1 00:00:09,480 --> 00:00:12,840 Speaker 1: Hey everyone, welcome to another edition of Wisdom Wednesdays. Before 2 00:00:12,880 --> 00:00:15,760 Speaker 1: we get into the podcast, quick announcement. My new book, 3 00:00:15,840 --> 00:00:19,920 Speaker 1: The Hardiness Effect, How to Grow From Stress, Optimize your 4 00:00:19,960 --> 00:00:25,000 Speaker 1: health and live Longer, is now forcel on Amazon dot 5 00:00:25,040 --> 00:00:28,360 Speaker 1: Com or Amazon dot Com do au and it actually 6 00:00:28,360 --> 00:00:31,520 Speaker 1: has for a short period of time about a twenty 7 00:00:31,520 --> 00:00:34,519 Speaker 1: five percent discount, So now is the time to go 8 00:00:34,600 --> 00:00:39,720 Speaker 1: in and pre order The Hardiness Effect and get yourself 9 00:00:39,760 --> 00:00:43,240 Speaker 1: a bit of a discount. Now onto the podcast. Today, 10 00:00:43,400 --> 00:00:47,120 Speaker 1: we are going to talk about the interaction between exercise 11 00:00:47,440 --> 00:00:50,920 Speaker 1: and heat exposure. So some of you may know or 12 00:00:50,960 --> 00:00:55,240 Speaker 1: may have heard that getting in a sauna after doing 13 00:00:55,440 --> 00:01:02,720 Speaker 1: particularly resistance training can spike growth hormone by a significant 14 00:01:02,720 --> 00:01:06,240 Speaker 1: amount three to four fold increase, and some studies have 15 00:01:06,319 --> 00:01:11,760 Speaker 1: shown and a new study just out followed a bunch 16 00:01:11,800 --> 00:01:15,760 Speaker 1: of cyclists, male cyclists who were pretty fit. They had 17 00:01:15,760 --> 00:01:19,480 Speaker 1: an average VO two max of sixty middle leaders per 18 00:01:19,560 --> 00:01:22,520 Speaker 1: kilogram per minute, which is pretty damn fit. But it 19 00:01:22,560 --> 00:01:26,160 Speaker 1: was a randomized control trial and they all performed high 20 00:01:26,200 --> 00:01:30,440 Speaker 1: intensity interval training for three weeks and then did hot 21 00:01:30,480 --> 00:01:35,600 Speaker 1: water immersion after exercise. Now, some of the research has 22 00:01:35,640 --> 00:01:40,720 Speaker 1: suggested that getting into a hot bath for at about 23 00:01:40,800 --> 00:01:45,200 Speaker 1: forty degrees for twenty minutes can actually mimic the effects 24 00:01:45,280 --> 00:01:48,880 Speaker 1: of the sauna and spike growth hormone and lead to 25 00:01:49,440 --> 00:01:54,480 Speaker 1: better performance games after exercise. So let's dig into this study. 26 00:01:54,760 --> 00:01:58,680 Speaker 1: So they did nine high intensity interval training sessions over 27 00:01:58,720 --> 00:02:01,480 Speaker 1: three weeks, so that was three sessions per week, and 28 00:02:01,560 --> 00:02:05,280 Speaker 1: immediately after exercise, they took a thirty minute bath in 29 00:02:05,400 --> 00:02:08,679 Speaker 1: either hot water at forty two degrees centigrade which is 30 00:02:08,680 --> 00:02:13,240 Speaker 1: one hundred and eight degrees firenheit or thermonutral kind of 31 00:02:13,240 --> 00:02:17,400 Speaker 1: body temperature ish so thirty four degrees centigrade or seventy 32 00:02:17,560 --> 00:02:22,360 Speaker 1: five degrees fahrenheit. And before and after the interventions, the 33 00:02:22,480 --> 00:02:27,079 Speaker 1: researchers collected muscle biopsies. So these guys are pretty game. 34 00:02:27,400 --> 00:02:30,000 Speaker 1: I don't know if you've ever seen a muscle biopsy 35 00:02:30,080 --> 00:02:34,920 Speaker 1: or had a muscle biopsy, but they basically use a massive, 36 00:02:35,040 --> 00:02:40,120 Speaker 1: thick needle like device and take a pinch of your muscle. 37 00:02:40,440 --> 00:02:43,320 Speaker 1: That's about the size of a rice crispy or rice 38 00:02:43,400 --> 00:02:46,680 Speaker 1: bubble depending on what country you're in, So it's pretty 39 00:02:46,840 --> 00:02:51,280 Speaker 1: dam sore. But anyway, so these guys were donating a 40 00:02:51,320 --> 00:02:54,000 Speaker 1: little bit of their muscles to science, and what they 41 00:02:54,040 --> 00:02:58,040 Speaker 1: wanted to look at was the adaptations in the mitochondria. 42 00:02:58,880 --> 00:03:04,359 Speaker 1: And then the performed a time to exhaustion test and 43 00:03:04,720 --> 00:03:09,320 Speaker 1: a twenty kilometer time trial on a cycle orgometer, and 44 00:03:09,360 --> 00:03:13,960 Speaker 1: the time trial performance improved to a similar degree in 45 00:03:14,000 --> 00:03:17,640 Speaker 1: both the hot water and the thermal neutral water groups 46 00:03:17,720 --> 00:03:23,000 Speaker 1: during the study, whereas the mitochondrial adaptations were unchanged in 47 00:03:23,120 --> 00:03:25,639 Speaker 1: both groups. So this is a bit of a damp 48 00:03:25,760 --> 00:03:31,200 Speaker 1: squid in terms of this idea that going into a 49 00:03:31,280 --> 00:03:36,520 Speaker 1: sauna or exposing yourself to heat and can improve exercise adaptations. 50 00:03:36,560 --> 00:03:41,000 Speaker 1: But a couple of things to dig into. So firstly, 51 00:03:41,880 --> 00:03:45,400 Speaker 1: let's look at a big picture. So repeated heat exposure 52 00:03:46,080 --> 00:03:50,760 Speaker 1: that is sufficiently stressful to elevate core temperature and that's 53 00:03:50,960 --> 00:03:56,000 Speaker 1: critical actually results in a number of physiological adaptations, so 54 00:03:56,080 --> 00:04:00,360 Speaker 1: you get overall heat acclimation. But what actually happened is 55 00:04:00,360 --> 00:04:05,600 Speaker 1: there's their plasma volume. The amount of plasma increases or expands, 56 00:04:06,400 --> 00:04:09,600 Speaker 1: you get reduced heart rate and core temperature at rest, 57 00:04:10,080 --> 00:04:14,080 Speaker 1: and during exercise you get higher sweat output earlier onset 58 00:04:14,120 --> 00:04:18,320 Speaker 1: of sweating and increased amounts of hemoglobin or hemoglobin mass. 59 00:04:18,640 --> 00:04:23,840 Speaker 1: And that heat acclimation is something that athletes do, that 60 00:04:24,000 --> 00:04:28,719 Speaker 1: military guys do as well, and it can it has 61 00:04:28,760 --> 00:04:33,280 Speaker 1: been shown quite unequivocally to improve aerobic exercise performance in 62 00:04:33,360 --> 00:04:38,400 Speaker 1: hot environments, especially performance on time to exhaustion tests. Now, 63 00:04:38,720 --> 00:04:41,839 Speaker 1: on the other hand, and some studies have shown mixed 64 00:04:41,880 --> 00:04:46,520 Speaker 1: results with respect as to whether heat acclimation improves aerobic 65 00:04:46,560 --> 00:04:51,200 Speaker 1: exercise performance in normal environments, so when it's not too hot, 66 00:04:51,839 --> 00:04:55,800 Speaker 1: and according to a meta analysis, heat acclamation can improve 67 00:04:55,920 --> 00:05:00,320 Speaker 1: vot max to a small degree when testing occurs in 68 00:05:00,360 --> 00:05:04,040 Speaker 1: a temperate environment, so not that hot, and the magnitude 69 00:05:04,040 --> 00:05:07,159 Speaker 1: of improvement is greater when VO two max is tested 70 00:05:07,200 --> 00:05:09,359 Speaker 1: in a hot environment, which kind of makes sense because 71 00:05:09,360 --> 00:05:14,240 Speaker 1: you're adapting to the heat. Now, alow, VO two max 72 00:05:14,320 --> 00:05:17,880 Speaker 1: is a strong predictor of aerobic exercise performance, Several other 73 00:05:18,080 --> 00:05:23,480 Speaker 1: physiological factors also play a role, such as your lactate threshold. 74 00:05:23,560 --> 00:05:26,960 Speaker 1: So there's a whole heap of stuff of adaptations that 75 00:05:27,200 --> 00:05:30,320 Speaker 1: actually go on in a number of these different studies. 76 00:05:30,880 --> 00:05:36,320 Speaker 1: And you can induce this heat acclamation by either exercising 77 00:05:36,320 --> 00:05:40,800 Speaker 1: in the heat or exercising in a thermal neutral environment 78 00:05:40,880 --> 00:05:45,159 Speaker 1: and wearing a heat suit or thermal clothing. And it 79 00:05:45,200 --> 00:05:47,320 Speaker 1: can also be induced, and this is where this study 80 00:05:47,320 --> 00:05:50,680 Speaker 1: comes in through passive methods like sona bailing or hot 81 00:05:50,720 --> 00:05:55,679 Speaker 1: water immersion. So some of these adaptations occur pretty quickly, 82 00:05:56,240 --> 00:06:00,200 Speaker 1: such as plasma volume expansion that can take only three 83 00:06:00,279 --> 00:06:06,360 Speaker 1: or four days, but we know that some longer interventions, 84 00:06:07,360 --> 00:06:10,719 Speaker 1: generally about five weeks or so, are needed to increase 85 00:06:10,760 --> 00:06:15,600 Speaker 1: your red blood cell volume and hemoglobin mass. Now, although 86 00:06:15,839 --> 00:06:20,599 Speaker 1: it has been suggested that the different protocols whether you 87 00:06:20,720 --> 00:06:24,560 Speaker 1: do sauna post exercise, hot water post exercise, or you 88 00:06:24,800 --> 00:06:28,360 Speaker 1: exercise in the heat, although some of the previous research 89 00:06:28,440 --> 00:06:35,719 Speaker 1: has suggested that they stimulate similar adaptations, Ultimately, this study 90 00:06:36,200 --> 00:06:39,680 Speaker 1: didn't find a beneficial effect of the hot water immersion 91 00:06:39,800 --> 00:06:45,040 Speaker 1: on exercise performance. And one potential reason for this is 92 00:06:45,080 --> 00:06:49,960 Speaker 1: that the exercise tests were performed in a temperate environment, 93 00:06:50,240 --> 00:06:56,479 Speaker 1: and as discussed above, those adaptations and generally have the 94 00:06:56,480 --> 00:07:00,599 Speaker 1: biggest impact when you're exercising in hot environments. But there's 95 00:07:00,680 --> 00:07:05,760 Speaker 1: another thing that's really important here, and I think why 96 00:07:05,839 --> 00:07:11,120 Speaker 1: this study didn't enhance the exercise adaptations, and it's probably 97 00:07:11,120 --> 00:07:14,680 Speaker 1: because the protocol wasn't stressful enough. During the last five 98 00:07:14,720 --> 00:07:19,760 Speaker 1: minutes of hot water immersion, core temperature was approximately thirty 99 00:07:19,840 --> 00:07:24,120 Speaker 1: seven point eight degrees, which is about one hundred degrees fahrenheit. Now, 100 00:07:24,160 --> 00:07:28,520 Speaker 1: the evidence suggests that core temperature should be raised to 101 00:07:28,840 --> 00:07:31,880 Speaker 1: at least thirty eight point five degrees that's one hundred 102 00:07:31,880 --> 00:07:36,880 Speaker 1: and one point three degrees fahrenheit. So it was almost 103 00:07:36,440 --> 00:07:42,640 Speaker 1: a one degree centigrade, almost one degree centigrade lower than 104 00:07:42,680 --> 00:07:47,000 Speaker 1: it needed to be to maximize heat acclimation adaptations. And 105 00:07:47,080 --> 00:07:50,760 Speaker 1: here's the thing. Why all of this happens, or why 106 00:07:50,840 --> 00:07:56,400 Speaker 1: a lot of this happens, and particularly the changes are 107 00:07:56,440 --> 00:08:02,040 Speaker 1: the increased adaptations are because of stress response proteins, and 108 00:08:02,560 --> 00:08:06,560 Speaker 1: a lot of the research around SONA bathing is shown 109 00:08:06,960 --> 00:08:11,000 Speaker 1: that we get a lot of the positive adaptations, not 110 00:08:11,080 --> 00:08:14,160 Speaker 1: all of them, but we certainly get a lot of 111 00:08:14,240 --> 00:08:21,520 Speaker 1: positive adaptations because that heat can activate these stress response proteins. 112 00:08:21,520 --> 00:08:25,280 Speaker 1: These are my favorite proteins in the body, and they 113 00:08:25,320 --> 00:08:33,280 Speaker 1: are nature's agents of hardiness. So when you exercise vigorously, 114 00:08:34,400 --> 00:08:38,120 Speaker 1: or you are in the heat enough to increase your 115 00:08:38,120 --> 00:08:43,360 Speaker 1: core body temperature by about one degree, or you have 116 00:08:43,520 --> 00:08:48,400 Speaker 1: significant amounts of cold exposure, you will release these stress 117 00:08:48,400 --> 00:08:53,400 Speaker 1: response proteins, and in cold exposure you get both heat 118 00:08:53,400 --> 00:08:56,200 Speaker 1: shok proteins and cold shock proteins, whereas in the heat 119 00:08:56,440 --> 00:09:00,560 Speaker 1: you only get heat shock proteins. But these proteins actually 120 00:09:01,040 --> 00:09:06,719 Speaker 1: stimulate lots of different adaptations, and it's basically nature's way 121 00:09:06,760 --> 00:09:10,680 Speaker 1: of going Jesus, this is a stressful environment, so we 122 00:09:10,920 --> 00:09:15,520 Speaker 1: had better toughen up the body in case we encounter 123 00:09:15,640 --> 00:09:20,000 Speaker 1: this environment again. And I think this is probably why 124 00:09:20,040 --> 00:09:24,240 Speaker 1: this study didn't show the improvement that other studies have, 125 00:09:24,880 --> 00:09:29,960 Speaker 1: because they didn't increase the core body temperature. And I'm 126 00:09:30,000 --> 00:09:34,440 Speaker 1: not sure how quickly they got into the water, but 127 00:09:35,000 --> 00:09:38,600 Speaker 1: I certainly know. So to add a bit of color 128 00:09:38,640 --> 00:09:42,400 Speaker 1: onto this, when I was deciding whether or not to 129 00:09:42,600 --> 00:09:46,040 Speaker 1: have when I got my sauna, whether or not to 130 00:09:46,080 --> 00:09:50,080 Speaker 1: have a traditional finish sauna or an infrared sauna, what 131 00:09:50,200 --> 00:09:52,400 Speaker 1: I was really interested in. I did a whole heap 132 00:09:52,440 --> 00:09:55,280 Speaker 1: of research on the heat shot proteins and find that 133 00:09:56,040 --> 00:09:59,520 Speaker 1: generally you need to stimulate or increase your core body 134 00:09:59,559 --> 00:10:05,360 Speaker 1: temperature by about one degree or to that threshold of 135 00:10:05,559 --> 00:10:09,360 Speaker 1: thirty and a half degrees in order to stimulate those 136 00:10:09,360 --> 00:10:13,880 Speaker 1: heat chock proteins. And I find that actually the infrared 137 00:10:14,080 --> 00:10:18,360 Speaker 1: sauna did increase my core body temperature by one degree 138 00:10:18,440 --> 00:10:20,680 Speaker 1: if I was in it for at least twenty minutes, 139 00:10:20,720 --> 00:10:24,959 Speaker 1: and it was on seventy degrees and especially it did 140 00:10:24,960 --> 00:10:28,200 Speaker 1: it quicker after exercise. I won't go into too much 141 00:10:28,240 --> 00:10:32,679 Speaker 1: detail about how I worked, how much my core body 142 00:10:32,720 --> 00:10:36,160 Speaker 1: temperature was increasing. I will just leave that to the imagination. 143 00:10:36,800 --> 00:10:40,040 Speaker 1: So there's a couple of other three week studies, and 144 00:10:40,080 --> 00:10:44,160 Speaker 1: it's important to compare the time that looked at post 145 00:10:44,200 --> 00:10:48,120 Speaker 1: exercise sauna building. And one had male football players in 146 00:10:48,160 --> 00:10:51,200 Speaker 1: Spain that did their usual training program and then performed 147 00:10:51,240 --> 00:10:54,640 Speaker 1: three forty minutes ona sessions a week, and it was 148 00:10:54,679 --> 00:10:57,160 Speaker 1: four bouts of ten minutes each with a little break 149 00:10:57,160 --> 00:11:01,040 Speaker 1: in between, at a temperature of a undred degrees centigrade 150 00:11:01,080 --> 00:11:03,320 Speaker 1: or two hundred and twelve degrees firenheat, which is pretty 151 00:11:03,360 --> 00:11:07,600 Speaker 1: damn hot. And they had that as I said, they 152 00:11:07,600 --> 00:11:09,280 Speaker 1: did ten minutes and the end a few minutes of 153 00:11:09,280 --> 00:11:11,760 Speaker 1: recovery and then ten minutes again and at the end 154 00:11:11,800 --> 00:11:14,640 Speaker 1: of the study there are time to exhaustion and their 155 00:11:14,679 --> 00:11:17,320 Speaker 1: VO two max improved more in the solar group than 156 00:11:17,360 --> 00:11:21,680 Speaker 1: the control group. And another study which has a crossover design, 157 00:11:21,679 --> 00:11:25,080 Speaker 1: which is what you do that the first, whether it's 158 00:11:25,120 --> 00:11:28,400 Speaker 1: the control group some one group does that first and 159 00:11:28,440 --> 00:11:30,640 Speaker 1: the other does the intervention and then they switch over. 160 00:11:31,040 --> 00:11:33,800 Speaker 1: This is probably the best design that there is that 161 00:11:33,880 --> 00:11:36,720 Speaker 1: had meal distance runners and triathletes sit in the sauna 162 00:11:36,840 --> 00:11:39,400 Speaker 1: at ninety degrees centigrade or one hundred and ninety degrees 163 00:11:39,440 --> 00:11:43,920 Speaker 1: fahrenheit immediately after exercise for about thirty minutes, result in 164 00:11:43,920 --> 00:11:48,520 Speaker 1: a total of about thirteen SAW sessions during the study 165 00:11:48,880 --> 00:11:50,960 Speaker 1: and the end of the study their performance on a 166 00:11:51,000 --> 00:11:54,680 Speaker 1: time to exhaustion test was better when they incorporated the 167 00:11:54,800 --> 00:12:00,079 Speaker 1: SAWA sessions. And there are actually numerous studies that show 168 00:12:00,480 --> 00:12:07,400 Speaker 1: that you get improvements in our increased stimulation from strength 169 00:12:07,440 --> 00:12:11,200 Speaker 1: training if you then get into the sauna afterwards. But 170 00:12:11,640 --> 00:12:14,800 Speaker 1: it would appear in all of these studies that you 171 00:12:14,920 --> 00:12:19,520 Speaker 1: need to increase your core body temperature by about one degree. Now, 172 00:12:19,800 --> 00:12:23,640 Speaker 1: if you are working out intensely and then you get 173 00:12:23,679 --> 00:12:27,600 Speaker 1: straight into the sauna, you're going to have a quicker 174 00:12:27,679 --> 00:12:31,360 Speaker 1: impact on your core body temperature. So, particularly if you've 175 00:12:31,400 --> 00:12:34,040 Speaker 1: worked out to the point where you're sweating and you're hot, 176 00:12:34,600 --> 00:12:38,560 Speaker 1: and then you just jump into the sauna, some of 177 00:12:38,559 --> 00:12:42,320 Speaker 1: the research shows that about twenty minutes in there at 178 00:12:42,440 --> 00:12:46,160 Speaker 1: any degree centigrade. Now that's in a traditional sauna, and 179 00:12:46,240 --> 00:12:48,840 Speaker 1: I think you get away with less in a near 180 00:12:48,880 --> 00:12:51,679 Speaker 1: infrared sona because, as you may be aware, that heats 181 00:12:51,720 --> 00:12:55,600 Speaker 1: you from the inside as well, and I certainly sweat 182 00:12:56,280 --> 00:12:59,959 Speaker 1: much more at the same temperature on an infrared song 183 00:13:00,200 --> 00:13:02,840 Speaker 1: than I do on a traditional finished sona. But anyway, 184 00:13:03,240 --> 00:13:06,640 Speaker 1: it would appear to be that you gotta increase that 185 00:13:06,840 --> 00:13:10,840 Speaker 1: core body temperature by one degree in order to get 186 00:13:10,880 --> 00:13:16,440 Speaker 1: those real additional effects on a muscle mass and muscle 187 00:13:16,480 --> 00:13:21,240 Speaker 1: stimulation from strength training, but on this one improvements and 188 00:13:21,320 --> 00:13:26,120 Speaker 1: exercise performance if you're doing cardiovascular training. So the take 189 00:13:26,160 --> 00:13:28,120 Speaker 1: on with all of this is that if you want 190 00:13:28,160 --> 00:13:32,800 Speaker 1: to optimize your adaptations to exercise, whether that's through strength 191 00:13:32,800 --> 00:13:39,000 Speaker 1: training or cardiovascular training, both sauna and hot baths would 192 00:13:39,040 --> 00:13:42,040 Speaker 1: appear to be a good way to actually do that 193 00:13:42,360 --> 00:13:44,760 Speaker 1: if you have access to them and you have the 194 00:13:44,840 --> 00:13:47,440 Speaker 1: time to be able to do that. That's it for 195 00:13:47,480 --> 00:13:49,280 Speaker 1: this week, folks, Catch you next time.