1 00:00:09,400 --> 00:00:12,920 Speaker 1: Hey, everyone, welcome to another edition of Wisdom Wednesdays. Today, 2 00:00:12,960 --> 00:00:16,120 Speaker 1: I want to wave together two important studies that, when 3 00:00:16,120 --> 00:00:19,160 Speaker 1: you look at them side by side, tell a really 4 00:00:19,239 --> 00:00:24,080 Speaker 1: powerful story about resistance training and the aging brain. The 5 00:00:24,079 --> 00:00:27,080 Speaker 1: first one is a recent randomized control trial published in 6 00:00:27,120 --> 00:00:29,800 Speaker 1: the journal guro Science and the title of it was 7 00:00:29,920 --> 00:00:33,640 Speaker 1: Randomized Control Trial of Resistance Exercise. 8 00:00:33,200 --> 00:00:35,000 Speaker 2: And Brain Aging Clocks. 9 00:00:35,600 --> 00:00:38,320 Speaker 1: And then the other one is something called the SMART 10 00:00:38,400 --> 00:00:42,360 Speaker 1: trial the Study of Mental and Resistance Training in Mild 11 00:00:42,440 --> 00:00:45,239 Speaker 1: Cognitive Impowerment. This is a pretty famous study. It was 12 00:00:45,280 --> 00:00:50,120 Speaker 1: a randomized, double blind, double sham control trial. That means 13 00:00:50,159 --> 00:00:53,199 Speaker 1: that there was a control trial that had a double 14 00:00:53,440 --> 00:00:56,840 Speaker 1: intervention that they thought was a useful book was actually 15 00:00:56,960 --> 00:01:00,840 Speaker 1: a sham or just nothing. And that was in people 16 00:01:00,960 --> 00:01:04,800 Speaker 1: who already were diagnosed with mild cognitive and permit. And 17 00:01:04,840 --> 00:01:06,919 Speaker 1: when you put these two studies together, you get something 18 00:01:07,080 --> 00:01:11,080 Speaker 1: really compelling. So let's start with the newer study on 19 00:01:11,200 --> 00:01:15,280 Speaker 1: the brain aging clocks. They took three hundred and nine 20 00:01:15,360 --> 00:01:18,800 Speaker 1: older adults in their ages were sixty two to seventy 21 00:01:19,080 --> 00:01:23,559 Speaker 1: and they randomized into three different groups. One was heavy 22 00:01:23,640 --> 00:01:27,119 Speaker 1: resistance training where they did three supervised sessions a week 23 00:01:27,720 --> 00:01:31,320 Speaker 1: and the next one was moderate intensity resistance training. They 24 00:01:31,319 --> 00:01:35,000 Speaker 1: did one supervised session and in two home sessions per week, 25 00:01:35,040 --> 00:01:37,679 Speaker 1: so still doing three per week. And the third were 26 00:01:37,840 --> 00:01:41,240 Speaker 1: a non exercise control group, and they followed them for 27 00:01:41,319 --> 00:01:44,560 Speaker 1: one year with a two year follow up afterwards, which 28 00:01:44,640 --> 00:01:49,840 Speaker 1: is really tells you a lot about the enduring benefits 29 00:01:49,880 --> 00:01:53,440 Speaker 1: of a short term in dimension. And they used resting 30 00:01:53,480 --> 00:01:59,360 Speaker 1: state functional MRI to estimate biological brain age and using 31 00:01:59,440 --> 00:02:03,480 Speaker 1: machine learning earning brain clocks, trained on over twenty four 32 00:02:03,560 --> 00:02:06,440 Speaker 1: hundred independent adults, so this gives us a really good picture. 33 00:02:06,960 --> 00:02:09,440 Speaker 1: And the key metric that they talked about was the 34 00:02:09,520 --> 00:02:14,200 Speaker 1: brain age gap, that's the difference between the predicted brain 35 00:02:14,320 --> 00:02:17,240 Speaker 1: age from the tests and chronological age. 36 00:02:17,400 --> 00:02:18,280 Speaker 2: And here's what happened. 37 00:02:18,680 --> 00:02:24,080 Speaker 1: Both moderate and heavy resistance training groups showed significant reductions 38 00:02:24,120 --> 00:02:27,840 Speaker 1: in brain age. Those who did the heavy resistance training 39 00:02:28,360 --> 00:02:32,440 Speaker 1: they showed a brain age of one point four years 40 00:02:32,680 --> 00:02:36,520 Speaker 1: lesser reduced at one year, the moderate training pretty much 41 00:02:36,520 --> 00:02:39,640 Speaker 1: identical one point three nine years less at one year, 42 00:02:39,960 --> 00:02:42,600 Speaker 1: and then with the heavy training at two years out 43 00:02:42,960 --> 00:02:45,919 Speaker 1: they had a reduced brainage of one point at four 44 00:02:46,080 --> 00:02:50,200 Speaker 1: so so actulutely the improvements actually got better and modern 45 00:02:50,200 --> 00:02:52,720 Speaker 1: training even got even better than that. They had two 46 00:02:52,760 --> 00:02:56,359 Speaker 1: point twenty six years reduction in brainage at two years, 47 00:02:56,560 --> 00:03:00,360 Speaker 1: and the control group no change at all. Now, this 48 00:03:00,560 --> 00:03:04,440 Speaker 1: wasn't just one brain readion lighting up. When they restricted 49 00:03:04,480 --> 00:03:08,880 Speaker 1: analysis to individual networks like the default mode. 50 00:03:08,639 --> 00:03:11,200 Speaker 2: Network or the motor network. 51 00:03:10,800 --> 00:03:14,200 Speaker 1: The effect actually disappeared. So what was clear from this 52 00:03:14,320 --> 00:03:18,840 Speaker 1: picture is this was a whole brain shift, a distributed 53 00:03:18,880 --> 00:03:24,040 Speaker 1: whole brain shift towards younger functional connectivity profile or in 54 00:03:24,160 --> 00:03:29,560 Speaker 1: Layman's terms, a better brain. They also showed increased prefrontal 55 00:03:29,600 --> 00:03:35,040 Speaker 1: connectivity and improvements in leg strength really strongly correlated with 56 00:03:35,120 --> 00:03:38,080 Speaker 1: reductions in brain age gap, and that's not a new association. 57 00:03:38,800 --> 00:03:40,920 Speaker 1: So here's the take on here is train the muscle, 58 00:03:41,040 --> 00:03:44,640 Speaker 1: shift the network, and slow the clock. So let's jump 59 00:03:44,680 --> 00:03:47,360 Speaker 1: to the smart trial. So this is a little bit 60 00:03:47,400 --> 00:03:49,160 Speaker 1: of an older trial, but a very famous one. They 61 00:03:49,200 --> 00:03:53,120 Speaker 1: looked at one hundred adults who already had mild cognitive 62 00:03:53,160 --> 00:03:56,920 Speaker 1: imperment right, so they are a high risk group for dementia. 63 00:03:57,960 --> 00:04:00,880 Speaker 1: On about six to ten percent of people progress to 64 00:04:00,920 --> 00:04:04,040 Speaker 1: dementia each year if they have mid cognitive impermit. So 65 00:04:04,080 --> 00:04:07,160 Speaker 1: the participants were randomized into four groups, one who did 66 00:04:07,280 --> 00:04:12,120 Speaker 1: progressive resistance training I adding load as they continued to train. 67 00:04:12,480 --> 00:04:15,520 Speaker 1: Another one did cognitive training, the sort of brain training 68 00:04:15,560 --> 00:04:17,840 Speaker 1: stuff that you see all over the place. The next 69 00:04:17,839 --> 00:04:23,000 Speaker 1: one did combined resistance training and cognitive training, and then 70 00:04:23,040 --> 00:04:26,520 Speaker 1: the fourth group had this double sham control again. Now, 71 00:04:26,760 --> 00:04:30,840 Speaker 1: the training in this group was high intensity progressive resistance 72 00:04:30,880 --> 00:04:33,359 Speaker 1: training two to three days a week for six months, 73 00:04:33,440 --> 00:04:35,880 Speaker 1: and then they had an eighteen month follow up. The 74 00:04:35,960 --> 00:04:39,200 Speaker 1: primary artcome that they were looking at was global cognitive 75 00:04:39,240 --> 00:04:44,560 Speaker 1: function using something called the ADAS COG. That's a standard 76 00:04:45,240 --> 00:04:47,480 Speaker 1: cognitive assessment scale for Alzheimer's disease. 77 00:04:47,600 --> 00:04:50,280 Speaker 2: Here's what they find for the resistance training group. 78 00:04:50,400 --> 00:04:56,160 Speaker 1: They significantly improved their ADAS COG at six months, and 79 00:04:56,200 --> 00:04:59,279 Speaker 1: they doubled the proportion of participants scoring in the normal 80 00:04:59,360 --> 00:05:03,640 Speaker 1: cognitive range, going from twenty four percent to forty eight percent. 81 00:05:03,720 --> 00:05:08,640 Speaker 1: Like that's huge, and it had improved executive function. And importantly, 82 00:05:08,760 --> 00:05:14,240 Speaker 1: they maintained both executive and global cognitive benefits twelve months 83 00:05:14,279 --> 00:05:19,360 Speaker 1: after stopping the supervise training. So this didn't just slow decline, 84 00:05:19,800 --> 00:05:22,240 Speaker 1: it actually moved the chunk of people back into the 85 00:05:22,360 --> 00:05:25,200 Speaker 1: normal range. And these are people with mild cognitive I permit. 86 00:05:25,680 --> 00:05:28,800 Speaker 1: What happened to the group who did the cognitive training alone, 87 00:05:29,160 --> 00:05:33,920 Speaker 1: very minimal effect, the mainly temporary and reductions in the 88 00:05:34,400 --> 00:05:37,839 Speaker 1: rate of memory decline. The group that did the combined 89 00:05:37,880 --> 00:05:42,640 Speaker 1: resistance and cognitive training, surprisingly, they find that adding in 90 00:05:42,680 --> 00:05:46,560 Speaker 1: the cognitive training blunted some of the resistance training benefits, 91 00:05:46,880 --> 00:05:51,560 Speaker 1: particularly for executive and global domains. Now, the author speculated 92 00:05:51,640 --> 00:05:55,880 Speaker 1: that this could reflect interference at the level of neural adaptation, 93 00:05:56,440 --> 00:05:59,560 Speaker 1: and that's pretty similar to how between our bodies. We 94 00:05:59,640 --> 00:06:02,480 Speaker 1: know that if you're doing lots of endurance training while 95 00:06:02,520 --> 00:06:05,480 Speaker 1: you're doing strength training, the endurance training can blunt the games, 96 00:06:05,520 --> 00:06:08,000 Speaker 1: and vice versa if you do both at the same time, 97 00:06:08,200 --> 00:06:12,599 Speaker 1: and so there seems to be specificity of adaptation in 98 00:06:12,640 --> 00:06:16,159 Speaker 1: the brain. Now, let's weave these two together and say 99 00:06:16,520 --> 00:06:18,479 Speaker 1: what does this mean for us. Well, the smart trial 100 00:06:18,560 --> 00:06:24,200 Speaker 1: shows that resistance training improves clinical cognitive outcomes in people 101 00:06:24,240 --> 00:06:27,640 Speaker 1: who are already showing in permanent and the brain clock 102 00:06:27,720 --> 00:06:32,040 Speaker 1: study shows that resistance training shifts biological brain aging trajectories 103 00:06:32,080 --> 00:06:35,400 Speaker 1: in healthy older adults. One measured one of the studies 104 00:06:35,400 --> 00:06:38,920 Speaker 1: meadured cognition, the other measured brain at network age, and 105 00:06:39,040 --> 00:06:43,520 Speaker 1: together they suggest something pretty damned important. Resistance training just 106 00:06:43,560 --> 00:06:48,599 Speaker 1: doesn't make you feel stronger, It actually modifies the underlying 107 00:06:48,720 --> 00:06:55,120 Speaker 1: biology of brain aging, and this translates into measurable cognitive improvements. 108 00:06:55,760 --> 00:06:58,480 Speaker 1: So let's have a quick chat about how these effects 109 00:06:58,680 --> 00:07:02,320 Speaker 1: happen across both studies and the broader research in this area, 110 00:07:02,320 --> 00:07:04,159 Speaker 1: which I kind of dug into a little bit in 111 00:07:04,200 --> 00:07:08,920 Speaker 1: my PhD. Several mechanisms likely converge, right, So it's not 112 00:07:09,000 --> 00:07:10,640 Speaker 1: one of these things, it's probably. 113 00:07:10,320 --> 00:07:10,880 Speaker 2: All of them. 114 00:07:11,240 --> 00:07:16,040 Speaker 1: The first is neurotropic signaling. Resistance training increases BDNF. You've 115 00:07:16,040 --> 00:07:19,640 Speaker 1: heard me talk about BDNF brain derived neurotropic factor, and 116 00:07:19,800 --> 00:07:25,280 Speaker 1: also IGF one. They are both important in synaptic plasticity 117 00:07:25,640 --> 00:07:30,240 Speaker 1: and resilience of your neurons, right, They protect them against damage, 118 00:07:30,280 --> 00:07:33,920 Speaker 1: they help to grow connections, and the smart study authors 119 00:07:34,240 --> 00:07:39,760 Speaker 1: specifically report IGF one and anti inflammatory pathways as plausible 120 00:07:39,920 --> 00:07:44,960 Speaker 1: mediators in mild cognitive impermit. The second proposed mechanism has 121 00:07:45,000 --> 00:07:48,080 Speaker 1: improved insulin sensitivity. You may have heard of me talking 122 00:07:48,120 --> 00:07:53,320 Speaker 1: about Alzheimer's disease or dementia being called type three diabetes, 123 00:07:53,600 --> 00:07:57,200 Speaker 1: and that's because insulin resistance is very tightly linked to 124 00:07:57,280 --> 00:08:03,720 Speaker 1: cognitive decline. Resistance enhances peripheral eye through the body and 125 00:08:04,040 --> 00:08:08,320 Speaker 1: likely central it's in the brain, and insulin sensitivity, so 126 00:08:08,400 --> 00:08:12,800 Speaker 1: you get those improvements. The third was reduced inflammation. We 127 00:08:12,880 --> 00:08:17,080 Speaker 1: know that chronic, low grade inflammation not only increases your 128 00:08:17,160 --> 00:08:22,360 Speaker 1: risk of many chronic diseases, but also accelerates neurodegeneration. Resistance 129 00:08:22,400 --> 00:08:28,200 Speaker 1: training reduces systemic inflammatory signaling through the release of myokines, 130 00:08:28,200 --> 00:08:31,120 Speaker 1: which you've heard me talk about before. These molecules that 131 00:08:31,160 --> 00:08:34,040 Speaker 1: are produced in contracting muscle that get into your bloodstream 132 00:08:34,360 --> 00:08:37,440 Speaker 1: and have effects on all of your organs, and more 133 00:08:37,480 --> 00:08:43,280 Speaker 1: intense muscle contractions drive myokine production higher. The fourth mechanism 134 00:08:43,520 --> 00:08:47,439 Speaker 1: is enhanced cerebral perfusion or blood flow to the brain. 135 00:08:48,040 --> 00:08:53,600 Speaker 1: That mechanical loading improves our vascular health and our endothelial function. 136 00:08:53,679 --> 00:08:58,120 Speaker 1: The enditheosales are what make up your cardiovascular system or 137 00:08:58,120 --> 00:09:01,240 Speaker 1: it shart certainly your veins and orderies and driving increased 138 00:09:01,240 --> 00:09:06,439 Speaker 1: efficiency in the cardiovascar system, and it improves nutrient. 139 00:09:06,160 --> 00:09:07,240 Speaker 2: Delivery to the brain. 140 00:09:08,040 --> 00:09:12,720 Speaker 1: And then the fifth is mitochondrial adaptation. The brain is 141 00:09:12,800 --> 00:09:16,800 Speaker 1: a very expensive tissue to run, uses twenty to thirty 142 00:09:16,840 --> 00:09:22,640 Speaker 1: percent of your total blood glucose and improved mitochondrial efficiency 143 00:09:22,640 --> 00:09:27,319 Speaker 1: in your neurons supports that neural network stability. And here's 144 00:09:27,360 --> 00:09:31,680 Speaker 1: the important conceptual link. So the brain clock study showed 145 00:09:31,720 --> 00:09:36,600 Speaker 1: distributed network level changes and the smart trial showed executive 146 00:09:36,640 --> 00:09:40,840 Speaker 1: and global function improvements. These are domains heavily dependent on 147 00:09:41,360 --> 00:09:46,040 Speaker 1: this distributed network integrity, how your brain is actually communicating 148 00:09:46,720 --> 00:09:50,920 Speaker 1: and particularly your prefrontal circuits. So it's the same networks, 149 00:09:50,920 --> 00:09:54,560 Speaker 1: but it's different measurement tools being used. So what's the 150 00:09:54,559 --> 00:09:59,480 Speaker 1: bigger picture here. Well, for years we've focused on brain training, games, 151 00:09:59,520 --> 00:10:04,160 Speaker 1: supplement and pharmaceutical agents, but here we have two very 152 00:10:04,240 --> 00:10:08,400 Speaker 1: well designed randomized control trials showing that two to three 153 00:10:08,520 --> 00:10:13,880 Speaker 1: structured resistance training sessions per week of moderate high intensity 154 00:10:13,880 --> 00:10:19,319 Speaker 1: with progressive overload can reduce biological brainage, improved global cognition, 155 00:10:19,760 --> 00:10:25,280 Speaker 1: enhance executive function, and potentially delayed dementia progression. So the 156 00:10:25,360 --> 00:10:28,320 Speaker 1: practical impiginations for us all is that we don't need 157 00:10:28,400 --> 00:10:32,400 Speaker 1: these exotic protocols and expensive supplements. Both of these studies 158 00:10:32,480 --> 00:10:37,040 Speaker 1: use supervised progressive resistance training modern to heavy loads major 159 00:10:37,120 --> 00:10:40,600 Speaker 1: muscle groups two to three sessions a week, and importantly 160 00:10:40,679 --> 00:10:44,080 Speaker 1: the Brian clock study showed modern intensity to be just 161 00:10:44,120 --> 00:10:46,440 Speaker 1: as effective as heavy intensity stuff. 162 00:10:46,520 --> 00:10:48,360 Speaker 2: No, it was different in the smart trial. 163 00:10:49,200 --> 00:10:52,200 Speaker 1: So final thoughts here is that the trajectory of the 164 00:10:52,240 --> 00:10:58,240 Speaker 1: aging of Ubrian is modifiable and mechanical loading of muscle 165 00:10:58,720 --> 00:11:03,360 Speaker 1: through resistance training appears to really influence the integrity of. 166 00:11:03,400 --> 00:11:04,520 Speaker 2: Your neural networks. 167 00:11:04,720 --> 00:11:09,040 Speaker 1: And it's not crystal clear that resistance training improves cognitive 168 00:11:09,040 --> 00:11:14,520 Speaker 1: performance in high risk individuals and shifts biological brainage in 169 00:11:14,600 --> 00:11:18,840 Speaker 1: healthy adults. So it's about training the muscle, strengthen the network, 170 00:11:19,040 --> 00:11:19,960 Speaker 1: preserve the mind. 171 00:11:20,480 --> 00:11:23,400 Speaker 2: Go lift heavy shit people. That's it for this week, folks, 172 00:11:23,600 --> 00:11:24,440 Speaker 2: catch you next time.