going to get a physiologic benefit from that. You probably won’t.
But what you will get is, you’re going to start to reset a behavior which is, “Aha, the first thing I do in the morning now is this other thing,” and we’ll slowly increase that and at some point you will get a physiologic benefit. But what we’re doing is planting the seed of how to change the behavior.
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Dr. Jordan B. Peterson is a clinical psychologist and professor emeritus at the University of Toronto. From 1993 to 1998 he served as assistant and then associate professor of psychology at Harvard. He is the international bestselling author of Maps of Meaning, 12 Rules For Life, and Beyond Order. You can now listen to or watch his popular lectures on DailyWire+.