WEBVTT - Fan Favorite: Is Exercising to Lose Weight a Myth? 0:00:02.560 --> 0:00:05.080 Guess what, Mango, what's that? Will do? You remember back 0:00:05.080 --> 0:00:07.120 in two thousand and eight when Michael Phelps had that 0:00:07.240 --> 0:00:09.600 daily diet that got so much attention because he was 0:00:09.640 --> 0:00:12.360 eating these insane amounts of food. Yeah, he was eating 0:00:12.400 --> 0:00:15.200 something like eight thousand calories a day. You try twelve 0:00:15.240 --> 0:00:17.680 thousand cowers a day during his peak training, he need 0:00:17.720 --> 0:00:21.560 a whole pizza, pound of pasta, three fried eggs, French toast, 0:00:21.640 --> 0:00:24.560 multiple burgers, and it seemed like anything else he could 0:00:24.560 --> 0:00:27.440 get his hands on, which seems so gross but also 0:00:27.680 --> 0:00:31.360 kind of the best thing ever. And during those same Olympics, 0:00:31.440 --> 0:00:35.280 Hussein Bolt reportedly ate forty seven thousand calories worth of 0:00:35.360 --> 0:00:40.000 chicken McNuggets. Yeah, he was eating them with fries for breakfast, lunch, 0:00:40.240 --> 0:00:44.199 and dinner. That seems at less great. Yeah, but wouldn't 0:00:44.240 --> 0:00:47.040 sixteen year old Mango think of it's pretty incredible. So 0:00:47.080 --> 0:00:49.279 I started thinking about this, and I know you've been 0:00:49.280 --> 0:00:51.239 getting back into the tennis, and I've been running a 0:00:51.240 --> 0:00:53.920 good bet these past few years. But I thought, if 0:00:53.960 --> 0:00:56.120 I could just take this to the extreme, I may 0:00:56.120 --> 0:00:58.959 be able to follow a similar diet. Like let's say 0:00:59.000 --> 0:01:01.240 I'm running twenty miles a week, right, now, and I 0:01:01.320 --> 0:01:04.440 just keep doubling that for the next five weeks, I'd 0:01:04.480 --> 0:01:07.160 be running six hundred and forty miles a week by 0:01:07.200 --> 0:01:09.440 the end of this. I'm so excited about this. Then 0:01:09.480 --> 0:01:12.360 I could eat like twelve Chipotle burritos every day and 0:01:12.440 --> 0:01:15.040 still have room for a half dozen Wendy Spicy Chicken 0:01:15.080 --> 0:01:17.880 sandwiches and maybe even a couple of those naked chicken 0:01:17.920 --> 0:01:20.520 choloopas after I run for the border. It's gonna be great. 0:01:21.200 --> 0:01:24.280 But after our research for today's episodes, Science may have 0:01:24.360 --> 0:01:27.720 crushed my dreams again. It turns out there's not quite 0:01:27.760 --> 0:01:30.480 as strong of a connection between exercise and weight loss 0:01:30.520 --> 0:01:32.960 as we once thought. So that's what we're gonna talk 0:01:33.000 --> 0:01:58.160 about today, Stupid Science Day their podcast listeners, Welcome to 0:01:58.200 --> 0:02:00.600 Part Time Genius. I'm Will Pearson and as always I'm 0:02:00.680 --> 0:02:03.520 joined by my good friend Manes Ticketer, and today we're 0:02:03.520 --> 0:02:07.640 diving into the topic of exercise, its benefits, it's limitations, 0:02:08.120 --> 0:02:10.520 whether it can actually help us shed some unwanted pounds, 0:02:10.680 --> 0:02:13.800 and if it really makes us healthier people. And fear not, 0:02:13.960 --> 0:02:16.520 we also have a couple of our patented, ridiculous quizzes 0:02:16.560 --> 0:02:18.799 along the way. Who've we got on the line today, Mango. 0:02:18.880 --> 0:02:21.800 So we'll be talking to Herman Pontzer, and anthropology professor 0:02:21.800 --> 0:02:24.720 at Hunter College in New York City. He's responsible for 0:02:24.800 --> 0:02:28.080 some truly incredible research on exercise, and he's gonna help 0:02:28.160 --> 0:02:30.240 us get to the bottom of just how useful physical 0:02:30.280 --> 0:02:33.360 activity really is for burning calories. We're also going to 0:02:33.400 --> 0:02:35.600 talk to a couple of personal trainers and see if 0:02:35.600 --> 0:02:37.320 we can whip them into shape through the power of 0:02:37.320 --> 0:02:41.320 our trivia. Right, So, before today's episode, I would have 0:02:41.320 --> 0:02:43.800 told you that exercising is probably the best way to 0:02:43.840 --> 0:02:47.000 lose weight simply based on the conventional wisdom of calories in, 0:02:47.200 --> 0:02:50.359 calories out. I mean that sounds sensible, right, Sure, We're 0:02:50.360 --> 0:02:52.760 taken calories through what we eat and drink and then 0:02:52.840 --> 0:02:55.640 burn them up through exercise. The more you exercise, the 0:02:55.680 --> 0:02:58.120 more calories you burn, and the more weight you lose. 0:02:58.320 --> 0:03:00.959 It just makes sense, it does. But there are actually 0:03:01.000 --> 0:03:03.120 all these studies conducted over the last few years that 0:03:03.200 --> 0:03:06.760 suggests exercise really isn't an effective way to lose excess weight. 0:03:07.200 --> 0:03:10.400 For example, Dr Timothy Church at the Pennington Biomedical Research 0:03:10.440 --> 0:03:13.119 Center at l s U. He held an experiment where 0:03:13.200 --> 0:03:16.639 hundreds of overweight women were given strict workout regiments for 0:03:16.680 --> 0:03:19.720 six months. The one group of them exercised a little 0:03:19.720 --> 0:03:22.160 over an hour each week, another one for a little 0:03:22.160 --> 0:03:25.799 over two hours, and another for over three hours. There 0:03:25.880 --> 0:03:27.960 was also a fourth group that stuck to their typical 0:03:28.080 --> 0:03:31.720 routine and didn't exercise at all. And against all logic 0:03:31.760 --> 0:03:34.200 and fairness, there was no major difference in the weight 0:03:34.240 --> 0:03:36.680 loss between the women who had exercised and the ones 0:03:36.720 --> 0:03:38.360 who had And how pissed would you be if you 0:03:38.400 --> 0:03:41.120 were that three hour group. In fact, some of the 0:03:41.160 --> 0:03:44.600 women in the exercise groups actually gained weight, which doesn't 0:03:44.640 --> 0:03:47.360 seem fair at all. I mean, they put into work, 0:03:47.400 --> 0:03:49.840 they deserve a reward. Well, it's funny you should say that, 0:03:49.920 --> 0:03:53.720 because Church actually concluded that the rewards were the problem. 0:03:53.760 --> 0:03:56.760 You know, exercise stimulates appetite, and many of the women 0:03:56.800 --> 0:04:00.640 counteracted their work by over eating afterward. Church suggested that 0:04:00.640 --> 0:04:02.560 it was justified in their minds. Is kind of a 0:04:02.640 --> 0:04:06.120 self reward for all the energy that exerted through exercise. Yeah, 0:04:06.160 --> 0:04:07.880 we hear that sort of thinking all the time, like 0:04:08.040 --> 0:04:10.800 cheat days and junk food rewards for going to the gym. 0:04:10.960 --> 0:04:14.280 But if we're canceling out the calories we burn, then 0:04:14.280 --> 0:04:17.520 we're probably imagining our workouts to be much more effective 0:04:17.560 --> 0:04:20.080 than they really are. I mean, the Department of Health 0:04:20.080 --> 0:04:23.000 and Human Services recommends people aim for at least thirty 0:04:23.000 --> 0:04:26.039 minutes of physical activity every day, but at thirty minute 0:04:26.080 --> 0:04:29.360 workout that only burns about two hundred calories, and the 0:04:29.440 --> 0:04:32.800 average slice of pizza contains close to like three hundred calories. 0:04:33.120 --> 0:04:35.200 So you can see how the map doesn't quite work. 0:04:35.360 --> 0:04:38.800 It's really just not fair at all. But it isn't 0:04:38.800 --> 0:04:42.600 just those powerful post workout indulgences that counteract calories burned 0:04:42.640 --> 0:04:45.760 through exercise. You know, the things we consume in preparation 0:04:45.880 --> 0:04:48.880 for even during a workout can also take a toll, 0:04:49.080 --> 0:04:51.200 which is a good point. I mean, those two hundred 0:04:51.200 --> 0:04:53.680 calories you burned during your thirty minutes on the treadmill, 0:04:54.040 --> 0:04:56.400 every single one goes right back into your body thanks 0:04:56.400 --> 0:04:58.960 to that bottle of gatorade or that energy bar you 0:04:59.000 --> 0:05:01.560 might have scarfed down while running right right, And the 0:05:01.600 --> 0:05:03.719 same goes for the bagel or the oatmeal used to 0:05:03.760 --> 0:05:06.839 carbo load before your workout, And we think the energy 0:05:06.880 --> 0:05:09.040 from these meals is going to help us power through 0:05:09.200 --> 0:05:11.880 and burn more calories at the gym, But it's actually 0:05:11.920 --> 0:05:14.279 the calories from those pregame foods that are going to 0:05:14.320 --> 0:05:16.840 get burned off first. And why is that Well, because 0:05:16.839 --> 0:05:19.640 sugar from what you've just consumed will still be floating 0:05:19.680 --> 0:05:23.120 freely in your bloodstream, and it takes muscle tissue much 0:05:23.200 --> 0:05:25.440 less energy to take that sugar than it does to 0:05:25.480 --> 0:05:28.720 burn off the existing fat stores. So your most recent 0:05:28.800 --> 0:05:31.480 meal will always be the first to go during a workout. 0:05:31.680 --> 0:05:34.160 But we can always just exercise a little longer, right, 0:05:34.200 --> 0:05:37.599 I mean, once those preliminary calories are gone, our muscle 0:05:37.640 --> 0:05:40.480 cells will start chipping away at storage fat for fuel. Well, 0:05:40.520 --> 0:05:43.400 I mean yes and no. According to some breakthrough research 0:05:43.440 --> 0:05:45.840 from Herman Ponzer, there are a lot of assumptions we've 0:05:45.880 --> 0:05:49.240 been making about human metabolism that they're not quite right. 0:05:49.360 --> 0:05:52.039 So you know, it's true that a longer workout would 0:05:52.080 --> 0:05:55.599 result in more calories burned and even some from storage fat. 0:05:56.240 --> 0:05:58.279 But we know there's a limit to how many calories 0:05:58.320 --> 0:06:00.719 your body will metabolize in any gift and day, So 0:06:00.920 --> 0:06:03.760 I'm definitely intrigued. But before we get too far into this, 0:06:03.880 --> 0:06:07.760 we should probably clarify the basics of metabolism, all right, well, 0:06:07.760 --> 0:06:11.760 I'll let you do that. Go for it, okay. So 0:06:12.480 --> 0:06:15.719 metabolism is basically the sum of all the processes that 0:06:15.760 --> 0:06:19.960 takes place in our bodies. We're talking digestion, respiration, the 0:06:20.000 --> 0:06:23.359 production of cells, the movement of substances between cells, you 0:06:23.440 --> 0:06:27.080 name it, and all these processes require energy, which our 0:06:27.120 --> 0:06:30.800 bodies released from the calories we consume. So even without 0:06:30.839 --> 0:06:34.359 exercise and other forms of physical activity, we still burned 0:06:34.440 --> 0:06:38.120 through or metabolize a huge number of calories simply by 0:06:38.160 --> 0:06:41.560 being alive. Yeah, exactly. So back to Herman Ponsers World 0:06:41.640 --> 0:06:46.080 Shattering Research and February's issue of Scientific American, Herman shared 0:06:46.120 --> 0:06:49.720 findings from his study of the Hadza tribe and rule Tanzania. 0:06:49.880 --> 0:06:52.440 He and other researchers spent a whole month living with 0:06:52.480 --> 0:06:55.200 the Hatsa, who were one of the last traditional hunter 0:06:55.200 --> 0:06:58.400 gatherer cultures left on earth. That was during this time 0:06:58.400 --> 0:07:01.200 that Herman and his partners recorded measurements of the daily 0:07:01.320 --> 0:07:05.080 energy expenditures of a couple dozen tribesmen and women. So 0:07:05.160 --> 0:07:07.520 this allowed them to compare the daily calorie burn of 0:07:07.520 --> 0:07:10.440 a society in which every member is highly active to 0:07:10.520 --> 0:07:12.960 a Western society like our own, and which members are 0:07:12.960 --> 0:07:17.080 more you know, sedentary. Well, back up a second. You 0:07:17.080 --> 0:07:21.040 said the researchers measured the hadzas daily energy expenditure, But 0:07:21.080 --> 0:07:23.760 I'm wondering how they pull that off. Are you really 0:07:23.800 --> 0:07:25.840 wondering that mango or are you just sensing there's an 0:07:25.840 --> 0:07:30.200 opportunity here to talk about doubly labeled water? Of course 0:07:30.240 --> 0:07:32.320 it is, you know, I love the d l W. 0:07:33.360 --> 0:07:36.360 Doubly Labeled water is the special water in which the 0:07:36.480 --> 0:07:40.640 hydrogen and oxygen molecules have been either partly or entirely 0:07:40.680 --> 0:07:43.880 replaced with heavy isotopes that aren't usually found in the 0:07:43.960 --> 0:07:47.200 human body. And it's safe to drink this stuff completely. 0:07:47.520 --> 0:07:51.160 They're stable isotopes, so they're non radioactive. But here's what's 0:07:51.160 --> 0:07:54.160 great about them. After somebody drinks d l W that's 0:07:54.160 --> 0:07:58.480 been enriched, researchers suddenly have this tracking mechanism. Basically, by 0:07:58.520 --> 0:08:02.360 measuring the concentration found in urine samples, researchers can determine 0:08:02.360 --> 0:08:05.880 a person's daily rate of carbon dioxide production. And since 0:08:05.920 --> 0:08:08.800 carbon dioxide is a waste product of our bodies energy 0:08:08.840 --> 0:08:12.560 making processes, calculating how much C O two someone produces 0:08:12.560 --> 0:08:14.880 in a day is the best way to measure their 0:08:15.000 --> 0:08:18.760 energy expenditure. That is pretty neat. Yeah, Doubly labeled water 0:08:18.840 --> 0:08:21.600 has become the gold standard for measuring how much energy 0:08:21.640 --> 0:08:25.520 a person consumes. Like, the margin of error is pretty small, 0:08:25.840 --> 0:08:28.360 and in fact, the only downside is the cost. D 0:08:28.560 --> 0:08:32.199 LW is expensive, Like are we talking smart water expensive 0:08:32.400 --> 0:08:35.439 or like Fiji water expensive? No, it's so much more 0:08:35.480 --> 0:08:40.959 than that. Dl W runs researchers about dollars per test subjects. Actually, 0:08:41.000 --> 0:08:43.640 you know what this really expensive water reminds me of? 0:08:43.760 --> 0:08:46.000 And I know that this is totally off topic, but 0:08:46.440 --> 0:08:48.439 did you know that the federal government actually sells a 0:08:48.520 --> 0:08:53.199 two jar of peanut butter and there's just six ounces 0:08:53.200 --> 0:08:55.440 of peanut butter in there. It's like a tiny jar. 0:08:56.040 --> 0:08:58.800 And it also goes by this incredibly catchy name. Are 0:08:58.840 --> 0:09:02.640 you ready for it? Standard Reference Material number two three 0:09:02.679 --> 0:09:05.760 eight of it? Oh? That sounds delicious, But why is 0:09:05.760 --> 0:09:08.600 it actually so expensive? Is it more delicious? No, it's 0:09:08.640 --> 0:09:12.240 the wonkiest reason ever. It's the super precise like peanut butter, 0:09:12.360 --> 0:09:16.600 with specific levels of amino acids and fats and carcinogens. 0:09:16.679 --> 0:09:19.719 And it's mostly used for quality controls so companies can 0:09:19.760 --> 0:09:22.800 test their standards against the governments and make sure it 0:09:22.840 --> 0:09:26.079 measures up. But as a result, no one actually eats 0:09:26.080 --> 0:09:29.120 the peanut butter. It's just for lad purposes, which only 0:09:29.120 --> 0:09:31.160 makes me want to try it more like with a 0:09:31.280 --> 0:09:35.319 really cheap jelly. All right, well, let's get back to D. L. W. 0:09:35.480 --> 0:09:37.280 Let me tell you what herman and his partners were 0:09:37.320 --> 0:09:39.559 actually able to learn from having the Hods of tribe 0:09:39.600 --> 0:09:41.960 drink it. Lay it on me. Well, first, let me 0:09:42.000 --> 0:09:44.200 preface this by saying that the Hods are the kings 0:09:44.240 --> 0:09:47.840 and queens of exercise. Every single day, the men trek 0:09:47.960 --> 0:09:50.520 miles and miles to hunt for game with homemade bows 0:09:50.559 --> 0:09:53.840 and arrows. They scale forty foot trees to hack tree 0:09:53.880 --> 0:09:57.160 limbs with hatchets and gather wild honey. Now, the women 0:09:57.240 --> 0:09:59.959 forage all day for wild berries and other edible plants 0:10:00.120 --> 0:10:02.680 like tubers that they dig out of the ground with sticks. 0:10:03.280 --> 0:10:05.360 Even the kids of the tribe are put to work 0:10:05.360 --> 0:10:09.120 by hauling pails of water from a mile or more away. Okay, 0:10:09.160 --> 0:10:12.400 so they're seriously active and no one sitting at their desks, right, 0:10:12.480 --> 0:10:14.880 definitely not. But what the researchers found was that even 0:10:14.880 --> 0:10:18.160 though the Hadzas lives are far more physically demanding. The 0:10:18.200 --> 0:10:20.440 amount of calories day ate and burned through in the 0:10:20.520 --> 0:10:23.640 day was the same as in Europe and the US. Now, 0:10:23.640 --> 0:10:26.439 the men went through about twenty six hundred calories a 0:10:26.559 --> 0:10:30.040 day and the women burned through about nineteen hundred. According 0:10:30.080 --> 0:10:32.760 to Herman, we looked at the data every way imaginable, 0:10:32.800 --> 0:10:36.199 accounting for the effects of body size, fat percentage, age, 0:10:36.280 --> 0:10:39.920 and sex. No difference at all, which is insane, isn't it. 0:10:39.920 --> 0:10:42.880 I mean that you naturally assume that physically active people 0:10:42.920 --> 0:10:45.959 would burn more calories, of course, but the research really 0:10:45.960 --> 0:10:48.400 doesn't bear that out. In fact, they did a follow 0:10:48.480 --> 0:10:51.240 up study with about three hundred participants and it showed 0:10:51.240 --> 0:10:54.079 the exact same thing. The people who were the most 0:10:54.120 --> 0:10:56.800 active burned the same daily amount of calories as those 0:10:56.800 --> 0:11:00.439 who were only moderately active, and the participants who barely 0:11:00.480 --> 0:11:03.280 left the couch at all burned about two fewer calories 0:11:03.280 --> 0:11:05.560 than them, the same amount they would have burned from 0:11:05.559 --> 0:11:08.600 a mere thirty minutes of exercise. Doesn't seem to suggest 0:11:08.640 --> 0:11:12.360 that our metabolisms are like fixed like. It almost seems 0:11:12.400 --> 0:11:14.720 like there's a preset amount of calories that your body 0:11:14.800 --> 0:11:17.719 is willing to burn in any given day. And no 0:11:17.760 --> 0:11:20.360 matter how far you run or how many push ups 0:11:20.400 --> 0:11:22.680 you do, you won't be able to top that max limit. 0:11:23.200 --> 0:11:26.360 But my bigger question is this, why doesn't the Hadza 0:11:26.480 --> 0:11:29.360 hunter burn more in a day than the average office worker. Well, 0:11:29.400 --> 0:11:31.680 I'm not sure we really have the answer to that yet, 0:11:31.720 --> 0:11:34.520 but one thing I've seen researches suggest is that our 0:11:34.520 --> 0:11:37.680 bodies account for the calories burned through physical activity by 0:11:37.760 --> 0:11:40.400 dialing back on the number of calories we devote to 0:11:40.440 --> 0:11:45.120 the background functions that keep us alive. About six of 0:11:45.120 --> 0:11:48.440 the calories we burn each day go to these unseen 0:11:48.640 --> 0:11:52.280 or unconscious processes, so it's possible that when our physical 0:11:52.280 --> 0:11:57.040 activity pushes us beyond that other of daily cloric expenditure, 0:11:57.520 --> 0:11:59.680 our body is just cut back on the calorie spin 0:11:59.720 --> 0:12:02.920 on tobolic processes. This would help even the scales and 0:12:03.000 --> 0:12:05.800 keep us from exceeding our preset energy budget for the day, 0:12:05.920 --> 0:12:10.000 which is really cool but also disheartening. Right, no wonder, 0:12:10.040 --> 0:12:13.959 I've got this paunch. I feel so betrayed. Don't take 0:12:14.000 --> 0:12:17.280 it too hard. So a fixed daily energy expenditure limit 0:12:17.400 --> 0:12:20.000 is likely, and evolved trade meant to help conserve our 0:12:20.040 --> 0:12:23.040 fat stores for when we really need them. I mean, 0:12:23.080 --> 0:12:25.400 imagine if the Hotsa hunters were free to burn through 0:12:25.440 --> 0:12:28.120 ten thousand calories during a hunt instead of the typical 0:12:28.160 --> 0:12:30.520 two thousand or so, if they were to come up 0:12:30.520 --> 0:12:33.120 empty handed, they would have lost five days worth of 0:12:33.200 --> 0:12:37.200 calories in one with no prospects for replacing them. And 0:12:37.240 --> 0:12:39.560 at that rate they're already limited. Fat stores will be 0:12:39.600 --> 0:12:41.840 depleted in no time, and they'd find themselves on the 0:12:41.840 --> 0:12:44.720 brink of starvation. Which is a great point, but still 0:12:44.880 --> 0:12:47.199 doesn't make you feel like maybe all that time spent 0:12:47.280 --> 0:12:50.040 exercising was I don't know, kind of a waste. Want 0:12:50.080 --> 0:12:52.840 no hold on a second, So don't forget that exercise 0:12:52.880 --> 0:12:56.080 has all kinds of great benefits beyond weight loss. For starters, 0:12:56.120 --> 0:12:59.680 exercises fantastic for your heart and blood vessels. It makes 0:12:59.679 --> 0:13:03.559 your heart contract with greater force and frequency, which increases 0:13:03.559 --> 0:13:06.920 blood flow leads to less artery clogging. There's also plenty 0:13:06.960 --> 0:13:09.920 of evidence that exercise helps reduce the risk of some cancers, 0:13:09.920 --> 0:13:13.640 as well as type two diabetes and cardiovascular disease. But 0:13:13.679 --> 0:13:16.760 one of my favorite benefits of exercise that often goes overlooked. 0:13:17.120 --> 0:13:19.480 Not only does it help strengthen your muscles, it helps 0:13:19.480 --> 0:13:23.160 strengthen your bones too. Just like muscles, bones grow stronger 0:13:23.160 --> 0:13:25.440 when they've been made to carry more weight than normal. 0:13:25.800 --> 0:13:28.839 So your muscles contract during exercise, they apply force to 0:13:28.920 --> 0:13:31.800 the bones that support those parts of the body. The 0:13:31.880 --> 0:13:34.679 added force stimulates the bones and causes them to reinforce 0:13:34.720 --> 0:13:37.480 themselves by building new tissue, which is really cool. But 0:13:37.600 --> 0:13:40.000 you know, Will, I'm pretty sure we'd have to forfeit 0:13:40.040 --> 0:13:42.400 our part time Genius membership cards if we miss the 0:13:42.440 --> 0:13:44.760 chance to talk about some of the more amazing mental 0:13:44.800 --> 0:13:49.040 benefits of exercise, like thanks to Fernando Gomez Pinia, a 0:13:49.160 --> 0:13:51.800 neuro surgery professor at U c l A, we now 0:13:51.800 --> 0:13:54.600 have some firm evidence of that connection. Namely, we know 0:13:54.720 --> 0:13:57.520 that exercise increases the number of certain molecules in the 0:13:57.520 --> 0:14:00.719 brain that are crucial for cognition. Because apple, there's one 0:14:00.720 --> 0:14:05.360 molecule called brain derived neurotrophic factor, or b d NF, 0:14:05.640 --> 0:14:08.360 and that stimulates the growth and survival of brain cells 0:14:08.440 --> 0:14:11.800 and even helps facilitate communication between them. And there have 0:14:11.840 --> 0:14:14.360 been some studies on rats that have shown that physical 0:14:14.400 --> 0:14:17.080 activity boost b d n F levels in the hippocampus, 0:14:17.400 --> 0:14:19.360 which is a part of the brain that's super important 0:14:19.400 --> 0:14:22.360 for learning and even memory function, all right, but how 0:14:22.440 --> 0:14:25.120 exactly does that help the rats? Well, that higher level 0:14:25.160 --> 0:14:27.800 of b d NF actually allowed them to better remember 0:14:27.840 --> 0:14:30.720 how they find their way through underwater mazes, and there 0:14:30.760 --> 0:14:33.280 are tons of studies that suggest that same kind of 0:14:33.320 --> 0:14:36.680 mental improvement from fitness happens in humans as well well. 0:14:36.680 --> 0:14:38.920 A better brain is definitely a nice perk. But there's 0:14:38.920 --> 0:14:41.720 another mental benefit to exercise that I like even more, 0:14:41.800 --> 0:14:44.600 and that's mood enhancement. You probably heard of runners high 0:14:44.640 --> 0:14:47.320 or exercise high, sure, and I've heard of both of those. 0:14:47.720 --> 0:14:50.160 That's the euphoric feeling you get when you're need even 0:14:50.200 --> 0:14:52.960 a strenuous workout, right. And while most people think it's 0:14:53.000 --> 0:14:56.440 caused by endorphins, you know, those dandy neurochemicals that minimize 0:14:56.480 --> 0:15:00.200 pain and stir up feelings of well being, exercise eyes 0:15:00.200 --> 0:15:03.240 are actually do more to neurotransmitters like sarah tonin and 0:15:03.320 --> 0:15:06.760 neuro epinephrin. So our bodies pump more of these throughout 0:15:06.760 --> 0:15:10.080 our nervous systems during workouts, which elevates our mood and 0:15:10.120 --> 0:15:13.400 helps fight back feelings of stress and depression. Okay, so 0:15:13.840 --> 0:15:16.000 maybe our bodies aren't quite the turn coats. That made 0:15:16.040 --> 0:15:19.040 them out to be. But we've definitely been misinformed about 0:15:19.080 --> 0:15:21.200 the role of exercise and weight loss. How do you 0:15:21.200 --> 0:15:24.520 think this misunderstanding got started? And uh, is there really 0:15:24.560 --> 0:15:28.160 no basis for thinking exercises an effective way to lose weight? Well, 0:15:28.160 --> 0:15:30.800 there's are great questions, but before we exhaust ourselves, but 0:15:30.840 --> 0:15:32.560 we check in with our guests for a little quiz. 0:15:32.600 --> 0:15:41.880 Sound so our guest today is partially responsible for our 0:15:41.920 --> 0:15:45.240 interest in today's topic. His research has contributed to a 0:15:45.320 --> 0:15:48.720 much better understanding of the relationship between our daily activity, 0:15:48.720 --> 0:15:52.800 our daily calorie consumption and energy use and calorie burning 0:15:52.840 --> 0:15:54.920 and all of that. And his name just kind of 0:15:54.960 --> 0:15:57.280 sounds like he should have a theory named for him. 0:15:57.400 --> 0:16:00.680 Herman Ponzer welcomed his part time genius. Hi, how you 0:16:00.760 --> 0:16:03.920 doing doing well? Thank you? See what I mean, Manga, 0:16:03.880 --> 0:16:06.600 I mean, can't you just imagine something called the Herman 0:16:06.640 --> 0:16:12.640 Ponser theory of why we're still so freaking fat? Sounds right? Yeah, yeah, 0:16:12.640 --> 0:16:15.160 we'll see if we can make that happen. So all right, Herman, Well, 0:16:15.240 --> 0:16:17.800 let's just start with your research. And Tanzania, I mean, 0:16:17.840 --> 0:16:19.920 which got a lot of attention a few years ago, 0:16:20.000 --> 0:16:22.480 and people are still talking about it. Can you tell 0:16:22.560 --> 0:16:24.840 us why you were studying there and and and just 0:16:24.920 --> 0:16:29.120 let our listeners know about your findings from that research. Sure. Well, 0:16:29.120 --> 0:16:32.080 I'm an evolutionary biologist who's interested in how humans got 0:16:32.120 --> 0:16:33.440 to be the way they are and how the human 0:16:33.480 --> 0:16:37.040 body works from a kind of an evolutionary perspective. Um. 0:16:37.080 --> 0:16:41.040 And of course humans we've all spent the most most 0:16:41.080 --> 0:16:44.080 of our history as hunter gathers. If you go back, 0:16:44.120 --> 0:16:46.120 you know, a couple of thousand years, all of us 0:16:46.120 --> 0:16:49.080 are hunting and gathering, and you know, back two million 0:16:49.120 --> 0:16:50.960 years ago and didnting gathering kind of starts. So we 0:16:51.000 --> 0:16:54.440 have a long evolutionary history of hunting the gathering. Uh. 0:16:54.480 --> 0:16:58.240 Not many populations hunt and gather anymore, um, but that 0:16:58.280 --> 0:17:02.280 makes sort of understanding how their lifestyles and their you know, 0:17:02.320 --> 0:17:04.880 their physiology works all the more important because we think 0:17:04.880 --> 0:17:08.240 it's a really important sort of uh touchstone for understanding 0:17:08.240 --> 0:17:11.040 how our bodies work, even in our weird environments today. 0:17:11.520 --> 0:17:14.439 So in northern Tanzania, there's a population called the Hadza, 0:17:14.520 --> 0:17:17.600 who are one of the last UH populations on Earth 0:17:17.680 --> 0:17:21.080 that are still hunt and gather regularly, so they don't 0:17:21.119 --> 0:17:24.959 have any crops or domesticated animals or vehicles or guns 0:17:25.000 --> 0:17:27.560 or machines or anything like that. They wake up every 0:17:27.600 --> 0:17:31.040 morning and go off and hunt wild game and gather 0:17:31.359 --> 0:17:34.160 wild plant foods, just like you know all of us, 0:17:34.200 --> 0:17:38.439 did you know, just a few generations ago. Uh. And 0:17:38.520 --> 0:17:42.480 so there's this really amazing and cool and generous and 0:17:42.480 --> 0:17:45.320 wonderful population to work with to try to understand how 0:17:45.359 --> 0:17:48.560 that lifestyle affects the way our bodies work. And one 0:17:48.560 --> 0:17:50.560 of the fundamental things we wanted to understand was how 0:17:50.600 --> 0:17:52.960 many calories they burn every day, because we thought, well, 0:17:53.000 --> 0:17:55.960 they're so active. We know they're extremely active, but they've 0:17:55.960 --> 0:17:58.960 burned tons more calories every day than we do here 0:17:59.000 --> 0:18:00.800 in you know, in the US, US and Europe another 0:18:00.960 --> 0:18:05.639 kind of westernized societies. And what we found instead, to 0:18:05.720 --> 0:18:08.440 our huge surprise, was they burned the same number of 0:18:08.440 --> 0:18:11.560 calories every day as you and I do. Wow. So 0:18:11.680 --> 0:18:14.960 if they were wearing a fitbit or something like that, 0:18:15.040 --> 0:18:16.840 would it, I mean, it would tell them that they 0:18:16.840 --> 0:18:20.360 had burned probably thousands more calories than they actually had. 0:18:20.480 --> 0:18:22.520 Is that true? Or you're right, yeah, the fit that 0:18:22.560 --> 0:18:25.160 would tell them the same lies that it tells you, 0:18:25.480 --> 0:18:28.840 which you know, however, active you are, determines how many 0:18:28.840 --> 0:18:31.320 calories you burned. So we know from other studies that 0:18:31.320 --> 0:18:35.720 we've done since that they just to confirm our intuitions there. Uh, 0:18:35.760 --> 0:18:37.680 and this is obvious to anybody who's works with these 0:18:37.760 --> 0:18:41.520 With these folks, Uh, they are incredibly physically active, sort 0:18:41.520 --> 0:18:43.880 of like three to five times more physically active every 0:18:43.960 --> 0:18:48.280 day than the average westerner. Um. And yet despite that, 0:18:48.920 --> 0:18:51.040 they're still burning the same number of calories as we do. 0:18:51.320 --> 0:18:53.400 So you know, they're also really healthy. They have really 0:18:53.440 --> 0:18:56.040 healthy hearts and immune systems. They don't have diabetes or 0:18:56.000 --> 0:18:58.119 anything like that. We think the physical activity is a 0:18:58.160 --> 0:19:00.800 big part of that. So it's important for health, but 0:19:00.920 --> 0:19:04.720 it's not what keeping them, you know, sort of protected 0:19:04.720 --> 0:19:07.320 from obesity. Yeah, and that's a big part of what 0:19:07.320 --> 0:19:09.439 we're trying to remind our listeners of today is just 0:19:09.520 --> 0:19:12.439 because there's not this as strong of a connection as 0:19:12.480 --> 0:19:16.080 we might have thought between exercise and weight loss, they're 0:19:16.200 --> 0:19:20.400 obviously very real benefits to doing the exercise that we do. Yeah, 0:19:20.440 --> 0:19:22.040 that's a really important point because you know, when we 0:19:22.080 --> 0:19:23.719 came out with this study and said, hey, look, these 0:19:23.800 --> 0:19:27.760 hunter gather folks who are important to understand our history 0:19:27.800 --> 0:19:31.320 and and how our bodies work. Um, and we thought 0:19:31.320 --> 0:19:32.879 that they would burn so many work colgies and and 0:19:32.960 --> 0:19:36.320 the rest of us do. Turns out that that's not true. Um. 0:19:36.440 --> 0:19:39.880 The response that we got was, you know, emails from 0:19:39.920 --> 0:19:41.720 out of the blue saying, you know, you're destroying the 0:19:41.760 --> 0:19:45.160 world because you're telling people not to exercise, right, And 0:19:45.200 --> 0:19:46.680 of course that's not what we were saying at all. 0:19:46.840 --> 0:19:48.840 You still to exercise is still important for your health. 0:19:48.920 --> 0:19:50.359 It's just that it doesn't work the way that we 0:19:50.600 --> 0:19:52.920 thought it work, which was the exciting and fun part 0:19:52.920 --> 0:19:55.320 of the science. You know, something that's been puzzling to us. 0:19:55.359 --> 0:19:57.919 And this really isn't related exactly to the HODSA, but 0:19:58.640 --> 0:20:01.040 you know, you remember during previous summer Olympics when you'd 0:20:01.080 --> 0:20:03.560 see all these stories on Michael Phelps and his daily 0:20:03.600 --> 0:20:07.720 diet and Michaels questions. I knew it was exactly So yeah, 0:20:07.800 --> 0:20:10.240 you had to know it was coming. So so just 0:20:10.400 --> 0:20:14.880 I mean, and again of that's that this is called 0:20:14.880 --> 0:20:18.600 the Ponser effect. So, um, so the the insane amount 0:20:18.640 --> 0:20:21.400 of food that he would eat in order to keep 0:20:21.480 --> 0:20:24.679 up with his fitness regiment. I mean, how was he 0:20:24.760 --> 0:20:28.360 not super fat during this process? Yeah? Well, so there's 0:20:28.400 --> 0:20:31.240 two cans. There's at least two pieces of this. One 0:20:31.320 --> 0:20:34.920 is that, um, Michael Phelps is not a normal human 0:20:35.600 --> 0:20:38.720 and uh that's obvious if you watch him swim and 0:20:38.760 --> 0:20:42.720 how fast he is an amazing as he is an athlete. UM. 0:20:42.800 --> 0:20:46.360 And so you know what he's doing during those those 0:20:46.800 --> 0:20:49.760 workout you know cycles where he's burning ten talent colories. 0:20:50.320 --> 0:20:53.200