So how does one measure optimal versus accelerated aging? And why would it be that some stress is better than no stress when it comes to aging ideally? So having no stress means we're not really living, like we're not engaging in the gifts of life, which are inevitably have some challenge and risk.

And let me give you an example. One study took elderly people who have retired and they, you know, society kind of labels them as you're kind of done with your meaningful work in life and you are pretty much not able to contribute to society. I mean, there's so many negative stereotypes that people then kind of embody and then live.

And this program brought them to work in schools and tutor young at-risk students. And what happened to them is they went from feeling maybe safe and under-stressed to feeling challenged, but generative. They were feeling more purpose. They were feeling like they were growing and they were feeling like their day had more meaning.

They had more relationships. They had these caring relationships with the students. The students had all sorts of issues and troubles, drugs and maybe not having lunch, poverty. And so they felt the stress of that, but they also saw how much they could help with their support and their tutoring.

And in this study, they took images of the hippocampus and those who engaged in the program, particularly the men, actually had growth of their hippocampus during this program. So at any stage in life, we can be growing and challenging ourselves even in our much later years and growing our brain.

And you know more than anyone, what does that hippocampal growth mean for their wellbeing and their cognitive function? Yeah. It's interesting that hippocampus, of course, a brain area involved in formation and recall of memories, mostly formation of memories, is super interesting because it's so plastic. It's so amenable to the addition of new memories.

I think the most striking study to me is the one, and I should point out that most of the data say that the addition of new neurons is not the main reason for improvements in memory, but it is one of them. But Rusty Gage down at the Salk Institute did a study in the, I think the early 2000s where they took terminally ill people and these people agreed to have their bodies injected with a dye that would label new neurons.

And then after they died, their brains were processed and they didn't die from the dye injection by the way, folks, they died from other causes, they were terminally ill. And what they discovered was that even in terminally ill and some of these people were quite old, those people were still generating new neurons, especially in the context of still trying to learn and acquire new information.

So of course they're dead so they can't apply that information after that, but of course none of us can, right? None of the information that... But why not? Up to when you die, right? Absolutely. Absolutely. So one other example of this, my colleague Dave Almeida, he measures daily stressful events in huge national populations and a small percentage of people report no stressors.

And so you wonder like what's happening? Are they not engaging in life? Are they really not having stressors? It looks like they are, it's not just that they're not getting stressed by things, they're not really going out and doing much. And what he found is that their level of kind of memory and cognition, their cognitive health was significantly lower.

So you can imagine the hippocampal, you know, the lack of those neuroprogenitor cells, they're just not being stimulated. It's super interesting. I wasn't aware of that result. So I appreciate you sharing it. I almost have to wonder if it's like exercise where, you know, so many people, I think now everybody hopefully understands that exercise is going to lower blood pressure, reduce resting heart rate, improve musculoskeletal function and bone density, all that stuff.

But that if you took a snapshot of the bodily response during exercise, blood pressure is way, way up. Heart rate is way, way up. Stress hormones are way up. Cortisol is through the roof during a hard workout and immediately afterwards. And yet that sets in motion a series of adaptations that brings you to a better place most of the time.

So I wonder if stress is the same. Is there any evidence that short bouts of stress provided that they're managed well, meaning that we don't spend the next 24 or 48 hours ruminating on the stressor, but that we're able to move through the stressor and resolve it in some way, that that's actually beneficial for us because of the mobilization of energy stores and maybe even changing our threshold for reacting to stressors in the future?

That's a great question. And it's one that I have been chewing on for a while because we know as you said that physical stressors, when they're short and repeated, like high intensity interval training, they are promoting not just aerobic fitness, but stress fitness. People feel less rumination, less depression, less anxiety.

So they're kind of tuning up the nervous system. What about psychological stressors? And we know two things. So one is I do think that there is a level of engagement with moderate stressors that when we are used to them, we get fit and our stress resilience builds, meaning we're less threatened by them.

So let me go deep into that. Two people can approach the exact same stressor and one person is having a pretty overreactive stress response where they basically are feeling their survival is threatened. So it's high cortisol, high vasoconstriction, and blood pressure goes up equally in both. But the person who's feeling super threatened, either their survival or their social survival of their ego, their blood pressure went up because of the vasoconstriction.

The other person who is viewing the same stressor as I can do this, this is a great challenge and opportunity, I have what it takes. Those types of thoughts generate a different hemodynamic response, which is actually more cardiac output, so blood pressure is going up, but in this healthier way, more oxygenation to the brain, better problem solving, they're able to maintain this positive outlook.

So we've measured the threat challenge response in many lab studies and we know lots of things. So if you're having more of the challenge response, at the end of it, you're less inflamed. So just in the lab within an hour or two, we see that they didn't trigger all that pro-inflammatory response and their telomeres tend to be longer, which is a measure we can talk more about.

But basically, it looks like they have a slower speed of aging. That is super interesting. You call this a stress challenge response? So we could call this kind of a two, to be really simplistic, two types of psychological stress response, feeling threatened, like you're going to fail, you're embarrassed.

That social pain response, we know well, that feels terrible, but also that huge stress response when we feel it in our stomach, our heart is pounding. It's just an over-exaggerated response. That response biologically is different and the thoughts that go with it are different and we recover a lot slower.

And then there's the challenge response, which is more of that kind of activated, excited response. And the beauty is that there are lots of studies out there done by emotions and social psychologists that tilt people toward the challenge response. We can actually promote that challenge response. And so when you asked about like, is it good to have a repeated stress response?

Yes, if it's manageable, then we're kind of building the muscle of stress resilience. What are the sorts of things that people I can do in order, including me, I should say, can do in order to wage that challenge response? Is this purely based on mindset? Like instead of saying, why me?

Why this? Why now? I can't believe this is happening. Is it a mental pivot to, okay, this is a great opportunity for growth. I don't know how I'm going to manage this, but I'll manage this. You want to stop me. You got to kill me type of mindset. Is that the switch that then the body follows?

Because this is an interesting instance where most all the stress mitigation work that my lab does is focused on using the body to control the mind. But here we're talking about the mind controlling the body first and then the body following suit, which I find equally fascinating. So are there some specific mental scripts that people follow and are we all able to follow those scripts?

Yes. To some extent, we control the script. We can use that script to prepare ourselves going into a stressful situation and we can use it at any point during the stressor. So some of us are just wired to have a big threat response period. Maybe it's epigenetics we've inherited.

Maybe it's early trauma that has shaped us to have this exaggerated emotional response and yes, we and others have found that. Trauma sensitizes our emotional stress response so that we are feeling more threatened. But that's okay because that's the part we can't control and we just have to have a lot of self-compassion and awareness that okay, this is what I do.

My body reacts like this, but what happens next? That's when we can start to use those statements, self-comforting, self-compassion, distancing. There's all sorts of statements that allow us to then recover more quickly. So when we want to shift from a threatened response to a kind of challenge response, or I should say, are there any data that dictate whether or not we should keep those statements in our head, write them down, say them out loud?

I guess what I'm trying to do here is trying to get to a little bit more of the meat of the actionable since a lot of our listeners I think will be, as I am, very excited about the idea that a mere shift in our mentality about stress can give us the opposite outcome.

I mean, before you were talking about vasoconstriction and inflammation and all these bad things, to put it lightly, and then in the challenge response to stress, getting the exact opposite, more vasodilation, more resources used, and more positive effects on the brain and body. So if you can recall from the papers, if not, that's fine, but I'm just curious what those specific tools might be.

Every statement you said, Andrew, is good. It's a good one. The whole trick here is that people need to find the strength statements, the stress shields, I call them, that fit them, that feels right, and that they believe. And so I list a bunch of options in chapter three, which is called be the lion instead of the gazelle.

So the lion and gazelle are both high blood pressure, high stress, and the lion's chasing the gazelle, but the gazelle's having this total threat vasoconstriction response because she might die, lion might get dinner, right? So it's needing to mount the stress response because it's so excited to get the tasty dinner for the next few days.

And so the lion is having that challenge response. And so we can remind ourselves, be the lion. It's not that we're always lion or gazelle. We get to shape that. And so some of those statements are, well, let's say right when we're going into it, list your resources. Why have you ever dealt with any situation like this?

Remind yourself of past successes. Remind yourself of someone you can call or text or feel supported by. Remind yourself that this outcome is not going to affect your life in 10 years or five years. That's a distancing kind of perspective taking. So there's all these strategies, and you got to use what works for you.

Telling yourself, I got this. I can do it. I can get through it. I have what it takes. Those are all good shields. And another set is some of us feel really stressed out by stress. Like once we feel our heart racing, that leads to, oh no, this is bad for me.

And so rather than getting stressed by stress, we actually want to remind ourselves that this stress response is empowering. This is going to help me cope. My body is excited. My body is doing just what it should right now. So that reframing in studies by Wendy Mendez and others, my colleagues who do this reappraisal research, they have basically trained people to view stress as positive.

During the stressful situations in the lab, people do better. They perform better. They feel more positive emotion. They problem solve better. They recover more quickly. So pretty powerful stuff.