WEBVTT - Is Exercising to Lose Weight a Myth? 0:00:00.160 --> 0:00:02.680 Guess what, Mango, what's that? Will do? You remember back 0:00:02.680 --> 0:00:04.720 in two thousand and eight when Michael Phelps had that 0:00:04.840 --> 0:00:07.200 daily diet that got so much attention because he was 0:00:07.240 --> 0:00:09.960 eating these insane amounts of food. Yeah, he was eating 0:00:10.000 --> 0:00:12.800 something like eight thousand calories a day. You try twelve 0:00:12.840 --> 0:00:15.280 thousand cowers a day during his peak training, he need 0:00:15.320 --> 0:00:19.160 a whole pizza, pound of pasta, three fried eggs, French toast, 0:00:19.239 --> 0:00:22.160 multiple burgers, and it seemed like anything else he could 0:00:22.160 --> 0:00:25.080 get his hands on, which seems so gross but also 0:00:25.280 --> 0:00:29.000 kind of the best thing ever. And during those same Olympics, 0:00:29.040 --> 0:00:32.920 Hussein Bolt reportedly ate forty seven thousand calories worth of 0:00:33.000 --> 0:00:37.600 chicken McNuggets. Yeah, he was eating them with fries for breakfast, lunch, 0:00:37.840 --> 0:00:41.800 and dinner. That seems at less great. Yeah, but wouldn't 0:00:41.840 --> 0:00:44.640 sixteen year old Mango think of it's pretty incredible. So 0:00:44.680 --> 0:00:46.879 I started thinking about this, and I know you've been 0:00:46.920 --> 0:00:48.839 getting back into the tennis, and I've been running a 0:00:48.840 --> 0:00:51.559 good bet these past few years. But I thought, if 0:00:51.560 --> 0:00:53.720 I could just take this to the extreme, I may 0:00:53.720 --> 0:00:56.560 be able to follow a similar diet. Like let's say 0:00:56.600 --> 0:00:58.840 I'm running twenty miles a week, right, now, and I 0:00:58.920 --> 0:01:02.080 just keep doubling up for the next five weeks, I'd 0:01:02.080 --> 0:01:04.759 be running six hundred and forty miles a week by 0:01:04.800 --> 0:01:07.040 the end of this. I'm so excited about this. Then 0:01:07.080 --> 0:01:09.959 I could eat like twelve Chipotle burritos every day and 0:01:10.040 --> 0:01:12.600 still have room for a half dozen Wendy Spicy Chicken 0:01:12.680 --> 0:01:15.440 sandwiches and maybe even a couple of those naked chicken 0:01:15.520 --> 0:01:18.120 choloopas after I run for the border. It's gonna be great. 0:01:18.800 --> 0:01:21.880 But after our research for today's episodes, Science may have 0:01:21.959 --> 0:01:25.360 crushed my dreams again. It turns out there's not quite 0:01:25.360 --> 0:01:28.080 as strong of a connection between exercise and weight loss 0:01:28.120 --> 0:01:30.560 as we once thought. So that's what we're gonna talk 0:01:30.600 --> 0:01:55.680 about today. Stupid science. Yeah day their podcast listeners, Welcome 0:01:55.720 --> 0:01:58.080 to Part Time Genius. I'm Will Pearson and as always 0:01:58.080 --> 0:02:00.560 I'm joined by my good friend Man guesh Ticket and 0:02:00.600 --> 0:02:04.200 today we're diving into the topic of exercise, its benefits, 0:02:04.240 --> 0:02:07.120 it's limitations, whether it can actually help us shed some 0:02:07.280 --> 0:02:10.359 unwanted pounds, and if it really makes us healthier people. 0:02:10.840 --> 0:02:13.200 And fear not. We also have a couple of our patented, 0:02:13.280 --> 0:02:15.440 ridiculous quizzes along the way. Who've we got on the 0:02:15.440 --> 0:02:18.119 line today A mango. So we'll be talking to Herman Pontzer, 0:02:18.160 --> 0:02:20.960 and anthropology professor at Hunter College in New York City. 0:02:21.320 --> 0:02:25.120 He's responsible for some truly incredible research on exercise, and 0:02:25.160 --> 0:02:26.880 he's gonna help us get to the bottom of just 0:02:26.919 --> 0:02:30.360 how useful physical activity really is for burning calories. We're 0:02:30.400 --> 0:02:32.720 also going to talk to a couple of personal trainers 0:02:32.760 --> 0:02:34.400 and see if we can whip them into shape through 0:02:34.440 --> 0:02:38.160 the power of our trivia. Right, So, before today's episode, 0:02:38.520 --> 0:02:40.800 I would have told you that exercising is probably the 0:02:40.840 --> 0:02:43.360 best way to lose weight, simply based on the conventional 0:02:43.400 --> 0:02:47.720 wisdom of calories in, calories out. I mean that sounds sensible, right, Sure, 0:02:47.800 --> 0:02:50.200 We're taken calories through what we eat and drink and 0:02:50.200 --> 0:02:53.080 then burn them up through exercise. The more you exercise, 0:02:53.160 --> 0:02:55.760 the more calories you burn, and the more weight you lose. 0:02:55.919 --> 0:02:58.560 It just makes sense, it does. But there are actually 0:02:58.560 --> 0:03:00.720 all these studies conducted over the last few years that 0:03:00.800 --> 0:03:04.360 suggests exercise really isn't an effective way to lose excess weight. 0:03:04.800 --> 0:03:08.000 For example, Dr Timothy Church at the Pennington Biomedical Research 0:03:08.040 --> 0:03:10.720 Center at l s U. He held an experiment where 0:03:10.800 --> 0:03:14.240 hundreds of overweight women were given strict workout regiments for 0:03:14.280 --> 0:03:17.320 six months. The one group of them exercised a little 0:03:17.320 --> 0:03:19.760 over an hour each week, another one for a little 0:03:19.760 --> 0:03:23.400 over two hours, and another for over three hours. There 0:03:23.480 --> 0:03:25.560 was also a fourth group that stuck to their typical 0:03:25.680 --> 0:03:29.320 routine and didn't exercise at all. And against all logic 0:03:29.400 --> 0:03:31.799 and fairness, there was no major difference in the weight 0:03:31.840 --> 0:03:34.280 loss between the women who had exercised and the ones 0:03:34.320 --> 0:03:35.960 who had And how pissed would you be if you 0:03:36.040 --> 0:03:38.720 were that three hour group. In fact, some of the 0:03:38.760 --> 0:03:42.240 women in the exercise groups actually gained weight, which doesn't 0:03:42.240 --> 0:03:44.960 seem fair at all. I mean, they put in the work, 0:03:45.000 --> 0:03:47.480 they deserve a reward. Well, it's funny you should say that, 0:03:47.520 --> 0:03:51.360 because Church actually concluded that the rewards were the problem. 0:03:51.360 --> 0:03:54.360 You know, exercise stimulates appetite, and many of the women 0:03:54.400 --> 0:03:58.200 counteracted their work by over eating afterward. Church suggested that 0:03:58.240 --> 0:04:00.160 it was justified in their minds. Is kind of a 0:04:00.240 --> 0:04:03.720 self reward for all the energy that exerted through exercise. Yeah, 0:04:03.760 --> 0:04:05.480 we hear that sort of thinking all the time, like 0:04:05.640 --> 0:04:08.480 cheat days and junk food rewards for going to the gym. 0:04:08.560 --> 0:04:11.880 But if we're canceling out the calories we burn. Then 0:04:11.880 --> 0:04:15.160 we're probably imagining our workouts to be much more effective 0:04:15.160 --> 0:04:17.680 than they really are. I mean, the Department of Health 0:04:17.680 --> 0:04:20.599 and Human Services recommends people aim for at least thirty 0:04:20.600 --> 0:04:23.640 minutes of physical activity every day, But at thirty minute 0:04:23.680 --> 0:04:26.960 workout that only burns about two hundred calories, and the 0:04:27.040 --> 0:04:30.440 average slice of pizza contains close to like three hundred calories. 0:04:30.720 --> 0:04:32.800 So you can see how the math doesn't quite work. 0:04:32.960 --> 0:04:36.400 It's really just not fair at all. But it isn't 0:04:36.400 --> 0:04:40.200 just those powerful post workout indulgences that counteract calories burned 0:04:40.240 --> 0:04:43.360 through exercise. You know, the things we consume in preparation 0:04:43.480 --> 0:04:46.480 for or even during a workout can also take a toll, 0:04:46.680 --> 0:04:48.800 which is a good point. I mean, those two hundred 0:04:48.800 --> 0:04:51.280 calories you burned during your thirty minutes on the treadmill, 0:04:51.640 --> 0:04:54.000 every single one goes right back into your body thanks 0:04:54.000 --> 0:04:56.560 to that bottle of gatorade or that energy bar you 0:04:56.640 --> 0:04:59.159 might have scarfed down while running right right, And the 0:04:59.200 --> 0:05:01.320 same goes for the eagle or the oatmeal used to 0:05:01.360 --> 0:05:04.440 carbo load before your workout. And we think the energy 0:05:04.480 --> 0:05:06.679 from these meals is going to help us power through 0:05:06.839 --> 0:05:09.520 and burn more calories at the gym, But it's actually 0:05:09.520 --> 0:05:11.880 the calories from those pregame foods that are going to 0:05:11.920 --> 0:05:14.440 get burned off first. And why is that Well, because 0:05:14.440 --> 0:05:17.240 sugar from what you've just consumed will still be floating 0:05:17.279 --> 0:05:20.719 freely in your bloodstream, and it takes muscle tissue much 0:05:20.800 --> 0:05:23.039 less energy to take that sugar than it does to 0:05:23.080 --> 0:05:26.320 burn off the existing fat stores. So your most recent 0:05:26.400 --> 0:05:29.080 meal will always be the first to go during a workout. 0:05:29.279 --> 0:05:31.760 But we can always just exercise a little longer, right, 0:05:31.800 --> 0:05:35.200 I mean, once those preliminary calories are gone, our muscle 0:05:35.240 --> 0:05:38.080 cells will start tipping away at storage fat for fuel. Well, 0:05:38.120 --> 0:05:41.000 I mean yes and no. According to some breakthrough research 0:05:41.040 --> 0:05:43.280 from Herman pons Er, there are a lot of assumptions 0:05:43.279 --> 0:05:46.880 we've been making about human metabolism that they're not quite right. 0:05:47.000 --> 0:05:49.600 So you know, it's true that a longer workout would 0:05:49.680 --> 0:05:53.200 result in more calories burned and even some from storage fat. 0:05:53.839 --> 0:05:55.880 But we know there's a limit to how many calories 0:05:55.920 --> 0:05:58.719 your body will metabolize in any given day. So I'm 0:05:58.800 --> 0:06:01.359 definitely intrigued. But before we get too far into this, 0:06:01.480 --> 0:06:05.280 we should probably clarify the basics of metabolism. All right, 0:06:05.279 --> 0:06:08.839 well I'll let you do that. Go for it, okay. 0:06:09.040 --> 0:06:13.200 So metabolism is basically the sum of all the processes 0:06:13.240 --> 0:06:17.200 that takes place in our bodies. We're talking digestion, respiration, 0:06:17.480 --> 0:06:20.760 the production of cells, the movement of substances between cells, 0:06:20.880 --> 0:06:24.560 you name it, and all these processes require energy, which 0:06:24.600 --> 0:06:27.960 our bodies released from the calories we consume. So even 0:06:28.040 --> 0:06:31.520 without exercise and other forms of physical activity, we still 0:06:31.680 --> 0:06:35.560 burned through or metabolize a huge number of calories simply 0:06:35.600 --> 0:06:38.880 by being alive. Yeah, exactly. So back to Herman Ponsers 0:06:38.920 --> 0:06:43.280 World Shattering Research and February's issue of Scientific American, Herman 0:06:43.400 --> 0:06:46.000 shared findings from his study of the Hadza tribe and 0:06:46.080 --> 0:06:49.560 rule Tanzania. He and other researchers spent a whole month 0:06:49.640 --> 0:06:51.960 living with the Hatsa, who were one of the last 0:06:52.000 --> 0:06:55.560 traditional hunter gatherer cultures left on Earth. It was during 0:06:55.600 --> 0:06:58.279 this time that Herman and his partners recorded measurements of 0:06:58.320 --> 0:07:01.880 the daily energy expenditures of a couple dozen tribesmen and women. 0:07:02.600 --> 0:07:05.000 So this allowed them to compare the daily calorie burn 0:07:05.040 --> 0:07:07.880 of a society in which every member is highly active 0:07:07.960 --> 0:07:10.400 to a Western society like our own and which members 0:07:10.400 --> 0:07:14.360 are more you know, sedentary. Well, back up a second. 0:07:14.600 --> 0:07:18.280 You said the researchers measured the hadzas daily energy expenditure. 0:07:18.560 --> 0:07:21.080 But I'm wondering how they pull that off. Are you 0:07:21.120 --> 0:07:23.440 really wondering that mango orre you just sensing there's an 0:07:23.440 --> 0:07:27.800 opportunity here to talk about doubly labeled water? Of course 0:07:27.840 --> 0:07:31.320 it is, you know, I love the d LW. Doubly 0:07:31.440 --> 0:07:34.600 Labeled water is the special water in which the hydrogen 0:07:34.760 --> 0:07:38.760 and oxygen molecules have been either partly or entirely replaced 0:07:38.800 --> 0:07:42.200 with heavy isotopes that aren't usually found in the human body. 0:07:42.520 --> 0:07:46.360 And it's safe to drink this stuff completely. They're stable isotopes, 0:07:46.400 --> 0:07:49.760 so they're non radioactive. But here's what's great about them. 0:07:49.800 --> 0:07:53.360 After somebody drinks d l W that's been enriched, researchers 0:07:53.360 --> 0:07:57.280 suddenly have this tracking mechanism. Basically, by measuring the concentration 0:07:57.320 --> 0:08:01.200 found in urine samples, researchers can determine person's daily rate 0:08:01.200 --> 0:08:04.640 of carbon dioxide production. And since carbon dioxide is a 0:08:04.640 --> 0:08:08.640 waste product of our bodies energy making processes, calculating how 0:08:08.720 --> 0:08:11.120 much c O two someone produces in a day is 0:08:11.160 --> 0:08:14.120 the best way to measure their energy expenditure. That is 0:08:14.160 --> 0:08:17.400 pretty neat. Yeah, Doubly labeled water has become the gold 0:08:17.480 --> 0:08:20.760 standard for measuring how much energy a person consumes. Like, 0:08:20.800 --> 0:08:23.920 the margin of error is pretty small, and in fact, 0:08:24.000 --> 0:08:27.560 the only downside is the cost. D LW is expensive, 0:08:27.960 --> 0:08:30.720 like are we talking smart water expensive or like Fiji 0:08:30.720 --> 0:08:33.840 water expensive? No, it's so much more than that. Dl 0:08:34.000 --> 0:08:38.680 W runs researchers about dollars per test subjects. Actually, you 0:08:38.679 --> 0:08:41.480 know what this really expensive water reminds me of? And 0:08:41.520 --> 0:08:44.199 I know that this is totally off topic, but did 0:08:44.200 --> 0:08:46.240 you know that the federal government actually sells a two 0:08:47.280 --> 0:08:50.920 jar of peanut butter and there's just six ounces of 0:08:50.920 --> 0:08:53.880 peanut butter in there. It's like a tiny jar. And 0:08:54.120 --> 0:08:56.520 it also goes by this incredibly catchy name. Are you 0:08:56.520 --> 0:09:00.520 ready for it? Standard Reference Material number two, three eights 0:09:00.559 --> 0:09:03.480 of it. Oh, that sounds delicious, But why is it 0:09:03.520 --> 0:09:06.320 actually so expensive? Is it more delicious? No, it's the 0:09:06.400 --> 0:09:09.840 wonkiest reason ever. It's the super precise like peanut butter, 0:09:09.960 --> 0:09:14.200 with specific levels of amino acids and fats and carcinogens. 0:09:14.280 --> 0:09:17.319 And it's mostly used for quality controls so companies can 0:09:17.360 --> 0:09:20.400 test their standards against the governments and make sure it 0:09:20.440 --> 0:09:23.679 measures up. But as a result, no one actually eats 0:09:23.679 --> 0:09:26.720 the peanut butter. It's just for lab purposes, which only 0:09:26.760 --> 0:09:28.760 makes me want to try it more like with a 0:09:28.880 --> 0:09:32.920 really cheap jelly. All well, let's get back to D. L. W. 0:09:33.080 --> 0:09:34.880 Let me tell you what herman and his partners were 0:09:34.920 --> 0:09:37.160 actually able to learn from having the Hods of tribe 0:09:37.200 --> 0:09:39.560 drink it lay it on me. Well, first, let me 0:09:39.600 --> 0:09:41.800 preface this by saying that the Hods are the kings 0:09:41.840 --> 0:09:45.440 and queens of exercise. Every single day, the men trek 0:09:45.559 --> 0:09:48.120 miles and miles to hunt for game with homemade bows 0:09:48.160 --> 0:09:51.440 and arrows. They scale forty foot trees to hack tree 0:09:51.480 --> 0:09:54.760 limbs with hatchets and gather wild honey. Now, the women 0:09:54.840 --> 0:09:57.679 forage all day for wild berries and other edible plants 0:09:57.679 --> 0:10:00.360 like tubers that they dig out at the ground with x. 0:10:00.880 --> 0:10:02.960 Even the kids of the tribe are put to work 0:10:02.960 --> 0:10:06.760 by hauling pails of water from a mile or more away. Okay, 0:10:06.760 --> 0:10:09.280 so they're seriously active and no one sitting at their 0:10:09.320 --> 0:10:12.120 desks right, definitely not. But what the researchers found was 0:10:12.160 --> 0:10:15.280 that even though the Hadzas lives are far more physically demanding. 0:10:15.679 --> 0:10:17.960 The amount of calories they ate and burned through in 0:10:17.960 --> 0:10:20.600 the day was the same as in Europe and the US, 0:10:21.080 --> 0:10:23.960 and the men went through about twenty six hundred calories 0:10:24.000 --> 0:10:27.000 a day and the women burned through about nineteen hundred. 0:10:27.240 --> 0:10:30.360 According to Herman, we looked at the data every way imaginable, 0:10:30.400 --> 0:10:33.800 accounting for the effects of body size, fat percentage, age, 0:10:33.880 --> 0:10:37.520 and sex. No difference at all, which is insane, isn't it. 0:10:37.559 --> 0:10:40.480 I mean that you naturally assume that physically active people 0:10:40.520 --> 0:10:43.559 would burn more calories, of course, but the research really 0:10:43.559 --> 0:10:46.000 doesn't bear that out. In fact, they did a follow 0:10:46.080 --> 0:10:48.840 up study with about three hundred participants and it showed 0:10:48.840 --> 0:10:51.679 the exact same thing. The people who were the most 0:10:51.720 --> 0:10:54.400 active burned the same daily amount of calories as those 0:10:54.400 --> 0:10:58.240 who were only moderately, and the participants who barely left 0:10:58.280 --> 0:11:01.600 the couch at all burned about two fewer calories than them, 0:11:01.640 --> 0:11:03.520 the same amount they would have burned from a mere 0:11:03.600 --> 0:11:06.480 thirty minutes of exercise. Doesn't seem to suggest that our 0:11:06.520 --> 0:11:10.400 metabolisms are like fixed like. It almost seems like there's 0:11:10.440 --> 0:11:12.760 a preset amount of calories that your body is willing 0:11:12.800 --> 0:11:15.800 to burn in any given day, and no matter how 0:11:15.840 --> 0:11:18.240 far you run or how many push ups you do, 0:11:18.400 --> 0:11:20.880 you won't be able to top that max limit. But 0:11:21.000 --> 0:11:24.320 my bigger question is this, why doesn't the Hadza hunter 0:11:24.480 --> 0:11:26.960 burn more in day than the average office worker. Well, 0:11:27.000 --> 0:11:29.280 I'm not sure we really have the answer to that yet, 0:11:29.320 --> 0:11:32.120 but one thing I've seen researches suggest is that our 0:11:32.160 --> 0:11:35.280 bodies account for the calories burned through physical activity by 0:11:35.360 --> 0:11:38.000 dialing back on the number of calories we devote to 0:11:38.040 --> 0:11:42.720 the background functions that keep us alive. About six of 0:11:42.760 --> 0:11:46.080 the calories we burn each day go to these unseen 0:11:46.240 --> 0:11:49.880 or unconscious processes, so it's possible that when our physical 0:11:49.920 --> 0:11:55.280 activity pushes us beyond that other daily cloric expenditure, our 0:11:55.320 --> 0:11:57.440 body is just cut back on the calories spin on 0:11:57.480 --> 0:12:00.800 metabolic processes. This would help even the scales and keep 0:12:00.840 --> 0:12:03.400 us from exceeding our preset energy budget for the day, 0:12:03.520 --> 0:12:07.600 which is really cool but also disheartening. Right, no wonder, 0:12:07.640 --> 0:12:11.360 I've got this paunch. I feel so betrayed unt I'll 0:12:11.400 --> 0:12:14.599 take it too hard. So a fixed daily energy expenditure 0:12:14.600 --> 0:12:17.360 limit is likely, and evolved trade meant to help conserve 0:12:17.440 --> 0:12:20.640 our fat stores for when we really need them. I mean, 0:12:20.679 --> 0:12:23.000 imagine if the Hotsa hunters were free to burn through 0:12:23.040 --> 0:12:25.760 ten thousand calories during a hunt instead of the typical 0:12:25.800 --> 0:12:28.120 two thousand or so, if they were to come up 0:12:28.120 --> 0:12:30.760 empty handed, they would have lost five days worth of 0:12:30.800 --> 0:12:34.800 calories in one with no prospects for replacing them. And 0:12:34.840 --> 0:12:37.160 at that rate they're already limited. Fat stores will be 0:12:37.200 --> 0:12:39.440 depleted in no time, and they'd find themselves on the 0:12:39.440 --> 0:12:42.319 brink of starvation. Which is a great point but still 0:12:42.480 --> 0:12:44.800 doesn't make you feel like maybe all that time spent 0:12:44.880 --> 0:12:47.719 exercising was I don't know, kind of a waste. Well, no, 0:12:47.840 --> 0:12:50.640 hold on a second, so don't forget that exercise has 0:12:50.679 --> 0:12:53.680 all kinds of great benefits beyond weight loss. For starters, 0:12:53.720 --> 0:12:57.280 exercises fantastic for your heart and blood vessels. It makes 0:12:57.280 --> 0:13:01.160 your heart contract with greater force and frequency, which increases 0:13:01.160 --> 0:13:04.520 blood flow leads to less artery clogging. There's also plenty 0:13:04.559 --> 0:13:07.520 of evidence that exercise helps reduce the risk of some cancers, 0:13:07.559 --> 0:13:11.240 as well as type two diabetes and cardiovascular disease. But 0:13:11.280 --> 0:13:14.360 one of my favorite benefits of exercise that often goes overlooked. 0:13:14.720 --> 0:13:17.080 Not only does it help strengthen your muscles, it helps 0:13:17.080 --> 0:13:20.720 strengthen your bones too. Just like muscles, bones grow stronger 0:13:20.760 --> 0:13:23.040 when they've been made to carry more weight than normal. 0:13:23.400 --> 0:13:26.439 So your muscles contract during exercise, they apply force to 0:13:26.520 --> 0:13:29.400 the bones that support those parts of the body. The 0:13:29.480 --> 0:13:32.280 added force stimulates the bones and causes them to reinforce 0:13:32.320 --> 0:13:35.080 themselves by building new tissue, which is really cool. But 0:13:35.200 --> 0:13:37.600 you know, Will, I'm pretty sure we'd have to forfeit 0:13:37.640 --> 0:13:40.000 our part time Genius membership cards if we miss the 0:13:40.040 --> 0:13:42.360 chance to talk about some of the more amazing mental 0:13:42.400 --> 0:13:46.640 benefits of exercise, like thanks to Fernando Gomez Pinia, a 0:13:46.760 --> 0:13:49.400 neuro surgery professor at U c l A, we now 0:13:49.440 --> 0:13:52.200 have some firm evidence of that connection. Namely, we know 0:13:52.320 --> 0:13:55.120 that exercise increases the number of certain molecules in the 0:13:55.160 --> 0:13:58.280 brain that are crucial for cognition. For example, there's one 0:13:58.320 --> 0:14:02.240 molecule called brain derived I have neurotrophic factor, or b 0:14:02.360 --> 0:14:05.200 d NF, and that stimulates the growth and survival of 0:14:05.200 --> 0:14:09.160 brain cells and even helps facilitate communication between them. And 0:14:09.200 --> 0:14:11.360 there have been some studies on rats that have shown 0:14:11.400 --> 0:14:14.680 that physical activity boost b d NF levels in the hippocampus, 0:14:15.000 --> 0:14:16.960 which is a part of the brain that's super important 0:14:17.000 --> 0:14:19.960 for learning and even memory function, all right, but how 0:14:20.040 --> 0:14:22.720 exactly does that help the rats? Well, that higher level 0:14:22.760 --> 0:14:25.400 of b d NF actually allowed them to better remember 0:14:25.440 --> 0:14:28.320 how they find their way through underwater mazes, and there 0:14:28.360 --> 0:14:30.920 are tons of studies that suggest that same kind of 0:14:30.920 --> 0:14:34.280 mental improvement from fitness happens in humans as well well. 0:14:34.280 --> 0:14:36.520 A better brain is definitely a nice perk. But there's 0:14:36.560 --> 0:14:39.320 another mental benefit to exercise that I like even more, 0:14:39.400 --> 0:14:42.200 and that's mood enhancement. You probably heard of runners high 0:14:42.240 --> 0:14:44.920 or exercise high, sure, and I've heard of both of those. 0:14:45.320 --> 0:14:47.760 That's the euphoric feeling you get when you're need even 0:14:47.800 --> 0:14:50.560 a strenuous workout, right. And while most people think it's 0:14:50.600 --> 0:14:54.040 caused by endorphins, you know, those dandy neurochemicals that minimize 0:14:54.080 --> 0:14:57.800 pain and stir up feelings of well being, exercise highs 0:14:57.800 --> 0:15:01.880 are actually do more to neurotransmitters serotonin and neuro epinephrin, 0:15:02.360 --> 0:15:04.800 So our bodies pump more of these throughout our nervous 0:15:04.800 --> 0:15:08.240 systems during workouts, which elevates our mood and helps fight 0:15:08.240 --> 0:15:11.840 back feelings of stress and depression. Okay, so maybe our 0:15:11.840 --> 0:15:13.960 bodies aren't quite the turn coats I made them out 0:15:13.960 --> 0:15:17.000 to be. But we've definitely been misinformed about the role 0:15:17.040 --> 0:15:19.080 of exercise and weight loss. How do you think this 0:15:19.200 --> 0:15:22.720 misunderstanding got started? And uh, is there really no basis 0:15:22.800 --> 0:15:25.760 for thinking exercises an effective way to lose weight? Well, 0:15:25.760 --> 0:15:28.400 there's a great questions. But before we exhaust ourselves, but 0:15:28.440 --> 0:15:30.440 we check in with our guests for a little QUIZD. 0:15:37.440 --> 0:15:39.920 So our guest today is partially responsible for our interest 0:15:39.960 --> 0:15:43.120 in today's topic. His research has contributed to a much 0:15:43.120 --> 0:15:46.440 better understanding of the relationship between our daily activity, our 0:15:46.520 --> 0:15:50.480 daily calorie consumption and energy use and calorie burning and 0:15:50.840 --> 0:15:52.880 all of that. And his name just kind of sounds 0:15:52.920 --> 0:15:55.320 like he should have a theory named for him. Herman 0:15:55.360 --> 0:15:58.560 Ponzer welcomed his part time genius. Hi, how you doing. 0:15:59.280 --> 0:16:01.520 I'm doing well? Thank you? See what I mean, Mango, 0:16:01.520 --> 0:16:04.200 I mean, can't you just imagine something called the Herman 0:16:04.280 --> 0:16:10.240 Ponser theory of why we're still so freaking fast? Sounds right? Yeah, yeah, 0:16:10.280 --> 0:16:12.760 we'll see if we can make that happen. So all right, Herman, Well, 0:16:12.840 --> 0:16:15.400 let's just start with your research and Tanzania, I mean, 0:16:15.440 --> 0:16:17.520 which got a lot of attention a few years ago, 0:16:17.600 --> 0:16:20.080 and people are still talking about it. Can you tell 0:16:20.160 --> 0:16:22.440 us why you were studying there and and and just 0:16:22.520 --> 0:16:26.720 let our listeners know about your findings from that research. Sure. Well, 0:16:26.720 --> 0:16:29.680 I'm an evolutionary biologist who's interested in how humans got 0:16:29.720 --> 0:16:31.040 to be the way they are and how the human 0:16:31.080 --> 0:16:34.640 body works from a kind of an evolutionary perspective. Um. 0:16:34.720 --> 0:16:38.640 And of course humans we've all spent the most most 0:16:38.680 --> 0:16:41.640 of our history as hunter gathers. If you go back, 0:16:41.720 --> 0:16:43.720 you know, a couple of thousand years, all of us 0:16:43.760 --> 0:16:46.680 are hunting and gathering, and you know, back two million 0:16:46.720 --> 0:16:48.560 years ago with hunting gathering kind of starts. So we 0:16:48.600 --> 0:16:52.040 have a long evolutionary history of hunting and gathering. Uh. 0:16:52.080 --> 0:16:55.840 Not many populations hunt and gather anymore, um, but that 0:16:55.880 --> 0:16:59.840 makes sort of understanding how they're lifestyles and they're you know, 0:17:00.000 --> 0:17:02.480 their physiology works all the more important because we think 0:17:02.480 --> 0:17:05.800 it's a really important sort of uh touchstone for understanding 0:17:05.840 --> 0:17:08.640 how our bodies work, even in our weird environments today. 0:17:09.119 --> 0:17:12.040 So in northern Candonia, there's a population called the Hotza, 0:17:12.119 --> 0:17:15.200 who are one of the last um populations on Earth 0:17:15.280 --> 0:17:18.800 that still hunt and gather regularly, so they don't have 0:17:18.840 --> 0:17:22.679 any crops or domesticated animals or vehicles or guns or 0:17:22.720 --> 0:17:25.560 machines or anything like that. They wake up every morning 0:17:25.800 --> 0:17:29.280 and go off and hunt wild game and gather wild 0:17:29.280 --> 0:17:32.000 plant foods, just like you know all of us, did 0:17:32.240 --> 0:17:36.439 you know, just a few generations ago. Uh. And so 0:17:36.640 --> 0:17:40.480 there's this really amazing and cool and generous and wonderful 0:17:40.520 --> 0:17:43.040 population to work with to try to understand how that 0:17:43.119 --> 0:17:46.240 lifestyle affects the way our bodies work. And one of 0:17:46.280 --> 0:17:48.400 the fundamental things we wanted to understand was how many 0:17:48.400 --> 0:17:50.800 calories they burned every day, because we thought, well, they're 0:17:50.840 --> 0:17:53.840 so active. We know they're extremely active, but they've burned 0:17:53.840 --> 0:17:56.639 tons more calories every day than we do here in 0:17:56.960 --> 0:17:58.840 you know, in the US and Europe another kind of 0:17:58.880 --> 0:18:04.480 westernized societies. And what we found instead, to our huge surprise, 0:18:05.040 --> 0:18:06.800 was they burned the same number of calories every day 0:18:06.920 --> 0:18:09.920 as you and I do. Wow. So if they were 0:18:09.960 --> 0:18:13.360 wearing a fitbit or something like that, would it, I mean, 0:18:13.440 --> 0:18:16.440 it would tell them that they had burned probably thousands 0:18:16.480 --> 0:18:18.800 more calories than they actually had. Is that true or 0:18:19.040 --> 0:18:21.159 they're right? Yeah, the fit that would tell them the 0:18:21.240 --> 0:18:25.040 same lies that it tells you, which you know, however 0:18:25.080 --> 0:18:27.520 active you are determines how many calories you burned. So 0:18:27.560 --> 0:18:29.680 we know from other studies that we've done since that 0:18:29.840 --> 0:18:33.760 they just to confirm our intuitions there. Uh, and this 0:18:33.800 --> 0:18:36.840 is obvious to anybody who's worked with these With these folks, Uh, 0:18:37.000 --> 0:18:39.639 they are incredibly physically active, sort of like three to 0:18:39.760 --> 0:18:44.600 five times more physically active every day than the average westerner. Um. 0:18:44.680 --> 0:18:47.479 And yet despite that, they're still burning in the same 0:18:47.520 --> 0:18:49.640 number of calories as we do. So you know, they're 0:18:49.680 --> 0:18:52.680 also really healthy. They have really healthy hearts and immune systems, 0:18:52.720 --> 0:18:54.760 they don't have diabetes or anything like that. We think 0:18:54.800 --> 0:18:56.960 the physical activity is a big part of that. So 0:18:57.000 --> 0:19:00.000 it's important for their health, but it's not what keeps 0:19:00.000 --> 0:19:04.040 and um, you know, sort of protected from obesity. Yeah, 0:19:04.040 --> 0:19:05.399 and that's a big part of what we're trying to 0:19:05.400 --> 0:19:08.000 remind our listeners of today is just because there's not 0:19:08.119 --> 0:19:10.480 this as strong of a connection as we might have 0:19:10.520 --> 0:19:15.040 thought between exercise and weight loss, they're obviously very real 0:19:15.080 --> 0:19:18.199 benefits to doing the exercise that we do. Yeah, that's 0:19:18.200 --> 0:19:19.800 a really important point because you know, when we came 0:19:19.840 --> 0:19:21.600 out with this study and said, hey, look, these hunter 0:19:21.720 --> 0:19:26.080 gather folks who are important to understand our history and 0:19:26.080 --> 0:19:29.000 and how our bodies work. Um, and we thought that 0:19:29.000 --> 0:19:30.639 they would burn so many work couties and then the 0:19:30.640 --> 0:19:33.919 rest of us do. Turns out that that's not true. Um. 0:19:34.040 --> 0:19:37.480 The response that we got was, you know, emails from 0:19:37.520 --> 0:19:39.320 out of the blue saying, you know, you're destroying the 0:19:39.359 --> 0:19:42.760 world because you're telling people not to exercise, right, And 0:19:42.800 --> 0:19:44.280 of course that's not what we were saying at all. 0:19:44.440 --> 0:19:46.440 You still to exercise, It's still important for your health. 0:19:46.560 --> 0:19:48.000 It's just that it doesn't work the way that we 0:19:48.200 --> 0:19:50.520 thought it worked, which was the exciting and fun part 0:19:50.520 --> 0:19:52.919 of the science. You know, something that's been puzzling to us. 0:19:52.960 --> 0:19:55.520 And this really isn't related exactly to the HODSA, but 0:19:56.240 --> 0:19:58.560 you know, you remember during previous summer Olympics when you 0:19:58.640 --> 0:20:01.159 see all these stories on Mike Phelps and his daily 0:20:01.200 --> 0:20:04.560 diet and Michael Phelps questions, I knew it was exactly 0:20:04.840 --> 0:20:07.360 so yeah, you had to know it was coming. So 0:20:07.359 --> 0:20:12.480 so just I mean, and again that's this is called 0:20:12.480 --> 0:20:16.200 the Ponser effect. So, um so, the the insane amount 0:20:16.240 --> 0:20:19.000 of food that he would eat in order to keep 0:20:19.119 --> 0:20:22.280 up with his fitness regiment. I mean, how was he 0:20:22.359 --> 0:20:25.680 not super fat during this process. Yeah, well so there's 0:20:26.000 --> 0:20:28.439 two I guess there's at least two pieces of this. 0:20:28.640 --> 0:20:32.160 One is that, um, Michael Felts is not a normal 0:20:32.240 --> 0:20:36.240 human and uh that's obvious if you watch him swim 0:20:36.240 --> 0:20:38.199 and how fast he is an amazing as he is 0:20:38.240 --> 0:20:42.439 an athlete. Um. And so you know what he's doing 0:20:42.520 --> 0:20:46.520 during those those workout you know cycles where he's burning 0:20:46.520 --> 0:20:49.879