Jacob Goldstein
Jacob Goldstein spent more than a decade as co-host of the Planet Money podcast. He's also the author of the book Money: The True Story of a Made-Up Thing, which the New…
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Circadian rhythm isn’t just controlled by your brain. Every cell in your body runs on a 24-hour cycle, including your muscle cells.
Karyn Esser is the chair of the department of physiology and aging at the University of Florida, and she’s a leading expert on circadian rhythm in muscle cells. Karyn’s problem is this: How does the circadian rhythm in muscle cells change as we age, and how does exercise help keep our system in sync?
In this episode, Karyn explains:
- How every cell in your body has a clock in it
- How muscle clocks prepare cells for work and schedule recovery during rest
- How age affects these clocks’ ability to regulate effectively
- Why exercise can improve clock function
- Why jet lag and late-night eating can put your body clocks out of sync
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Pushkin Here's a thing I did not know until very recently. Every cell in your body has a 24-hour clock in it. In other words, your circadian rhythm is not just in your brain, it is everywhere in your body. And it doesn't just affect when you go to sleep and when you wake up. It affects metabolism. It affects repair of damaged cells. It affects the release of hormones. Your circadian rhythm affects all kinds of things that need to happen in your body to keep you healthy. Unfortunately, as you get older, the clocks in your cells stop regulating everything quite so well. The system gets disordered. Things fall apart. It's not all bad news, though. There are things you can do to slow the process of degradation. And scientists are learning more. They are figuring out how to keep the circadian rhythm in all your cells working better into old age so that you can stay healthier for longer. Music I'm Jacob Goldstein, and this is What's Your Problem? My guest today is Karen Esser. She's the chair of the Department of Physiology and Aging at the University of Florida, and she's a world expert on circadian rhythm in muscle cells. Karen's problem is this. What happens to the circadian rhythm in muscle cells as we age? And how can we keep the system from falling apart? Part of the answer seems to be exercise. Exercise helps keep the circadian system functioning better for longer. Now, in her research, Karen is trying to figure out why. What is going on exactly at the cellular level here? And the answer to that question could shed light on other ways to fight age-related decline. In our conversation, Karen and I discussed why muscle cells need a 24-hour clock, what the circadian rhythm in muscle cells means for when we should exercise, and Also, how your stomach and your brain can wind up in different time zones when you travel. And how Karen's research has led her to change her own habits. To start, Karen told me that she didn't set out to study circadian rhythm. She was actually looking at the effect of exercise on muscle cells. And she wound up studying circadian rhythm because of a finding that was so weird that at first she thought it was a mistake.
02:42
Speaker 2
We were looking at responses in muscle cells. in response to an exercise bout. And the clock genes came up. So that study, you know, 20 years ago was focused on that with no idea of circadian clock genes.
02:55
Speaker 1
But you found it surprising. You said, oh, after a bout of exercise, these cells are turning on genes that we associate with the sleep-wake cycle, with the circadian rhythm. And that was a surprise.
03:06
Speaker 2
Correct. But it's in the muscle. Yeah. What the heck?
03:08
Speaker 1
So, like, why does the muscle care what time it is? And.
03:11
Speaker 2
And really, is this just a technical problem? Did we make a mistake? And so, you know, as a PI, you always question your students first.
03:20
Speaker 1
You thought somebody screwed up. You're like, there's no way.
03:23
Speaker 2
No, no. And as usual, the students are fine and they did the right thing. It's just the biology is much more exciting. So that started my whole research trajectory in that. So that's a little side note.
03:35
Speaker 1
No, that's quite interesting. I mean, I think there's an idea here. Let me take a stab at it. You can tell me if it makes any sense or if I'm reaching. I feel like there's this interesting arc over the past, I don't know, few decades, I guess, of realizing that more is going on in each cell than we thought. You know, I feel like there's this old model where the brain is sort of all the action and then the body's just kind of dumb. The muscle just, you know, contracts and lifts things. But as we have looked closer, including the kind of research you're talking about, we've seen that, oh no, the cells themselves are talking to each other, are sort of Making what we might call decisions or, you know, adapting. And this seems like part of that, right? Like the fact that every cell has its own 24 hour clock is wild and really interesting.
04:21
Speaker 2
It is. It is. And I, you know, I'll be real honest. When I first started, I had some colleagues that were like, what the heck are you doing? You know? Because I had my line of research, I had NIH funding, and now I'm going over it.
04:33
Speaker 1
You mean when you started looking into circadian rhythms in muscle cells? Yeah, because they just said, oh, it's.
04:37
Speaker 2
Just noise, or, oh, it's really, the muscle clock doesn't matter, it's just a dumb clock downstream of the brain.
04:45
Speaker 1
Well, why didn't you listen? Why didn't you think that?
04:49
Speaker 2
Well, I don't know, the whole thing fascinated me. The idea that you have this clock that's an oscillator clock, regulating programs of gene expression in a cell. Yeah.
04:59
Speaker 1
And in a muscle cell, in a muscle cell, right? It's weird.
05:03
Speaker 2
Well, yes, yes. But again, I'm very influenced by evolution. Muscle cells are really.
05:09
Speaker 1
Old, okay? I mean, they're evolutionarily ancient, older than, say, eye cells or something like that.
05:16
Speaker 2
Or even a central nervous system, right? My whole training and kind of how I've thought about biology... has been more that muscle is part of this system. And so I think I was a little bit refractory to those people that were concerned about me. Yeah.
05:32
Speaker 1
I mean, the idea that muscles are sending signals to the body, right? That muscles are part of the endocrine system. Like they're not just there to move your arms and legs around. Right.
05:43
Speaker 2
Or look good when you're on the beach, right?
05:45
Speaker 1
Most importantly.
05:48
Speaker 2
So, right.
05:48
Speaker 1
So there is this broader... realization that, I mean, does every cell have a clock, have a 24-hour clock?
05:58
Speaker 2
Virtually all cells. I think it's pretty safe to say yes.
06:01
Speaker 1
And other organisms? Like, does everything, does bacteria have a circadian rhythm? It does.
06:08
Speaker 2
I mean, they do. But, you know, I think, you know, plants, bugs, insects, you know, when you look across, you know, Almost everything you're looking at is going to have a clock in it.
06:21
Speaker 1
And like every cell in everything.
06:23
Speaker 2
Yeah.
06:24
Speaker 1
What is the clock? Like we're saying there's a clock. It's not a clock. Like it's something where there's like a 24-hour cycle where things change over the course of 24 hours and they go back. But like what's going on?
06:36
Speaker 2
It's a great question. And as someone that sort of came into the field from physiology, it took me, you know, it took a little while to kind of wrap my head about how to think about this. So there is what we call the core clock. And that is what I call the timer. So that's that 24-hour timer. And so there is a process of gene expression. Then the proteins are made and the proteins come back in. And then they do their function. And this takes approximately 24 hours.
07:04
Speaker 1
Is the theory that mainly what it's doing is keeping time? Is there like a set of gene kind of expression and something happens and another gene is expressed and it takes 24 hours and that's its function?
07:14
Speaker 2
That's part of its function.
07:16
Speaker 1
Yeah. Like that is rad, right? Like that is such a wild evolutionary thing.
07:22
Speaker 2
Oh, it is awesome. And I mean, part of it is I just, like I said, I didn't train in this, but when I, the more I read about it, it was just like, holy, this is really cool. And, and, and it's what we call self-sustaining, which means it doesn't need a cue. You don't need light for it to work. You don't, it is intrinsic to that genetic network inside the nucleus of that cell. So it's frigging amazing. But it has another job, and this is important from a physiology, from an aging perspective, is that these core clock factors will also sit on lots of different places. So in muscle cells, they will sit on about 4,000 to 5,000 different places across the genome in a muscle, and they'll help contribute to what I call a daily program of gene expression. And so I think of it as a temporal organizer of housekeeping. And again, for a muscle cell, What you see before you wake up in your muscle cells would be genes that are important for metabolism, right? For oxidative metabolism.
08:24
Speaker 1
So this is like early morning, an hour before I get up at whatever, 6.30 every day. What's going on? Let's do a day. Can we do a day in a muscle cell?
08:32
Speaker 2
We can do a day.
08:33
Speaker 1
Okay. So it's 5.30 in the morning, an hour before I'm going to get up. If it's a good night, I sleep till 6.30. What's going on in my muscle cell at that time?
08:43
Speaker 2
So what the clock is doing at that time, so obviously your muscle cell is kind of hanging out, but the clock is regulating genes that are going to contribute to your ability to use carbohydrates and fats as fuel.
08:54
Speaker 1
So it's getting ready. It knows I'm going to get up. That's what's happening?
08:58
Speaker 2
Yeah, I think of it warming up the engine.
08:59
Speaker 1
I love it.
09:00
Speaker 2
The metabolic engine. So you get that warmed up because you don't want to start from cold.
09:04
Speaker 1
Okay.
09:05
Speaker 2
And so now you wake up and you're ready to go. And the things that are important so that, you know, your mitochondria are ready, all these things that are important for input or sensitivity to insulin or incoming glucose. They're already.
09:21
Speaker 1
So just to be clear, they're primed so that when I get up and I start using my muscles, whether it's just going downstairs to make breakfast or going for a jog, they're ready to take in sugar and make energy and do their work as muscles.
09:33
Speaker 2
Correct. Yes, exactly. So they're ready to do work because that's what muscles do. But they obviously need fuel for that.
09:42
Speaker 1
And then what happens over the course of the day? So now we're up. Is stuff changing all through the day?
09:49
Speaker 2
Absolutely. And so what you will see is that so as you start moving, as you start working, depending on how intense and that, some of your energy stores, like some of your... like glycogen, that will start declining.
10:02
Speaker 1
Yeah, which is basically stored sugar. Yeah, stored glucose.
10:05
Speaker 2
Right. So that's going to be highest in muscle at the start of the day. And then it'll start to get used as you do things. Yeah. And then you start moving into kind of the second half of the day. And it's, again, depending on your daily life patterns, then it's starting to prepare for the rest phase, which means what are you going to do during the rest phase? Well, you're going to start restoring glycogen. You're going to store other energy substrates. The way I think about it is, you know, you don't want to be repairing and replacing while you're using and contracting. I see. So you're going to send that to the rest phase. Recovery and maintenance gets done while you're in the shop, i.e. sleeping.
10:44
Speaker 1
Okay. So it's basically get ready to work, work, get ready to recover, recover.
10:52
Speaker 2
Correct.
10:53
Speaker 1
That's the basic cycle. Right. And so how does my exercise habit affect the circadian rhythm? Oh, my God.
11:05
Speaker 2
We don't have enough time for this one. Right. I'm sorry, because we're just learning some really exciting things right now. So this is a great topic.
11:13
Speaker 1
Okay.
11:14
Speaker 2
Because I also have this role within the Motorpack Consortium, which is.
11:19
Speaker 1
Love Motorpack. Molecular transducers of physical activity. Did I get it? I don't have it in front of me.
11:25
Speaker 2
Exactly. So what is it about exercise that makes us healthy?
11:28
Speaker 1
Let's just say what Motorpack is, because it's part of the reason I want to be doing these interviews, right? The big idea of like... We've known for a long time that exercise is really good for you, but we haven't really understood why at a kind of cellular level. And motor pack is this big study trying to figure that out, right?
11:47
Speaker 2
Right. And I was part of the preclinical arm of motor pack. So we worked with the animal stuff. And what I love, I will say is, you know, we studied 18 tissues in these animals. So we're looking at spleen. We're looking at small intestine, different parts of the brain. Not the usual suspects, the muscle, heart, you know, fat. So anyway, so we are currently working on a series of manuscripts to be submitted hopefully in the next six months. But, you know, in terms of the systemic effects of exercise and the way exercise or physical activity, if people don't even want to just move, the way that can communicate throughout your body to cells that you maybe didn't even realize, you know, cells in the lung, your immune cells, like I said, the spleen, The colon, the colon, you know, with training, the colon is changing as much as a muscle cell is. And so, you know, the health benefits are absolutely systemic.
12:42
Speaker 1
I'm glad to hear it. Tell me about what you're learning about the circadian rhythm in particular. And I mean, really what I'm asking, so you've talked about the kind of basic circadian rhythm. And so I'm curious, how does it change with age? And how does it change with exercise? And then what is the relationship of exercise and aging in the context of the circadian rhythm?
13:02
Speaker 2
Okay, so let's start with aging. So what we've done, again, this is all with preclinical work, but the limited clinical data with aging and circadian rhythms is very consistent. And that is the clock works as we get older. So the timer still works. So if you think about those two functions I talked about, which is the timer, and then we're going to call it the output of the clock, the output changes. And the output starts changing in middle age, unfortunately. So even though the clock's working, the types of genes it's regulating and when it's regulating those genes... Going back to your conversation with one of the other guests you had on was talking about autophagy or the ability of the cell to break down proteins. Well, at a young age in the muscle, genes involved in autophagy are under circadian control, and they are peaking just as we go into the rest phase, as we were talking about. Right.
14:00
Speaker 1
This is part of the sort of cleaning up the cells. Correct.
14:04
Speaker 2
By the time the animals are middle age, those genes involved in autophagy are now peaking toward the end of the rest phase. So now they're going to be coming on at a time you're going to want to be moving around. And so, you know, when I think about the clock, it's like you've disordered the sequence.
14:22
Speaker 1
It's not working as well. It's going to work, but.
14:25
Speaker 2
It's not going to work as well. The efficiency is going to be down and there are going to be more mistakes made. Yeah.
14:31
Speaker 1
Okay. Okay.
14:32
Speaker 2
And so then by the time you get to really old age, it's just, it's awful. It really is. When you're younger and even when you're middle age, there are categories of genes that are regulated across all 24 hours. By the time you get to, in the mouse muscle, by the time you get to old age, that gets lost. You get a peak of genes peaking around sort of rest to active phase transition. But that's it. And the overlap, So the genes that are what we call clock-controlled in the very old are not at all what you see in the younger animal, and they're not at all what you see in the middle age. So there's a loss of identity as well as a loss of timing.
15:17
Speaker 1
We'll be back in a minute with some good news. Tell me about exercise and circadian rhythms. You know, in the muscle, but throughout the body. Like, what does it do? How does it work?
15:37
Speaker 2
So, we're learning. So, again, I always, I don't want to.
15:40
Speaker 1
Well, tell me what's clear. Like, let's start with what's most clear and then move towards sort of the frontier of what you're figuring out.
15:47
Speaker 2
So, what we do know is that muscle contractions or exercise of the muscle absolutely talks with the clock system in the muscle. And so... What that means is, let's say I've been exercising in the afternoon and my work schedule changed, so now I'm going to have to exercise in the morning because of my job, right? So I'm going to start exercising in the morning. What will happen is the clocks in the muscles, it may not feel great at first, but the muscle clocks will sense the timing of exercise and they're going to shift. And in general, the way to think about it is, so if I was exercising in the afternoon, they're going to shift closer to align itself with when, you know, I am exercising in the morning. So that will happen. It doesn't require a change in the brain for that shift to happen.
16:34
Speaker 1
And so what is what's actually happening when that happens? It's sort of like they're storing energy. Like, what does that mean in practice, that shift?
16:43
Speaker 2
What we would predict is that, you know, so all the things I talked to you about, what happens to your muscle over time a day, All you're doing is shifting all those jobs to an earlier time. So you're going to prepare for your activity earlier and then the recovery will also be shifted in time. So you're going to just take your biology and shift it over.
17:02
Speaker 1
I mean, obviously, I know the main thing with exercise is just exercise. And like, I'm not really an optimizer. I just want to exercise every day. But, like, what is what you're saying about the circadian rhythm and your body adjusting if you usually exercise at a certain time? Like, what does that mean for how I should think about when I exercise if I have some control over when I exercise?
17:24
Speaker 2
So, I mean, this is a great question. What I would say is if you're thinking about performance, like, let's say you're going to be in a race or you're going to then you want to be exercising about the time you're going to be performing. So your system is I really don't believe in optimization, but it's best suited for that time.
17:45
Speaker 1
Yeah, if you want to run as fast as you can in your half marathon, then you should try and do your daily jog at the time the half marathon's going to be. Correct, correct.
17:52
Speaker 2
If you're, you know, exercising for health, that's more important than exactly when you exercise. And again, I also don't want to be too overly precise. You know, the clock is not, oh, you've got 15 minutes. If you don't exercise now, you're not going to capture it. No, it's not like that.
18:08
Speaker 1
So you've talked about aging and the circadian rhythm. And basically the circadian rhythm, just the clocks are not as effective at doing what they're supposed to do as you get older. And then exercise basically can adjust the clock. What effect does exercise have on aging in the context of circadian rhythm?
18:29
Speaker 2
So a junior faculty member in my lab has a study on that right now, and it's very exciting.
18:35
Speaker 1
So it's a secret? Can you tell me?
18:37
Speaker 2
Well, it's, you know, it's his work and I want to let him But it's good. It's very good. And so being more active improves the function of the clock and the clock output. And this was data looking at both muscle and liver. So the impact of exercise on the clock is system-wide. It's hippocampus, hypothalamus, cortex, spleen, small intestine, colon, muscle, heart, the usual suspects. But every organ in the body is responding to exercise in terms of their clock components. And so I am beginning to, well, I've been wondering about this, but I'm beginning to think about exercise as a clock improver with age. People are looking for small molecules. So there definitely are people out there looking to target the clock.
19:29
Speaker 1
Small molecules meaning drugs. Small molecules meaning drugs. Or nutraceuticals. Yeah, or supplements. Yeah. And so, I mean, as I understood it before, the problem isn't that the clock itself, it still keeps time just as well, but that it's like when the clock is telling other, well, genes basically, right, to turn on or off, that's the problem. part that gets less effective with age. Right.
19:52
Speaker 2
Correct.
19:52
Speaker 1
And so the intervention isn't to make the 24 hour thing work, keep time better. It's the relationship between the clock and all the genes it's turning on and off.
20:02
Speaker 2
Perfect. You've got it.
20:03
Speaker 1
Does it matter what time of day I exercise? Let's stipulate. Always it's better to exercise than to not exercise. And the important thing is to exercise. And, like, I'm not trying to win a race. Like, if I have some flexibility, does it matter?
20:16
Speaker 2
I don't think so.
20:18
Speaker 1
Is it better if I do it at the same time every day if I can't?
20:21
Speaker 2
That's what I'm going to come back to. I would say that, you know, so what we do know is what time you exercise can make things shift.
20:28
Speaker 1
Yeah.
20:28
Speaker 2
So probably what's not recommended is, you know— seven in the morning one day and seven at night the next day. And this is a new field, to be honest with you. And so based on what I understand with the clocks, with the clocks and exercise and health, I think just find a routine that works for you. When you're active, how you're active, if you're active, is going to be an important informing cue for the clocks across the body. And that's going to be important for health. And especially with age, one of the key issues with aging is a loss of resiliency. So you're exposed, you get a disease, the disease progresses either more quickly or more seriously, so you end up in the hospital. And it just leads to a bad sequence. And to me, this is something that addressing... clock robustness throughout the system is a way we can help.
21:27
Speaker 1
Why? Like what's the relationship between the circadian rhythm and, you know, getting more or less sick if you get an infection?
21:35
Speaker 2
So if I think of, you know, my cell and the ability of my cell and my cell's going to get immune challenges, it's going to get all these things. And you just think of it as this little island that has to resist outside warriors. And so the clock is a key part of the ability for that cell or that tissue or that human to maintain homeostasis.
21:55
Speaker 1
To stay healthy.
21:56
Speaker 2
To stay healthy. And so what that also means, and I will speak from my own aging perspective, is when you get older, it takes longer to recover.
22:06
Speaker 1
Yeah.
22:07
Speaker 2
But the better you can keep your clocks working, the more resilient your cells are going to be, the more able they are to recover and to be strong and resilient against external challenges.
22:21
Speaker 1
I mean, does this go back to the idea of like there's a time for resting and the time for resting is sort of rebuilding, cleaning up? doing these things that take energy and that we don't want to do when we're moving around because we need our energy for moving around. And when we're young, that just happens. And as we get older, that works worse, but exercising makes it work better. Is that the basic model?
22:42
Speaker 2
Yes, that's the basic model. Yep, exactly. I think identifying the experiments and the ways to demonstrate that very clearly and directly is sort of where I'm very interested right now.
22:56
Speaker 1
And does the kind of exercise matter in terms of.
22:59
Speaker 2
I don't think so.
23:00
Speaker 1
Yeah. Like resistance training, cardio, fast, you know, fast cardio, slow cardio, whatever, just do whatever and it's good?
23:08
Speaker 2
I think so. I mean, for the clocks, okay? I mean, obviously, if you want to grow muscle, that's versus.
23:14
Speaker 1
No, no, but for the clocks, yeah.
23:15
Speaker 2
For the clocks, I don't think it's going to matter.
23:18
Speaker 1
Great. I love that answer. Just do something. Don't do nothing.
23:22
Speaker 2
Something. Yes. Yes.
23:24
Speaker 1
You know, we got to talk about jet lag at some point. I'm talking here to an expert in circadian rhythm. How could I not ask you about jet lag? So what should I know about jet lag? Tell me about jet lag.
23:35
Speaker 2
So what is jet lag? Jet lag is when you travel to. So let's say I go from Gainesville, Florida, to Paris, France. It's a six hour difference. And jet lag, you feel crummy.
23:46
Speaker 1
Not great. Right.
23:47
Speaker 2
Right. That's a circadian syndrome. Yeah. Because all the clocks in your body get disrupted by that change in light cycle and that time cycle, and you feel crummy while things are out of alignment.
23:59
Speaker 1
Okay?
24:00
Speaker 2
Until they all get aligned.
24:02
Speaker 1
Well, and so there's two kinds of alignment, right? The sort of vernacular alignment, the one I think of is, oh, my body thinks it's whatever. six at night, but it's actually midnight. But there's another kind of alignment given that we have clocks in all of our different cells. Like when you get jet lag, do your different cells wind up thinking it's a different time within your body?
24:26
Speaker 2
Yes. Different cells in your body adjust to the new time at different rates. So you're going to be in that period of blah. Yeah. your brain's going to adjust pretty fast with the light cue. But the rest of the cells, like your stomach and do you feel hungry or, you know, whatever, I mean, they take different periods of time to adjust.
24:46
Speaker 1
So even just like shifting when you sleep to, you know, whatever, I'm going to go to sleep in the middle of the night and wake up in the morning, you're still not going to feel good because your body is going to be internally inconsistent. Your stomach's going to think it's one time and your brain's going to think it's another.
25:01
Speaker 2
Yeah, exactly. So when I think about alignment, I'm talking about the alignment of the clocks in my brain, you know, heart, throughout the body. And what we now know, there's a term called social jet lag.
25:14
Speaker 1
Okay.
25:15
Speaker 2
And you can feel as bad as you do with jet lag just by staying at home, having a normal light cycle, but let's say late night eating. Because what late night eating is going to do, it's going to tell clocks in your peripheral tissues that it's really maybe midday.
25:29
Speaker 1
Uh-huh.
25:31
Speaker 2
But your brain's like, no, it's nighttime. And so there is a misalignment of clocks throughout the body. And you just, I mean, again, it's not lethal, but you don't feel great.
25:45
Speaker 1
We'll be back in a minute with The Lightning Round. The Lightning Round I want to do just a lightning round. What is one thing a lot of people get wrong about fitness and aging?
26:07
Speaker 2
That there's, you know, if you get to a certain age and you've never worked out, it's not going to do you any good. There's lots of data. This is, you know, yes, you can. And yes, it does. Will it do everything it would have done when you were 20 or 30? Maybe not, but it still has health benefits for sure.
26:24
Speaker 1
Well, and going from nothing to a little bit is a huge gain, right? Like people who don't move at all, if they walk for 10 minutes a day, like literally you see these very large benefits.
26:36
Speaker 2
Exactly.
26:38
Speaker 1
Tell me about caffeine. We didn't talk about caffeine.
26:41
Speaker 2
Yeah, so caffeine basically stimulates the autonomic nervous system, epinephrine, norepinephrine. Some of the clock genes can be sensitive to this, but I think there's no really strong evidence that the coffee is going to modify the clock.
26:59
Speaker 1
Has your research changed how you exercise?
27:02
Speaker 2
It's changed how I live my life.
27:05
Speaker 1
Say more.
27:06
Speaker 2
Yeah. Well, I am older, too. But I've always been an early morning person. So that hasn't changed so much. But thinking about, you know, when do I start eating? When do I stop eating? Sort of the time-restricted aspect with that being a cue. Light exposure at night.
27:25
Speaker 1
When do you stop eating, if I might ask?
27:27
Speaker 2
I target for like 7 o'clock. Yeah. But, you know, 7 to 8.
27:32
Speaker 1
One tip for dealing with jet lag.
27:34
Speaker 2
Get out and walk around. Or if you want to swim, swim. Do something. And wherever you are, just get into sync with that day as quickly as possible. But movement and time you're eating to be in cycle, just, you know, don't go to bed right away just because you've been up all night.
27:50
Speaker 1
Should we make daylight saving time permanent? Stop changing the clocks. No. Oh, God, no. Oh, interesting. I thought you were going to go the other way.
27:59
Speaker 2
Standard time should be permanent. Oh, okay.
28:00
Speaker 1
Okay. So we should stop changing the clocks, but it should be standard time, not daylight saving time. Correct. Daylight saving is when you spring forward, right? Correct. So you set the clocks forward, so it means six becomes seven. So it gets light later in the morning. It stays dark until a later time in the morning, and then it stays light later in the evening. Late at night, right. That's bad, you're saying.
28:21
Speaker 2
Correct, for a couple of different reasons. One of them is when you think, and the one that's argued most is child safety, going to school in the morning, especially as So if you kept that the same all the.
28:31
Speaker 1
Time, kids would go to school in the dark and that's.
28:34
Speaker 2
Completely in the dark. Right. And then there are there are sets of data out there that, you know, so standards time is based kind of in intrinsic time of day sunlight cycles. Right. And and there's some data that that in terms of the biology with people living on more standard time versus on daylight savings time.
28:57
Speaker 1
Is it right the bill that's in Congress now is for permanent daylight saving time as opposed to permanent standard time?
29:02
Speaker 2
Correct.
29:03
Speaker 1
Why?
29:04
Speaker 2
Well, it's because, well, I mean, where am I, Florida? So the Society for Research on Biological Rhythms is the main scientific organization, has had policy statements out for several years on this. We've talked to our senators, we've talked to our congresspeople, but it likely is Golf courses, places where people, I don't know whether it's the theme parks too in Florida.
29:32
Speaker 1
Places where people go, say, after work if it's still light. Correct.
29:37
Speaker 2
So it's an economic issue, right? Instead of a health and safety issue.
29:43
Speaker 1
Thank you for your time. It was delightful to talk with you.
29:46
Speaker 2
Oh, sure. That was so much fun.
29:54
Speaker 1
Karen Esser is the chair of the Department of Physiology and Aging at the University of Florida. Today's show was produced by Gabriel Hunter Chang, engineered by Sarah Bruguier, and our showrunner and editor is Jake Harper. I'm Jacob Goldstein.
The Host
