1 00:00:08,960 --> 00:00:13,000 Speaker 1: Hey, everybody, welcome to another edition of Wisdom Wednesdays. Today 2 00:00:13,080 --> 00:00:15,600 Speaker 1: we are going to dive into something that is not 3 00:00:15,760 --> 00:00:20,079 Speaker 1: just fascinating, but it's also pretty personal for me because 4 00:00:20,079 --> 00:00:22,919 Speaker 1: we're going to talk about the heart, Your heart, my heart, 5 00:00:23,440 --> 00:00:27,680 Speaker 1: and how incredibly malleable are plastic it really is. And 6 00:00:27,760 --> 00:00:31,040 Speaker 1: if you're not a regular listener, and this is personal 7 00:00:31,120 --> 00:00:34,600 Speaker 1: for me because in January this year, I went through 8 00:00:34,680 --> 00:00:39,159 Speaker 1: open heart surgery to correct a dodgy aortic valve that 9 00:00:39,240 --> 00:00:41,879 Speaker 1: I was actually born with. So we're going to talk 10 00:00:41,920 --> 00:00:45,160 Speaker 1: about today through the lens of one of the most 11 00:00:45,240 --> 00:00:49,960 Speaker 1: groundbreaking studies ever in exercise science, and it's called the 12 00:00:50,080 --> 00:00:53,199 Speaker 1: Dallas bed Rest Study. And then there's been a series 13 00:00:53,240 --> 00:00:56,320 Speaker 1: of studies after that about the Dallas bed Rest and 14 00:00:56,440 --> 00:00:59,560 Speaker 1: Retraining Study and it's kind of got a fifty year 15 00:00:59,640 --> 00:01:04,800 Speaker 1: legacy and this researchs really changed medicine. And after my 16 00:01:04,840 --> 00:01:06,800 Speaker 1: own experience with heart surgery, I can tell you that 17 00:01:06,880 --> 00:01:10,720 Speaker 1: this isn't just theory, it's actually life saving knowledge. And 18 00:01:10,800 --> 00:01:15,280 Speaker 1: it starts. The story starts in nineteen sixty six, five 19 00:01:15,360 --> 00:01:19,200 Speaker 1: healthy young men in their early twenties, fit and no 20 00:01:19,360 --> 00:01:23,840 Speaker 1: health issues, volunteered for a radical experiment what they had 21 00:01:23,920 --> 00:01:27,720 Speaker 1: to do was lie flat on their backs for three weeks. 22 00:01:27,760 --> 00:01:31,680 Speaker 1: No walking, no standing, no sleeky lapse to the fridge, 23 00:01:31,880 --> 00:01:36,640 Speaker 1: just bed rest and probably a student's dream get paid 24 00:01:36,880 --> 00:01:40,880 Speaker 1: to lie in bed for three weeks, But what happened 25 00:01:41,400 --> 00:01:43,840 Speaker 1: was a bit of a wake up call. In just 26 00:01:44,040 --> 00:01:49,440 Speaker 1: twenty one days of complete inactivity, there are cardiovascular systems 27 00:01:49,600 --> 00:01:54,880 Speaker 1: aged by what would normally take thirty years of living. 28 00:01:55,480 --> 00:01:59,240 Speaker 1: Their VO two max, which is they measure the gold 29 00:01:59,240 --> 00:02:03,920 Speaker 1: standard measure of your cardio respiratory fitness or horsepower if 30 00:02:03,960 --> 00:02:08,600 Speaker 1: you like it, actually dropped by twenty seven percent in 31 00:02:08,720 --> 00:02:12,200 Speaker 1: three weeks, and their cardiac output, which is how much 32 00:02:12,280 --> 00:02:15,799 Speaker 1: your blood how much blood sorry, your heart pumps per 33 00:02:15,919 --> 00:02:20,720 Speaker 1: minute plummeted by twenty six percent, and the stroke volume, 34 00:02:20,960 --> 00:02:24,760 Speaker 1: the amount of blood that's pushed out per heartbeat, dropped 35 00:02:24,760 --> 00:02:30,519 Speaker 1: a whopping thirty one percent, and its submaxim sub maximal effort. 36 00:02:30,680 --> 00:02:34,160 Speaker 1: Just like light cycling or light jogging, Their heart rate 37 00:02:34,280 --> 00:02:40,120 Speaker 1: and blood pressure skyrocketed. Their hearts were working harder, just 38 00:02:40,360 --> 00:02:45,360 Speaker 1: doing less, And this was the original use it or 39 00:02:45,560 --> 00:02:49,040 Speaker 1: Lose it research study, But then came a bit of 40 00:02:49,080 --> 00:02:53,240 Speaker 1: a twist. These men spent the next eight weeks in 41 00:02:53,280 --> 00:02:57,520 Speaker 1: a structured endurance training program. And this wasn't a walk 42 00:02:57,560 --> 00:03:01,880 Speaker 1: through the park. It was rigorous aerobic and anaerobic training 43 00:03:01,919 --> 00:03:04,560 Speaker 1: and it was five to six hours per week and 44 00:03:04,600 --> 00:03:08,720 Speaker 1: the results were pretty bloody stunning. Their VO two macs 45 00:03:08,960 --> 00:03:12,760 Speaker 1: increased by forty five percent, so went way above what 46 00:03:12,919 --> 00:03:17,400 Speaker 1: they were before they came in. Their stroke volume jumped 47 00:03:17,639 --> 00:03:21,960 Speaker 1: forty eight percent, and their cardiac output and returned to 48 00:03:21,960 --> 00:03:25,440 Speaker 1: it and actually even surpassed their baseline levels. And the 49 00:03:25,560 --> 00:03:31,000 Speaker 1: cardiovascular damage from complete rest was not just reversible, it 50 00:03:31,160 --> 00:03:36,600 Speaker 1: was reversible and actually went higher through targeted, consistent effort. 51 00:03:37,320 --> 00:03:40,880 Speaker 1: And remember this wasn't just a theoretical benefit. This is 52 00:03:40,920 --> 00:03:45,600 Speaker 1: actually a seismic shift in how heart attacks were treated 53 00:03:46,240 --> 00:03:50,080 Speaker 1: from their on no more prolonged bed rest after heart attacks. 54 00:03:50,560 --> 00:03:55,400 Speaker 1: This was the genesis of cardiac rehabilitation. And if we 55 00:03:55,560 --> 00:03:59,760 Speaker 1: fast forward thirty years, the researchers tracked down the same 56 00:03:59,760 --> 00:04:03,440 Speaker 1: thive men, now all still in their fifties, and they 57 00:04:03,480 --> 00:04:06,360 Speaker 1: tested them again. This time there was no bad rest. 58 00:04:06,440 --> 00:04:10,880 Speaker 1: They just wanted to examine how three decades of normal 59 00:04:11,040 --> 00:04:15,360 Speaker 1: aging had impacted their hearts, and to the researcher surprise, 60 00:04:15,800 --> 00:04:19,239 Speaker 1: their VO two max had only declined by twelve percent 61 00:04:19,440 --> 00:04:23,360 Speaker 1: in thirty years, and compare that to the twenty seven 62 00:04:23,440 --> 00:04:27,640 Speaker 1: percent crash after three weeks of bad rest. Now, what 63 00:04:27,760 --> 00:04:31,320 Speaker 1: probably happened was that training study that they did. That 64 00:04:31,400 --> 00:04:34,919 Speaker 1: they went through. The bed rest and training study probably 65 00:04:35,240 --> 00:04:38,520 Speaker 1: locked in for these guys the importance of fitness, and 66 00:04:38,600 --> 00:04:44,400 Speaker 1: so they probably had lifelong exercise and that's why their 67 00:04:44,440 --> 00:04:48,040 Speaker 1: hearts when they were in their fifties actually seemed a 68 00:04:48,040 --> 00:04:52,200 Speaker 1: lot better than what was the original thirty years of aging. Right, 69 00:04:52,800 --> 00:04:56,840 Speaker 1: But this time they actually trained these guys again, but 70 00:04:57,120 --> 00:04:59,320 Speaker 1: this was a bit of a gentler program, and it 71 00:04:59,360 --> 00:05:02,640 Speaker 1: was long. It was two hundred and fifty minutes a week, 72 00:05:03,160 --> 00:05:06,080 Speaker 1: and it was progressive overload. Right. They didn't start them 73 00:05:06,080 --> 00:05:08,560 Speaker 1: as hard as they did when they were younger. They 74 00:05:08,640 --> 00:05:13,160 Speaker 1: built it up over time. But again they got significant 75 00:05:13,200 --> 00:05:17,000 Speaker 1: gains their VEO two max roles fourteen percent, right, not 76 00:05:17,080 --> 00:05:19,560 Speaker 1: quite as much as in their youth, but that's that's massive. Like, 77 00:05:19,600 --> 00:05:22,360 Speaker 1: if you're in your fifties and you can increase your 78 00:05:22,440 --> 00:05:26,560 Speaker 1: VO two max by fourteen percent, that has a really 79 00:05:26,880 --> 00:05:31,360 Speaker 1: profound effect on your risk of all cause mortality. Now, 80 00:05:31,440 --> 00:05:36,039 Speaker 1: let's bring this study forward now into the future. Twenty eighteen, 81 00:05:36,279 --> 00:05:40,040 Speaker 1: the same research team and this was at Dallas. They 82 00:05:40,080 --> 00:05:45,400 Speaker 1: asked a big question, can you reverse cardiac aging in 83 00:05:45,440 --> 00:05:48,400 Speaker 1: the middle age, not with a late level training, but 84 00:05:48,480 --> 00:05:53,440 Speaker 1: with a doable, realistic, although reasonably vigorous exercise plan. So 85 00:05:53,560 --> 00:05:57,560 Speaker 1: what they did is they recruited sixty one healthy but 86 00:05:57,839 --> 00:06:02,920 Speaker 1: sedentary middle aged adult typical population and their average age 87 00:06:02,960 --> 00:06:06,520 Speaker 1: was fifty three. Half of them and were assigned a 88 00:06:06,560 --> 00:06:10,800 Speaker 1: low intensity stretching and yoga control right, So these were 89 00:06:10,839 --> 00:06:13,760 Speaker 1: the control group. They didn't do nothing, they were doing 90 00:06:13,880 --> 00:06:18,279 Speaker 1: low intensity exercise and the other half got a smart 91 00:06:18,480 --> 00:06:23,919 Speaker 1: structured training program. And this was two years and the 92 00:06:24,000 --> 00:06:26,880 Speaker 1: key ingredients of this program and I will send a 93 00:06:26,920 --> 00:06:28,720 Speaker 1: link to this if you want to really get in 94 00:06:28,760 --> 00:06:31,320 Speaker 1: and geek out, but essentially it was four to five 95 00:06:31,440 --> 00:06:35,279 Speaker 1: days of training per week and it started off with 96 00:06:35,640 --> 00:06:39,560 Speaker 1: moderate intensity aerobic work what we call zone two. Now 97 00:06:39,560 --> 00:06:42,440 Speaker 1: you may have heard of zone two. That's in terms 98 00:06:42,440 --> 00:06:46,520 Speaker 1: of heart rate training zones, and it's sixty to seventy 99 00:06:46,600 --> 00:06:50,080 Speaker 1: percent of your maximum heart rate. This is the bread 100 00:06:50,120 --> 00:06:54,800 Speaker 1: and butter of endurance training. And if you don't have 101 00:06:54,800 --> 00:06:57,400 Speaker 1: a heart rate monitor, you don't know your maximum heartbrate. 102 00:06:58,040 --> 00:07:01,200 Speaker 1: The easiest explanation of zone too is you can talk, 103 00:07:01,800 --> 00:07:04,760 Speaker 1: but you can't sing, right, So you should be able 104 00:07:04,800 --> 00:07:08,680 Speaker 1: to hold a conversation, but somebody should know if they're 105 00:07:08,720 --> 00:07:11,440 Speaker 1: talking to you on the phone that you're actually exercising. 106 00:07:11,640 --> 00:07:14,640 Speaker 1: If you can sing, you're in zone one. If you 107 00:07:14,720 --> 00:07:19,720 Speaker 1: can't talk in full sentences, you're in zone three or higher. Now, 108 00:07:19,800 --> 00:07:24,160 Speaker 1: this modern intensity aerobic work is really important because it 109 00:07:24,240 --> 00:07:28,920 Speaker 1: is very very beneficial for our mitochondria and gives us 110 00:07:28,960 --> 00:07:32,840 Speaker 1: what we call an aerobic base. And then they added 111 00:07:32,960 --> 00:07:38,520 Speaker 1: in high intensity intervals and specifically they used my favorite 112 00:07:38,640 --> 00:07:41,240 Speaker 1: protocol and the one that I'm actually using for my 113 00:07:41,320 --> 00:07:46,200 Speaker 1: cardiac rehab, and it's their Norwegian style four x four protocol. 114 00:07:46,400 --> 00:07:49,120 Speaker 1: So what you do is you go four minutes hard 115 00:07:49,680 --> 00:07:52,600 Speaker 1: and at the end of those four minutes you should 116 00:07:52,640 --> 00:07:55,480 Speaker 1: be at ninety to ninety five percent of your max 117 00:07:55,520 --> 00:07:59,240 Speaker 1: heart rate or a perceived exertion of nine out of ten. Right, 118 00:07:59,280 --> 00:08:01,520 Speaker 1: So you do that for four minutes. Then you have 119 00:08:01,760 --> 00:08:05,360 Speaker 1: three minutes of active recovery down to about zone two 120 00:08:05,680 --> 00:08:09,080 Speaker 1: just to count, so you're keeping moving but at low 121 00:08:09,120 --> 00:08:13,080 Speaker 1: intensity that three minute recovery, and you do four intervals, right, 122 00:08:13,120 --> 00:08:16,120 Speaker 1: So it's four intervals with three recovery it's twenty five 123 00:08:16,280 --> 00:08:20,440 Speaker 1: minutes in total. And then they added into this one 124 00:08:20,880 --> 00:08:26,160 Speaker 1: long weekly session of endurance training and importantly as well, 125 00:08:26,240 --> 00:08:30,320 Speaker 1: they did twice weekly all body strength training. Right, so 126 00:08:30,440 --> 00:08:36,119 Speaker 1: this wasn't brutal, but it was a pretty reasonable, vigorous 127 00:08:36,200 --> 00:08:39,240 Speaker 1: exercise program, and it was calculated and it paid off. 128 00:08:39,920 --> 00:08:43,360 Speaker 1: After two years of this training, their VO two max 129 00:08:43,400 --> 00:08:47,280 Speaker 1: increased by eighteen percent. Now, this is a massive improvement 130 00:08:47,840 --> 00:08:51,360 Speaker 1: in middle age. And like I said earlier on this, 131 00:08:51,640 --> 00:08:54,480 Speaker 1: if you're in your fifties and you can increase your 132 00:08:54,559 --> 00:08:58,040 Speaker 1: VO two max by eighteen percent, there's not much else 133 00:08:58,080 --> 00:09:00,640 Speaker 1: out there that you could do that would juice your 134 00:09:00,720 --> 00:09:04,840 Speaker 1: risk of all cause mortality as much as increasing your 135 00:09:04,920 --> 00:09:08,360 Speaker 1: view two march by eighteen percent. But there was a 136 00:09:08,559 --> 00:09:12,720 Speaker 1: deeper win here. Their hearts actually got younger. So when 137 00:09:12,760 --> 00:09:16,640 Speaker 1: they really dug into looking at how their heart was performing, 138 00:09:17,280 --> 00:09:22,240 Speaker 1: their left ventricular stiffness. So you're left ventrical, that's that 139 00:09:22,520 --> 00:09:25,160 Speaker 1: you think about that the rooms of your heart, if 140 00:09:25,200 --> 00:09:29,280 Speaker 1: you like you're left ventricle, is this important room? This 141 00:09:29,040 --> 00:09:32,120 Speaker 1: is this is where the heart, the heart or the 142 00:09:32,200 --> 00:09:36,560 Speaker 1: chamber that fills up with blood and then it squeezes 143 00:09:36,640 --> 00:09:39,200 Speaker 1: and that's when your heart beats and actually pumps the 144 00:09:39,200 --> 00:09:42,320 Speaker 1: blood throughout your body. So your left fend. The stiffness 145 00:09:42,320 --> 00:09:46,840 Speaker 1: of your left ventricle, essentially how rigid or elastic it is, 146 00:09:46,840 --> 00:09:51,160 Speaker 1: is really important. And in these guys, their left ventricular 147 00:09:51,240 --> 00:09:56,439 Speaker 1: stiffness drops significantly. That meant that the heart could relax better, 148 00:09:56,480 --> 00:09:59,640 Speaker 1: it could fill more efficiently, and it could pump more 149 00:09:59,679 --> 00:10:02,760 Speaker 1: blood per beat. Now this is really important. So with me, 150 00:10:03,400 --> 00:10:06,720 Speaker 1: when I had that dodgy aortic valve, a bicuspit valve, 151 00:10:07,320 --> 00:10:09,920 Speaker 1: what that meant was every time that blood pumped out 152 00:10:09,960 --> 00:10:14,920 Speaker 1: of the left ventricle, and because my valve didn't shut correctly, 153 00:10:15,000 --> 00:10:18,240 Speaker 1: over time, some of the blood came back in and 154 00:10:18,280 --> 00:10:21,760 Speaker 1: that stretched the left ventricle. Now I was lucky that 155 00:10:21,840 --> 00:10:26,480 Speaker 1: I caught it relatively early. If I'd have waited another 156 00:10:26,600 --> 00:10:30,439 Speaker 1: year eighteen months, my left ventricle would have got much 157 00:10:30,480 --> 00:10:34,080 Speaker 1: stiffer and also would have stretched to the point of 158 00:10:34,200 --> 00:10:37,480 Speaker 1: no return. And that's what we call heart failure. When 159 00:10:37,520 --> 00:10:39,920 Speaker 1: you hear of heart failure, that's what it is. You're 160 00:10:40,000 --> 00:10:43,640 Speaker 1: left ventricle is actually stretching to the part of no return, 161 00:10:43,720 --> 00:10:46,320 Speaker 1: and it gets really stiff and it just does not 162 00:10:46,480 --> 00:10:50,120 Speaker 1: work well. Now, what also happened in these people is 163 00:10:50,120 --> 00:10:53,560 Speaker 1: their stroke volume also went up. The amount of blood 164 00:10:53,600 --> 00:10:57,200 Speaker 1: that they could pump out with every heartbeat, right, which 165 00:10:57,240 --> 00:11:01,280 Speaker 1: is really important. The heart size actually increase, So this 166 00:11:01,440 --> 00:11:06,120 Speaker 1: is a physiological adaptation. And a result of all of 167 00:11:06,160 --> 00:11:10,040 Speaker 1: that is that the resting heart rate went down because 168 00:11:10,080 --> 00:11:13,600 Speaker 1: the heart, because it was more efficient, didn't have to 169 00:11:13,679 --> 00:11:17,560 Speaker 1: beat as often. In real terms, this meant that they 170 00:11:17,640 --> 00:11:21,400 Speaker 1: were fitter, they have more efficient and more youthful hearts. 171 00:11:22,000 --> 00:11:25,960 Speaker 1: And in the control group, they didn't have any change, 172 00:11:26,000 --> 00:11:29,400 Speaker 1: any positive change. In fact, their heart function decline because 173 00:11:29,440 --> 00:11:32,040 Speaker 1: remember this is a two year study and they were 174 00:11:32,040 --> 00:11:35,439 Speaker 1: two years older and they had that two years of decline. 175 00:11:35,720 --> 00:11:39,000 Speaker 1: So let's break this down really simply in Layman's terms. So, 176 00:11:39,080 --> 00:11:43,240 Speaker 1: when your heart becomes stiff, that left ventricular stiffness, it 177 00:11:43,360 --> 00:11:47,080 Speaker 1: loses its ability to relax and fill with blood efficiently. 178 00:11:47,720 --> 00:11:52,040 Speaker 1: That is a direct pathway to heart failure with preserved 179 00:11:52,040 --> 00:11:54,880 Speaker 1: dejection fraction. That's what we talk about, and that's an 180 00:11:55,000 --> 00:12:00,440 Speaker 1: increasingly common and stubborn form of heart failure, especially and 181 00:12:00,520 --> 00:12:04,880 Speaker 1: older adults. And here's the kicker that twenty eighteen studies 182 00:12:04,880 --> 00:12:09,880 Speaker 1: showed that this trajectory is not inevitable. If you intervene 183 00:12:09,920 --> 00:12:13,880 Speaker 1: in middle age, you can stop this stiffness from setting 184 00:12:13,920 --> 00:12:18,599 Speaker 1: in the heart remains plastic or changeable into your fifties 185 00:12:18,640 --> 00:12:22,880 Speaker 1: and beyond. Now, the same research group did another study 186 00:12:23,160 --> 00:12:26,200 Speaker 1: where they took people in their sixties and they trained them, 187 00:12:26,240 --> 00:12:30,560 Speaker 1: and they didn't see the same results, right, So part 188 00:12:30,600 --> 00:12:32,720 Speaker 1: of that conclusion was you got to get on this 189 00:12:32,840 --> 00:12:34,839 Speaker 1: when you're in their fifties. But actually, when you look 190 00:12:34,880 --> 00:12:38,800 Speaker 1: into the detail, they did admit that the training intervention 191 00:12:38,920 --> 00:12:43,079 Speaker 1: that they did in the sixties wasn't as comprehensive as 192 00:12:43,120 --> 00:12:45,360 Speaker 1: the training intervention in the fifties. So there's still a 193 00:12:45,400 --> 00:12:48,000 Speaker 1: little bit of a question. But what we do though 194 00:12:48,840 --> 00:12:52,280 Speaker 1: is as your heart ages, it like all tissues in 195 00:12:52,320 --> 00:12:56,800 Speaker 1: the body, they lose their elasticity, right, So what does 196 00:12:56,840 --> 00:13:00,000 Speaker 1: this mean. It means that a couple of things. Number One, 197 00:13:00,080 --> 00:13:04,520 Speaker 1: your heart remembers. It remembers that three weeks of doing 198 00:13:04,600 --> 00:13:08,880 Speaker 1: nothing can wreck you more than three decades of aging. 199 00:13:09,000 --> 00:13:12,040 Speaker 1: So we have to be moving if we want to 200 00:13:12,080 --> 00:13:16,240 Speaker 1: have a healthy heart. But it also means that consistent 201 00:13:16,480 --> 00:13:21,360 Speaker 1: smart exercise, especially when it includes a mix of baseline 202 00:13:21,360 --> 00:13:25,959 Speaker 1: aerobic zone two and high intensity interval training that doesn't 203 00:13:26,000 --> 00:13:28,920 Speaker 1: just increase your fitness. This is about cardiac uth. It's 204 00:13:28,960 --> 00:13:32,640 Speaker 1: about making your heart younger, and if your heart gives up, 205 00:13:33,040 --> 00:13:36,920 Speaker 1: it's all over, right, And we're not talking about marathons here, right. 206 00:13:37,280 --> 00:13:40,880 Speaker 1: That twenty eighteen study met the public health guidelines right, 207 00:13:40,880 --> 00:13:43,160 Speaker 1: one hundred and fifty to three hundred minutes a week, 208 00:13:43,600 --> 00:13:47,040 Speaker 1: with some of it high intensity interval trainings and strength training. 209 00:13:47,040 --> 00:13:50,680 Speaker 1: I think that's also important in this study. It is achievable, 210 00:13:50,679 --> 00:13:54,040 Speaker 1: it is sustainable, but you've got to do the work. 211 00:13:54,160 --> 00:13:56,920 Speaker 1: That's the key thing. So the big take home here 212 00:13:57,760 --> 00:13:59,719 Speaker 1: is if you're in your forties and your fifties, or 213 00:14:00,160 --> 00:14:03,560 Speaker 1: you're guiding or know somebody is, this is the moment 214 00:14:03,800 --> 00:14:07,120 Speaker 1: to get on top of this because the longer you wait, 215 00:14:07,280 --> 00:14:10,920 Speaker 1: the harder it actually becomes. And if you're younger, don't 216 00:14:10,920 --> 00:14:15,600 Speaker 1: be complacent because your heart can age really really quickly 217 00:14:16,160 --> 00:14:20,480 Speaker 1: with lack of movement. In the end, your heart actually 218 00:14:20,600 --> 00:14:23,400 Speaker 1: wants and needs to be challenged. It was built to 219 00:14:23,560 --> 00:14:27,480 Speaker 1: respond and it responds to your environment. If you do 220 00:14:27,680 --> 00:14:32,000 Speaker 1: very little, your heart age is super super quick. But 221 00:14:32,320 --> 00:14:35,240 Speaker 1: if you actually do do the training, your heart will 222 00:14:35,280 --> 00:14:40,000 Speaker 1: respond and it will get and can get younger, and 223 00:14:40,040 --> 00:14:43,400 Speaker 1: you just have to give it the right kind of push. 224 00:14:44,040 --> 00:14:48,240 Speaker 1: And I'll leave you with probably my favorite quote of 225 00:14:48,320 --> 00:14:50,480 Speaker 1: any research journal I've ever read, from the Journal of 226 00:14:50,520 --> 00:14:55,920 Speaker 1: Applied Physiology in twenty twelve by Professor Frank Booth, legendary 227 00:14:55,960 --> 00:15:00,480 Speaker 1: exercise physiologist. He said, the human genome has not changed 228 00:15:00,480 --> 00:15:04,880 Speaker 1: in over forty five thousand years. Their current human genome 229 00:15:05,440 --> 00:15:11,560 Speaker 1: requires and expects us to be highly physically active for 230 00:15:11,920 --> 00:15:16,400 Speaker 1: normal functioning, and that is certainly the case for the heart. 231 00:15:16,920 --> 00:15:17,800 Speaker 1: Catch you next time.