Transcript
0:00 Hello, thank you for joining us for another episode of Hypertrophy Past and Present. Chris, how are you doing today? I'm doing well, thanks, Jake. Uh although this is the second podcast that I've recorded, so I'm definitely uh in that professional podcaster zone at the moment. >> Ah, there you go. I didn't even know that. There we go. We've talked for an hour and you didn't even tell me that you've done another podcast today. >> [laughter] >> To be fair, a large chunk of that talk was trying to figure out how on earth we're going to explain the routine that you've got to show us today. Yeah, that's true. And we kind of got to the end of the conversation saying it doesn't matter.
0:37 As long [laughter] as you guys are going to get the idea. You'll know exactly why it doesn't matter in a in a few moments time. So, today's episode is kind of in part an extension to last week's episode. So, last week we covered drop sets and we talked about how they kind of were done in this not called drop set way, but what is effectively a drop set in the silver era and were done really intelligently, to be honest. Not that we're saying everyone should go out and do them, but it did make a lot of sense the way that they were being programmed. Now, off the back of that episode there's been a lot of conversation, questions, confusion around kind of why they would work, how these rest periods work, shouldn't we just do longer rest periods, where is it better than doing longer rest periods? And people kind of not really understanding having a lot of questions over how this rest period thing kind of works. And I think that's fair enough because ultimately what we're doing is playing with different types of fatigue and fatigue mechanisms and and that will shift kind of what that rest period is or isn't doing. And it's confusing to to hear people say, "Well, long rest periods are always better, but clusters can kind of work and drop sets can kind of work." And it seems paradoxical. So, we're going to talk a little bit more about rest periods specifically today.
1:48 >> [clears throat] >> And it's a conversation I'm actually really excited to be having because I actually think it's a topic that is not just misunderstood, but I actually think the general recommendation is not a good recommendation in most cases. It's one of those ones where I feel like the recommendation is kind of let's just give like a you know, a middle ground recommendation and it kind of doesn't work for anything. And I think you really we should be pushing it one way or the other and what people are generally saying doesn't make sense. So we'll jump into that.
2:16 But before we do, I have a >> [laughter] >> I have a workout routine for you. So [snorts] bear with me. This is going to be a challenge in and of itself. This is Serge Nubret. Now, he was a a bodybuilder obviously. He started competing right at the tail end of the silver era, but then he won his titles and and you know, Mr. Universe in in the mid to late 70s. So you know, well and truly into the golden era.
2:43 Um, I think we can you know, fairly confidently say that he was enhanced. I don't know if he ever talked about anabolic use, but obviously competing at a time where that was rife. Now, I'm not going to go into more detail about Serge. You're welcome to look him up if you would like, but this was one of his routines which I think he called it faster paced training. I don't know I don't know that's the term he coined or just what it was referred to.
3:06 But essentially between these sets, he was taking very very very short rest periods. We're talking somewhere in the realms of like 15 to 30 seconds and just smashing out these sets. Now, this routine was done six days per week. So it is a a three-way [clears throat] split and then repeated. But he was actually training multiple times per day as well. So I'll explain that as we go. Now, broadly speaking, assume that every exercise I mention was done for five to 10 sets and there are some exceptions to that which I will mention. But if I don't say how many sets they were done usually for five to 10 sets of 15 repetitions. Okay?
3:48 So we're talking tremendous amounts of volume here. So day one, we have and these first exercises are actually done for 15 sets, okay? So, we've got leg extension and leg curl, 15 sets each. Then, we go into a hack squat. Again, we're dropping down to our standard 5 to 10 sets. Uh standing calf raises, seated calf raises, donkey calf raises, and then we finish with up to 2,000 situps. Suggesting that this is his AM workout, and we've already got 60 plus sets.
4:21 Now, that's not it for day one. He then, later on in the mid-morning, did shoulders, and he did 10 sets of behind-the-neck barbell press, and then he did lying one-arm dumbbell lateral raises and standing dumbbell lateral raises, both for 10 sets each. So, we've got another 30 sets, we're up to about, I don't know, 90 sets or so now for day one. And then in the evening, we're not done yet. We've got chest, and we've got 20 to 30 sets of bench, and [sighs] we've got straight-arm pullover and then dumbbell flies. So, we're concluding with uh what are we now? 120, 130 sets, thereabouts for day one.
4:59 >> [laughter] [gasps] >> And then day two, we have uh standing calf raises. We did calves yesterday, don't forget, but we're going to do them again. We've got standing calf raises, seated calf raises, and donkey calf raises, each for five sets. And doing abs again for another 2,000 or so situps. Now, day two, we've only got one more installment. So, we only have a two-parter here, and in the evening, we've got 12 sets of AMRAP for chin-ups.
5:26 And then we've got uh lat pulldown for 12 sets, and a reverse grip pulldown for another eight sets or so. So, what are we? 20, 30, 45, a bit over 45 sets for day two. So, nothing really compared to today one. And then our last workout in this little cycle is we have our we start with our situps. So again, give or take 2,000 situps. And then we got arms. Now, for the arms, it was a barbell curl and a lying triceps extension. I think he did these as a superset. I think they were five sets each.
6:06 And then a dumbbell concentration curl with a cable push down for five sets each. So, what? 10 sets triceps, 10 sets biceps, 20 sets in total. You know, it almost seems reasonable in contrast to everything else. So that third day was only what is that? 20 20 sets in total? 21 sets or however many sets he did for his his um his situps. And then he would repeat that. And start again next day. And he had one day off, uh but you know, this this little cycle was repeated twice per week.
6:37 So, I don't know if anyone listening has given this workout routine a go. If you have, please message me. Drop me a message in on Insta and let me know how how long you did it for and what your results were like and if you're bedridden now for the rest of your life, but I'd be interested to hear. Okay, Chris. I'll unleash you. Unmute yourself. What do you think? >> [laughter] >> So, I've got all kinds of things floating around in my head right now about this.
7:05 Um I mean, obviously, I'm not going to deconstruct it because that would just be silly. I mean, it's so far away from anything that you know, we would see physiologically as sensible and also in line with Silver Era training that it's quite clearly, you know, um just completely insane. Um but equally, it's really interesting because I think that it's probably more volume than even the most committed um devotees of high volume training today would actually go for. Um so, this is really interesting. So, I think that if somebody is running around at the moment saying, "Oh, you know, I think high volume is the answer and you know, it's just random the fact that people trained in a different way with much lower volume before the introduction of anabolics, then I would be really tempted to give them this routine and say, "Well, if you think that high volume is the best way to achieve gains, then why don't you do this program?"
8:04 >> Here you go, it's written for you. It's already right there. Just go for it, you know, and just come back and and see what happens. >> [laughter] >> Um but yeah, I mean, like jokes aside, it is um you know, quite clearly um a very good example of um a routine that only really appeared after the introduction of anabolic steroids. So, basically from the dawn of time to, you know, like 1950-1955, everybody trained with much lower volumes. Um you know, and they weren't dividing their workouts out into different sections and doing different things on different days. They were basically just doing the same workout pretty much more or less um three times a week. And then suddenly with anabolics getting introduced, we get this completely different approach to training, which has got absolutely insane amounts of volume um and also in the context of what we're talking about much shorter rest periods.
9:04 So, generally speaking in the uh silver era, much longer rest periods. What we've got here, obviously, much, much shorter rest. And you actually need it cuz you physically won't get through the um things in the time. You won't get you won't finish before your next workout. Yeah, I think that's probably accurate. I mean, you actually have to kind of treat this as an endurance sport, really, um to get through the repetitions. Um yeah, so um it really, when I look at this, it almost doesn't look like strength training because you have to use such short rest periods and you'd have to reduce the um the actual load so much that it would be kind of sort of very far removed from what we would expect to be uh normal strength training weights, I think. Especially in somebody of this level of strength.
9:53 So, yeah. Not really I don't I don't really want to go any further and start deconstructing the program and say, "Oh, like the exercise selection was different or it cuz it's just it's just [snorts] mad." I mean, it's not >> here you think makes sense? So, obviously the fact that he is actually still training uh every muscle group um more than once a week is an indicator is an indicator that he is still drawing on that silver era kind of um model.
10:27 Um I mean, if he'd been really kind of separating everything out and doing a full uh kind of body part split across the week, I think he would have tipped over into the next era of bodybuilding practices. Um but yeah, I mean, we've still got uh 2 days a week. I'm I've been chuckling about actually been chuckling a little bit about 2 days versus 3 days and 1 day again cuz it keeps coming around. Everyone wants to talk about frequency all the time at the moment.
10:55 Um and so, every so often somebody will have another go and say, "Oh, there's no evidence about this or there's no evidence about that." or whatever the buzzword is for the day. And I'm like, you know, there isn't any evidence for two times a week that is better than one time a week. So, if if you really want to pin your kind of colors to that two times a week mask, you you are going to be struggling because at least on the evidence-based side of things, if that's where you want to go, then there isn't really any way you can you can point to and say, "Oh, and this study clearly shows that two is better than one." I'm like, "Well, you know, not sure it does show that, to be honest."
11:29 >> It very much feels like just hedging their bets, doesn't it? It's like, well, I don't I don't honestly believe one time is just as good and I don't want to do three times, so I'm just going to kind of say that this middle ground is what's best, which I feel is the most disingenuous part of the argument cuz people are saying it is best. Yeah, I know, and it's it's there's there's just nothing out there. The only The only The only kind of data point that people can really um sort of uh identify is the Korea um uh sort of uh analysis of multiple studies. It's not a true meta-analysis.
12:03 Um and and that really was sort of aggregating data in a way that I have said before I don't really think is valid. Um there isn't actually a single long-term training study that shows that two better than one. So, um you can't really kind of argue that two is the kind of the panacea, the best thing to do cuz it just hasn't got any evidence to to support that. Um so, and then of course, what you then have to do is start of uh analyzing things mechanistically, in which case you end up in my model and then uh it becomes three times or three and a half times a week anyway. Um but yeah, so I was chuckling a little bit about this this kind of two times a week because that seems to be recirculating. But yeah, we have here a higher frequency than we do in other uh kind of um uh sort of maybe golden era or later programs.
12:52 >> Um so, that is that is cool. Um I don't have um sort of anything particularly interesting to say about exercise selection. Um it's not horrible and it's not amazing. Um you know, it's obviously making use of the fact that the machines exist, uh which is a huge advantage. Um but more than that, I don't think it's um you know, anything particularly special. I do think it's interesting that in almost every muscle group here, they he still has at least two exercises per muscle. Yeah, that's fine. Yeah.
13:29 And generally the like the exercise section is not awful. Um like it's usually kind of different enough within those exercises. Yeah, like for me if I if I were to take these exercises, even if I had had to keep them on the same days that he has them, I'd reduce it all down to single sets or two sets and >> like you could still end up with an okay program. Yeah, you're right. Yeah, I guess I'm just being a little bit harsh cuz of just the sheer insanity of the calf raises. I mean, it's just how many calf raise variations do you want? But, you know, other than that, yeah, you're right. It is it is relatively it's relatively sensible exercise selection.
14:11 But again, as I say, a lot of that just comes from the fact that we've got, you know, the machines to be able to do that. So, you know, you've got knee extensions and leg curls and suddenly your life becomes a lot easier. So, you now got ways to train those two joint muscles without difficulty. Um yeah, and yeah, you know, to be fair, back exercises are good. He's got behind the neck pull down, which is going to give him pretty wide grip, so he's going to be definitely in the front of plane.
14:37 Um you know, so yeah, he's got wide grip and probably narrow grip pulling in now, which is all you really want. I don't think there's any shrugging in here, but um you know, if you're using anabolics, then you probably wouldn't need to do shrugs anyway. Yeah. >> [sighs and gasps] >> Uh yeah, goodness. Um I just wonder 20 15 to 30 sets for some of these exercises like bench. 30 sets of bench with 15 repetitions. Surely one would be just using the bar at the end. And if he's got 30 seconds, 20 seconds between sets, goodness me.
15:14 Yeah, yeah. I don't know if there's video footage of Serge doing these workouts. I'll have to look, but I would just be shocked if if doing any appreciable load at all. I think it to Yeah, but again, I think it it would depend a little bit on on um individual. I mean, some people are going to be much more able to withstand and maintain uh reps over multiple sets than other people, but >> Yeah. Yeah, I would be completely cooked. I would just be I would be abs- I I wouldn't even be moving the bar. I'd be I'd be needing to use a broomstick.
15:45 [laughter] You wouldn't wouldn't be able to unrack it. No, I wouldn't be able to unrack it. >> [laughter] >> Okay. So, last week we we did dive a little bit into some of these different fatigue mechanisms that are occurring within a workout when we were talking about drop sets, but we'll give a little bit of a refresher here. I assume that's where we're going to move on to now. Rest periods, yeah. Let's do it. That's your That's your cue to tell us about >> Okay.
16:13 >> [laughter] >> I will do the mechanisms. I will do that. Um so, um yeah, basically if we start at the beginning, um when we're doing strength training sets and we're taking rest periods between sets, then what's happening is that fatigue mechanisms are building up during the set itself, and then those fatigue mechanisms then dissipating in that following rest period. So, if we take a very long rest period, then what we're doing is we're allowing all the fatigue mechanisms to dissipate before we start the next set. If we take a shorter rest period, then uh we're allowing those fatigue mechanisms to remain when we obviously do start the next set. Now, the important thing to remember is that fatigue is the objective measurement outcome. So, we get a reduction in the number of reps. So, if you go from uh set one, set two, set three, and you see a reduction in reps of, I don't know, couple of reps on the first to the second, and another couple of reps on the second to the third, the objective reduction in performance, you could, if you wanted to, you could to count it as number of reps lost. So, you don't have to say fatigue is a percent percentage loss in strength or percentage loss in whatever, you could just say it is this many reps lost or, you know, on average I lose 2.3 repetitions. That is a totally valid way of measuring your fatigue if you want to do that.
17:32 Uh all it has to be is an objective external measurement and it doesn't have to be percentage terms. It could be, as I say, uh just rep number terms. Um but, the fatigue mechanisms are um under the surface. Now, generally speaking, what you've got are mechanisms of fatigue that will dissipate uh quickly and mechanisms of fatigue that will dissipate uh slightly more slowly. So, what you can find is that if you um finish a strength training set and then leave a short rest period, you're more likely to have a larger number of different fatigue mechanisms still present in comparison with if you leave a longer rest period. And if you leave it long enough rest period, then really the only thing that can possibly be left over that point is um some of your calcium accumulated fatigue, which in the context of a single workout will pretty much just be excitation-contraction coupling failure.
18:22 >> [snorts] >> Won't really be anything else in the context of a single workout. Not not usually. Um so, um basically, what we can do is we can look at a strength training set and we can say, "Okay, what fatigue mechanisms are actually occurring?" Um and then, how quickly do they dissipate? And then, if I start my next set before some of them have finished dissipating, then, you know, what's the effect going to be? So, generally speaking, when we look at strength training sets, we divide the fatigue mechanisms up into firstly, two categories being central and peripheral.
18:52 So, central nervous system fatigue mechanisms and peripheral mechanisms. And then, we further divide those into another two categories each. So, in the central nervous system, you've got super spinal and spinal. And then, in the periphery, you've got metabolite-related and calcium accumulated. Okay. In terms of the CNS, when we we about super spinal and spinal, super spinal obviously means above the level of the spine, so happens in the brain. The brain mechanisms of fatigue are just governed by the psychobiological model of fatigue. So, basically, it just says that if you can feel a sensation which is negative, it contributes to your perception of effort. And that means that you're going to hit your maximum tolerable perception of effort at a lower level of motor unit recruitment than you would do if you didn't have those sensations present. So, if I do a strength training set, and the classic example is I get out of breath. So, if I get out of breath and I'm still out of breath and feeling those negative sensations in my body as I get to the start of my second set, I am not going to achieve as high a number of reps in my second set as I would do in the first set simply because I'm adding on that additional discomforting sensation of feeling out of breath to my second set.
19:57 And therefore, I'm hitting my maximum tolerable perception of effort earlier than I would do or at a lower level of central motor command than I would do in a another situation without that sensation being present. So, that's a classic example of super spinal safety. Going to give you another thing as well, but yeah. >> On that, people that I I don't know if you've seen a lot of people are saying, "Oh, no, it's not actually about perception of effort anymore. We were wrong about that all along or you were wrong about that."
20:20 >> [laughter] >> And and there's some this this sort of push of this narrative that oh, there's actually no research that supports that and it's all peripheral fatigue. Is there Do you want to say anything to that or is that a whole can of worms? Um it's not really a can of worms. It's just that's people dismissing research that they haven't read. I mean, there is a uh large amount of research showing that we hit um maximum Sorry, that we hit we arrive at muscular failure without hitting maximum levels of um motor unit recruitment. Um I mean, this actually goes back a very long way. I mean, I've got I was actually just looking at some very early research just um kind of um over the weekend um where they were trying to extrapolate to figure out exactly where the um true levels of um kind of maximum muscle force really are because depends on how you approach the extrapolation as we increase motor unit recruitment increase force production they generally go pretty pretty linearly but as you approach the top end it starts to bend a little bit so you start to get a little bit of a difference um but fundamentally there is I mean you can literally pick almost any voluntary activation study that's ever been done and you'll see that somebody is sitting in a dynamometer with and we've been through this before I mean sitting in the dynamometer and they sitting in the dynamometer and you've got maximum levels of stability because you're strapped in I mean it is above and beyond what you're going to get in a machine exercise in the gym so you're totally strapped in you're using a single joint and a single limb um exercise so it's usually either over flexion or it's knee extension and you're strapped in and you're only using one limb and it's single joint and even in that scenario you're pushing as hard as you can for 3 seconds even in that scenario you've still got a gap between what you're actually capable of physically exerting with your maximum effort and what your muscle is capable of doing if you give it a little bit of help with some extra electrical stimulation so that tells you that there are muscle fibers that are not being used and in the case of the force deficit that you're going to see in untrained people it's going to be like 20% in the case of a quadriceps now this really important to realize that that 20% is a force deficit so what we're saying is that if I electrically stimulate a little bit more of the muscle then I'm going to get potentially theoretically another 20% of force output but the important thing to realize is that that 20% is being created by muscle fibers that aren't hypertrophied you know so the reality is you're massively underestimating what that could really do if you could hypertrophy those 20 per- 20% they are fast twitch fibers, they're potentially going to be really big. You could get way more than that. So, the reality is you're comparing your 80% is hypertrophied fibers. Now, sure at the bottom end they're highly oxidative, so they're not very big and that's that's by the by, but what I'm saying is you could actually get a lot more out of that top bit of the muscle if you're capable of actually growing those fibers. So, you're not really comparing like with like. So, again we must be underestimating. So, if you want to extrapolate that scenario and say, you know, okay what would the voluntary activation uh deficit look like in a strength training exercise in the gym? Well, straight away you're not doing sing- you're not doing fully stable situations because you're not strapped in. You're not doing um kind of single joint single limb stuff most of the time. So, straight away your voluntary activation deficit is going to jump much much bigger. You're going to not be able to activate a lot more fibers than you would do in that compared to that dynamometry situation.
23:55 So, [snorts] you know, the reality is that the simple existence of the dynamometry research and then extrapolating that to a strength training context tells you that not only is your voluntary activation deficit absolutely there, which means that you must be hitting failure for another reason, not a peripheral reason, um or uh not only that is true, it's actually going to be even bigger than what you see happening in the literature because we would expect lack of stability and using more muscle mass to create larger amounts of voluntary activation deficits than we actually see in the in the dynamometry literature. So, um honestly, I think the first hurdle that people need to cross if they want to argue that muscular is entirely a peripheral concept, they need to cross the observation that in the dynamometry literature there are huge voluntary activation deficits. That's the first hurdle they need to cross. The next hurdle they need to cross is that, you know, we would expect voluntary activation deficits to be even bigger in the context of strength training than they are in the dynamometry literature.
24:49 So, even if you're seeing like a couple of percent for a biceps uh curl in a dynamometry situation, it's going to be bigger than a couple of percent in a strength training situation straight away. But as I say, in the lower body muscles, the bigger muscles, it's way bigger than that anyway. Yeah, and I don't think that there would ever be a way of explaining away motivation as well. The fact that Well, and then then you've got all this stuff where you can instantaneously increase performance. So, if I'm if somebody's doing a strength training set, and I mean, I've given this example 100 times, but if if I'm standing, you know, behind the the leg press, and I jump out with a kind of fistful of dollars, and I say, you know, get an extra rep and I'll give you all of this money, you know, somebody is going to find the motivation to get that extra repetition.
25:32 I mean, you can do it in another situation. I'm just giving a an amusing example, but you know, you can give somebody motivation that they're instantaneously able to hit higher levels of um repetition numbers of repetitions. Well, if peripheral fatigue is the only thing that is making a difference, how did you get that extra repetition? It's not possible. And it's not just, you know, kind of those kind of motivations. You can do motivation in a whole bunch of different ways. You can have motivation, you know, like I just provided an example there.
25:59 You can have just people shouting encouragement. You can have um so sort of um social facilitation, which is where you have like people around just presenting, you know, kind of a a group um around you while you're doing some work. That generally tends to motivate people. Um you know, and you can have um a goal orientation um of motivation, where you kind of like maybe have a graph on a computer where they can see what level their force is output at, and they can try and beat the number that they got last time. I mean, there's all kinds of different ways that you can do I mean, you can do that as a logbook based approach as well, but the whole point is that all of those um those uh kind of motivational uh cues instantaneously change the number of reps that we can do. And the other side also is true. So, like what we've just talked about there is changing your maximum tolerable perception of effort by directly increasing um your tolerance to discomfort. Basically, what you're saying is I'm only normally prepared to tolerate this level of discomfort, but if I were to be motivated, then I would increase the amount of effort that I'm prepared to tolerate, and then suddenly you increase the number of reps you can do because you can increase the level of motor unit recruitment that you can create. But equally, even if you keep motor unit recruit not motor unit recruit, even if you keep um the maximum tolerable perception of effort the same, if you've got any negative sensations and you remove those, then instantaneously you then create an increase in the number of reps you can do cuz you're relieving some of that negative sensation. And the classic example of that, of course, is carb uh mouth rinsing. So, if somebody is doing a workout and they uh haven't uh you know, consumed carbs in the immediate uh kind of uh vicinity of that workout, and you ask them just to uh swill some uh kind of uh sugary drink around and then spit it out, instantaneously they can now do more reps than they were able to do if you hadn't been given them that sugary drink, even though they haven't consumed any of it. So, there's no fuel change.
27:57 Um it's literally just the brain going, "All right, okay, we've got some extra fuel there, so I can be a bit more relaxed on the whole kind of fearing the loss of um you know, fuel inside the body, so I I can dial back on the sensation, which is our input for telling us that we are running out of fuel." If I take that away because I know that I've probably got some fuel coming in from somewhere else, then I can I can relax a little bit. There's no sens- no no sensation. So, all of these things really tie together and show us that, you know, we are hitting muscular failure because um you know, we're hitting maximum tolerable perception of effort, which is perfectly in line with what happens in longer durations of exercise. So, I think, you know, some people are going, "Oh, well, you know, the psychobiological model of Teague was, you know, intended I'm using my words very, very carefully here, intended for use in the context of endurance sport.
28:48 Yes, it was. But, it was actually tested um in the strength training context. Because if you look at the studies that have gone into figuring out how the psychobiological model of fatigue works, they use biceps curls. They use biceps curls to figure out how the sensation of innovation works, which is the signal coming from the motoneur- coming from the um motor cortex, which produces motoneuron recruitment. But, it also produces a sensation of um effort related to the motoneuron recruitment signal. Well, that was tested in strength training context. So, yeah, the the the intention behind the work that was done on the psychobiological model of fatigue was for use in endurance exercise, but it actually was tested in strength training context, even though it wasn't intended for use in endurance ones.
29:29 Um Yeah, so that's sort of where I was on the um muscular failure things. So, we've got a super spinal that you've just discussed there. You mentioned the the calcium ion related fatigue previously. I had one question on that. So, you said >> Before we do that, can I can I can I group them together and do uh all the CNS ones first? So, um the reality is that spinal CNS fatigue is not very uh complicated. So, we can just very quickly outline it. All it is is a desensitization of the motoneurons in the spinal cord to the motoneuron recruitment signal. So, you send recruitment down the spinal uh cord motoneurons, and once you start doing that, it starts to resist you. That's all that happens.
30:06 So, essentially, you start out with a certain level of sent motor command, and as you send more and more and more of it down the motoneurons, uh you start to get less getting through to the muscle. And that basically creates the same effect as super spinal CNS fatigue, except it's not the sensation, it's linked to the desensitization of the motoneurons. In terms of the dissipation of these things, the dissipation of super spinal tracks the sensation going away. So, if you're like breathing hard like 3 minutes later, you do a set of squats, 10 squats, whatever, and you're still breathing hard several minutes later, that sensation is telling you that you've got super spinal CNS fatigue present. In contrast, you can't really see that with spinal CNS fatigue.
30:47 It's just there, and it decays very very rapidly, 30 seconds or so, and most of it's gone, but it tends to have a bit of a long tail sitting there in the background that can kind of does last for a couple of minutes if not, you know, longer after the set has been completed. So, what we've got there is two very very different forms of CNS fatigue mechanism both leading to the same output, which is a reduction in motor unit recruitment, and we'll come back to that later on cuz it's critically important, but fundamentally actually working in different ways and having just different dissipation trajectories. So, as you write as you rightly said a minute ago, that leaves us then with the peripheral ones, which are metabolic related and calcium related.
31:29 Okay, so now I've got a question on spinal. So, both super spinal and spinal CNS fatigue, the magnitude of that is going to be driven by obviously not just this, but one of the component variables will be number of repetitions, right? So, if we're looking at spinal CNS fatigue, then ultimately the duration of that set is going to to have an impact. So, even though someone's not feeling the effects of spinal CNS fatigue, if someone were to do say a single repetition compared to a set of 20 or even an isometric set, then it's going to have it's going to take a varying amount of time for that to dissipate, yes?
32:08 Yeah, so broadly speaking, the total um uninterrupted time that you have been contracting a muscle for is going to be the primary determinant of your spinal CNS fatigue. Once you have interruptions, then you can obviously because of the very fast recovery of that particular type of fatigue mechanism, then you tend to start seeing a different effect. So, if you compare like a sort of reasonably not a long isometric, but like even 10-15 second isometric, then you'd see a lot more spinal sensitivity than that than you might expect from the equivalent duration of dynamic repetitions. Because with dynamics, you actually have these little breaks between each repetition. Um but fundamentally, when we're looking at normal strength training, then broadly speaking, the higher the rep range, the more spinal sensitivity you're going to get. And the reality is that because sensations tend to do the same thing, they tend to build with repetitions as well. You tend to have both CNS fatigue mechanisms tracking rep ranges pretty closely. So, this is one of those interesting things that long-time followers will know that CNS fatigue during workout pretty much kind of increase in line with rep range.
33:22 And most people in the fitness industry think it's the opposite. They think that heavy loads create CNS fatigue, and it just doesn't do that. It's just not how it works. Yeah, but both types of CNS fatigue that we're talking about both types, exactly. Both types, yeah. Um if someone were to do, say, a longer isometric, a 20-second isometric, would you still say that a good chunk of that spinal CNS fatigue would dissipate within 30 seconds, or might that push it even higher?
33:46 So, I think the dissipation rates would still be um I think you'd still see a relatively fast dissipation. Um I think really what you're you're you're kind of losing out there is that you know, toward the end of that that isometric, you're not really getting what you think you're getting. That's the problem. Okay, so you think it's worse within the set rather than after? >> Yeah, I do. I don't I don't think the I don't think it's cuz there's no real incentive for spinal CNS fatigue to stick around. Uh I mean, it's highly protective during the actual contraction itself, but I don't think there's a lot of incentive for it to hang around afterwards.
34:22 If you're doing a single repetition, or or a double or triple, you know, low repetitions, then presumably say so we're saying, okay, a lot of spinal CNS fatigue is dissipating quickly. You've done a low rep set. There's no way you're entering another set, even if you had a very short rest period, with more spinal CNS fatigue than if you were just to do a single moderate rep set. Right? Like if spinal CNS fatigue is driven by the duration of the contraction, then [clears throat] a set of 10 surely will always be producing more spinal CNS fatigue at the end of that single set, like towards the end of it, than even if you did two sets of triples with a shorter rest period, if you're just looking [clears throat] at spinal CNS fatigue, right? Sure. That makes sense?
35:06 Yeah, so I mean, the thing is, yeah, putting breaks into your set is going to limit both super spinal and spinal, really. Um I mean, as long as you Yeah, I mean, if you if you did say, um you know, a 10 rep max, and you compared that with, um you know, so as a straight set all the way through, and you compared that with a cluster format where you broke that up into, say, I don't know, four sets of three, um and you might and with the same kind of uh load, and you ended up pretty much hitting failure at the end of that, then your spinal CNS fatigue would be lower at the end, even though you've done more repetitions with the cluster format, because you'd have these breaks in between, quite substantial breaks in between. So, the really the spinal CNS fatigue would probably only be the magnitude of the last three reps, more or less.
35:55 Um super spinal-wise, I think it would be a more of a muchness between the two, because if you're hitting failure at the end of your final cluster, then you're probably in a more or less the same kind of place, as long as your your rep range is the same fundamentally, same 12 rep max or 10 rep max, what Sorry, 10 rep max what as the example. Uh you're probably going to be in the in the same kind of place as as regards the super spinal, but yeah, I think you'd have less less spinal in that in that context. I never thought about that.
36:22 >> [laughter] >> Yeah, I think that's quite interesting. I actually think there's something in that in terms of how we program. I'm going to think about that more afterwards. Now, earlier you mentioned if you did a set and you waited a long period of time, let's say 10 minutes, and you did another set, then the fatigue that is still present there is showing you that the calcium ion related fatigue and excitation-contraction coupling failure. Now, my question there is is there any value if if post-workout fatigue is predominantly driven by muscle damage, which is driven by calcium ion fatigue or calcium ion accumulation, then could one use that as a proxy for how much muscle damage they might be experiencing? If someone were to do a workout and then say an hour later come back and and train one [clears throat] of those exercises, they could theoretically be using that to to actually see to an extent. Obviously, it's like it'll be hard to quantify, but how much muscle damage might be might potentially occur due to the effect of the calcium ion fatigue, yeah?
37:17 Yeah, I mean, I think really anything 20 minutes onwards is probably going to give you the same information, more or less. Um the I mean, obviously, if you have created a decent chunk of muscle damage, then you'll have a secondary muscle damage effect over the course of the day, and it'll start to get worse rather than better. But, broadly speaking, if you look at the static stretching fatigue studies, cuz obviously the only type of um long-lasting um long-lasting is not the right word. Um the only type of fatigue that static stretching produces that lasts more than a few minutes has got to be calcium ion related fatigue. It can't be anything else. So, if you if you kind of look at that, generally speaking, you do see at 20 minutes, you do see static stretching producing fatigue. And it's a pretty much a flat line. So, you create some fatigue with the static stretching. Yes, there's a little bit of neural stuff going on, but >> [snorts] >> you know, broadly speaking, the only thing that lasts is going to be that calcium ion related fatigue effect from the stretch.
38:13 You know, allowing the stretch-activated ion channels to open, you get calcium ions flowing into the fiber, and then you get excitation-contraction coupling failure. And that pretty much is more or less static over 20 minutes following the stretch. So. Okay, so if someone was convinced today just experienced stacks of muscle damage, they damage very easily, then you could you could >> Yeah, you could simply do a set, give it 20 minutes, don't do anything else, come back to a set, and you'll see the amount of change you experience in it.
38:41 >> So, the interesting thing is you could you could do a test on one day where you do a normal rest period like say 3 minutes for 4 minutes, whatever. And you could see how many reps you lose doing that. And then you could do a completely different experiment on the next workout, and you could do a 20-minute rest period. And as long as you're not doing other stuff in between and creating an exercise order effect, then yeah, you could see whether the fatigues were the same. If the fatigues were the same, so let's say you did 10 reps in the first set and then seven reps in your second set, and it didn't matter whether you'd done, you know, kind of a 3-minute rest period or a 10-20 minute rest period, then that would tell you that you were extremely susceptible to calcium-related fatigue, and you weren't really getting anything else. Um I don't think that would be I think I think that would be very unusual, but it would it would tell you that that was what was happening.
39:29 Okay, good. I think there's a couple of interesting things there. So, moving on to there's other peripheral fatigue then that we haven't covered. Yeah, so basically you've got two types. You've got the And And when I when I say type, I'm grouping these. So, this is this podcast is not really supposed to kind of take people from, you know, like uh sort of completely not knowing anything about how fatigue mechanisms work to having a complete detailed, you know, list of every single fatigue mechanism. Beyond that, then my Patreon is probably where you need to go. But broadly speaking, we've got categories or groups of fatigue mechanism, calcium-related and then metabolite-related. And that's just kind of descriptive. It's what they are. So, obviously the metabolite-related fatigue mechanisms are produced by metabolic processes. Calcium-related fatigue mechanisms are produced when calcium ions are put into the muscle fiber in response to the activation or the stretch. I mean, either of those two things.
40:23 So, [snorts] metabolite related fatigue mechanisms, generally speaking, we tend to focus on two. We tend to focus on the hydrogen ions, which is also called acidosis, and we tend to focus on phosphates. So, broadly speaking, um when we look at acidosis, acidosis has been um a topic of intense interest in uh fatigue for very, very many decades. There was a lot of confusion, and this is going to trip a lot of people up. So, just as a very quick, a kind of a side, um the hypertrophy uh research community wasn't really interested in how fatigue worked until I came along and started saying, "Actually, you need to know how fatigue works cuz otherwise nothing makes any sense." And the reason I wanted to make uh kind of emphasize the importance of fatigue is because fatigue can, as we talked about earlier, affect motor unit recruitment. And if you can't hit the high level of recruitment, then you can't activate the fibers you want to train. If you can't activate those fibers and train them, you can't grow them. Um similarly, if you look at calcium related fatigue, it does reduce uh it does reduce the mechanical tension of the single fiber. So, you've got these two things that are important for hypertrophy, which is high recruitment and a single fiber tension, both being negatively affected by fatigue. So, I kind of pointed out that you need to know this stuff if you want to actually understand how strength training is um stimulating muscle growth.
41:39 Um but before I really did that, everyone was just like, "Well, you know, fatigue is complicated." And and wave your hands in the air and forget about it. Um but it actually is really, really important that we understand what's going on. But there are two groups of mechanisms. You've got the calcium related fatigue, which reduces mechanical tension of the fiber. And then you've got metabolites that really don't do that. Now, if you look at the history of um the study of acidosis, you will run into a number of um roadblocks pretty quickly.
42:05 And the reason for that is because um the way that acidosis has been studied has varied over the decades and the main thing that's varied a lots of things have varied in the context of how it's studied, but one of the main things that's varied is the temperature at which the muscle fibers are kind of tested. And the problem is that acidosis seems to behave quite differently depending on the temperature that you are keeping the muscle fibers at. So, if you keep them at way below physiological temperatures, they tend to produce slightly different effects compared to when you measure them at normal kind of body temperatures.
42:40 Also, another thing that's very different is that the We we talked before about how fatigue can be anything that's objective to the performance of the body. So, in the context of muscle fibers, often they measure force production. Now, the really annoying thing about acidosis is that it doesn't really change force production that much. It actually primarily changes shortening velocity. And that's really then going to cause problems when you start looking at trying to comparing when you're trying to compare different studies in the literature and you're like somebody's used a power measurement or somebody's used a force measurement and like suddenly you're going to get really really different results depending on what you're actually measuring because you're trying to measure fatigue in the context of manipulating metabolites around the muscle fiber, you're going to get very different results depending on what the room temp So, room temperature.
43:30 You're going to get very different results depending on what the temperature is around the muscle fiber and also on what your actual fatigue measurement is. Um that being said, it does look like the most uh kind of clear picture what's going on is that metabolites are primarily slowing down shortening velocities rather than actually changing the mechanical tension that the fibers can produce that much. And the best example I can give of this in the context of acidosis is that um the the the the way that acidosis works is very similar to the way that cold temperatures work. So, if you kind of been outside when it's really cold and you let your hands get a little bit cold, then you what you'll notice is that your grip strength isn't really that different, but your speed of movement of your fingers is incredibly slow. And that's basically because the temperature, the air temperature, is slowing down the rate at which you can um use the reactions, the metabolic reactions inside the muscle fibers, and allow you to um move in the direction you want to go in. Now, ultimately, that isn't really changing mechanical tension as much as most people think it is. It really is primarily just slowing down the speed which you can shorten the muscle fibers.
44:47 And as a result, the metabolic related fatigue, especially in the case of acidosis, is not actually altering the amount of mechanical tension that you can generate, it's just slowing down the fiber. Now, of course, the other thing that happens is as you slow down a muscle, cuz you've obviously got lots of muscle fibers working in parallel with each other. If you slow down the muscle fiber shortening velocity of some of your muscle fibers, then the whole muscle slows down. Even the fibers that weren't necessarily, you know, kind of experiencing the same degree of fatigue, are now going to experience a slower movement velocity because everything else is slowing down. So, what you end up with is applying a higher level of tension simply because of the force velocity relationship. Now, this is kind of getting into the stimulating rep kind of model, which you know, isn't really what I wanted to kind of get into too much today. We'll do that in another episode, but fundamentally, when we look at a strength training set approaching failure, what we're going to see is that slowing down of the muscle fiber shortening velocity, but we're not really going to see much of a reduction in mechanical tension. We're primarily, at least not from metabolites, we're primarily going to see um an increase due to the force velocity relationship.
45:53 Now, yeah, if you have a lot of calcium available, you can start creating a negative effect on tension, but primarily, if it's just metabolites, whether it's acidosis or phosphates, uh it doesn't really seem to matter that much. You will actually end up with a relatively kind of minimal negative impact on the mechanical tension that you're needing to produce the stimulus for hypertrophy of those muscle fibers. Now, you've grouped those together. Is there conditions which will lead to more of one versus the other?
46:23 Not really. I mean, acidosis will happen earlier. So, you'll hit you'll hit acidosis much much earlier than you will phosphates. But, phosphates have kind of a slightly slower kind of rate of development for various reasons. So, fundamentally, yeah, it's going to be the acidosis that is earlier, but I don't think we would see anything particularly manipulating that in one direction or the other. I mean, they're just pretty straightforward processes that happen the same way. And in terms of calcium ions?
46:54 In terms of calcium ions, you've got a number of factors that do make quite a big difference. So, we said before you've got two factors that drive calcium ion accumulation. One is activation and the other is stretch. So, with activation, as you approach failure, you're going to get obviously kind of marked increase in the amount of calcium ion accumulation as you activate more muscle fibers. Um So, you've also got a duration dependent phenomenon. So, the more repetitions you do, the more activation you're going to be experiencing for a longer period of time, and more calcium ion accumulation you're going to get. So, broadly speaking, rep range, volume, and proximity to failure kind of going to drive activation related calcium ion accumulation. And then on the stretch side, obviously, stretch position, so whether it's a um uh stretch position exercise or contract position exercise, and then obviously, um whether you've doing anything different in the eccentric phase. So, you can kind of start from either no eccentric phase, a normal eccentric phase, a very slow eccentric phase, or a an eccentric overload, and it will grade upwards in terms of calcium ion accumulation across that spectrum.
48:02 So, that's all the different fatigue mechanisms in this context we need to understand, yeah? Yeah, I mean that's basically the fatigue mechanisms as they're occurring. What we have to remember then is that if we reduce recruitment because of spinal CNS fatigue and it's still reduced when we start the next set, we have a problem in terms of the amount of hypertrophy we can stimulate in that second set. It's going to be reduced cuz the number of fibers that are activated and can experience hypertrophy is reduced. Now, importantly, this does two things. Firstly, it reduces the total hypertrophy you're going to get from that set in the context of the training program you're doing. But, if you're repeatedly doing most of your sets with that subdued level of recruitment, then your long-term growth capacity now is going to be lower because if you're not hitting enough Say, for example, say for example, you're doing a body part split program and your first set is the only one where you hit your highest levels of recruitment. Every other set, because you're doing one of these programs like we've talked about today, Yes, you do 15 seconds of bench, you do 15 seconds between sets. Your first set you hit higher >> is the only one where you Right, you are literally doing one set per week as far as the top muscle fibers in your muscle are concerned. They are not going to then be still growing or maintaining that growth that you've provided stimulating this for them at the following workout next Monday or even, you know, whenever. I mean, before that at some point they'll sort of have come back to their previous size. So, you are not going to maintain that from week to week to week if you're just doing one workout per week of 30 sets of bench or whatever silly number we can think of. So, So, yeah.
49:38 >> Serge's case, when he's doing it twice a week, he may have been maintaining that assuming that the recovery >> Yeah, the recovery was there. Yeah, [laughter] and she probably wasn't. So, yeah, basically the other sets that you do after that first one are going to be done with lower levels of recruitment, so they're never really going to be able to provide that same stimulus to that set of fibers that were hit at the very top end of the motor unit pool. So, the thing about recruitment is it actually creates a slightly different effect from just saying, "Oh, I get less hypertrophy because I'm, you know, fatigued." Well, hang on a minute, it's not just about less hypertrophy across the muscle. It's like, where is it happening? You're actually completely canceling out, you know, a number of fibers and saying they are not participating in the next strength training sets. On the peripheral side, you know, obviously we've got slightly different things going on. With the metabolites, they're largely kind of irrelevant. They do create a reduction in exercise performance, but they're not really creating a negative effect in terms of mechanical tension, not not meaningfully. Calcium ions are. So, the example I I said when we were talking about how we're going to stick to this conversation earlier, I said, "My favorite example for this is to compare a normal strength training set or sequence of sets."
50:53 Like, for example, you could say I'm going to do some hip thrusts. So, you could do like three sets of hip thrusts. You're going to see there's going to be um change in performance from set to set to set in that context. If you use shorter rest periods, then you're going to get a bigger drop in reps. But, the reality is that because it's a contract position exercise and it's a strength training exercise, and if you're using slightly heavier loading, you are going to end up with most of that being metabolic related. Most of the overall fatigue.
51:22 In contrast, if I were to do, say, an eccentric exercise, now to do multiple sets of eccentric exercise, now to do, say, a Nordic curl, then you'd be getting a lot of calcium ion related fatigue in that scenario, and you'd see a very different situation happening. In that second scenario, you'd be getting calcium ion accumulation, it would stay with you and reduce the single fiber tension. And that would then lead to huge reductions in the stimulus for hypertrophy in the subsequent sets. This is why if you look at the dose responses of strength training to of hypertrophy to strength training volume, you get a relatively kind of sort of interesting non-linear curve with strength training, but you get a much flatter curve with eccentric training. And this because your subsequent sets are basically annihilating the ability to produce mechanical tension on the single fiber level with the calcium ion related fatigue mechanisms that you get from the stretched kind of or the stretch of the fibers opening the stretch activated ion channels allowing the calcium ions into the fibers. So, very very different situations depending on the type of strength training you're doing. And this highlights the difference in the two fatigue mechanisms. So, I actually want to break that down further cuz I think this is going to be really valuable for people to hear. So, let's actually compare different conditions, different scenarios. So, let's say someone is doing a a low repetition set of a contracted position exercise. Yeah.
52:49 And they're doing short rest periods. Yeah. What are the main types of fatigue mechanisms that are going to accumulate in that scenario? Compared to compare that then to long rest periods. So, if you're doing like a hip thrust is the example I gave to start with and then maybe do a biceps curl example or something like that later on. If [snorts] we start with a hip thrust example, you are you are doing a multi-joint exercise. So, you are going to have sensation related kind of fatigue as in super smart fatigue happening.
53:23 But if you're doing heavy loads, you're not going to get an enormous amount of that and you're not going to get an enormous amount of spinal CST either. Basically, if you're doing say a set of five hip thrusts, most of your fatigue is actually going to be metabolic related. Now, this is one of those things that I say and people kind of either nod or they just kind of freak out. If they're nodding, it's because they probably haven't kind of put it two and two together and realized that everybody else in the fitness industry thinks that metabolic fatigue happens more so with lighter loads than with heavy loads.
53:55 In absolute terms, that is true. In relative terms, it's not. So, in relative terms, your heavy strength training exercises, especially if they're contracted position, are going to be mostly metabolic related fatigue, which is why you can just bang out set after set after set of them. Um if you leave a reasonable rest period, because they just bounce back. Metabolites leave the muscle and completely bounce back and don't leave any problems behind. This is a really important thing. So, um yeah, I think um if it's a multi-joint exercise like a hip thrust, then you'd have metabolic related fatigue. You'd have a little bit of super spinal from the cardiovascular sensations that you were getting, cuz you would be dumping lactate into the system, cuz the muscles you're using are big, and you would have that respiratory response to that um to that lactate entering the system from the muscles that you just used. So, I think you would have a sort of super spinal fatigue effect. Um but again, um you know, how long that would last uh I don't know I don't really know. Okay, so so you said that so calcium ion minimal.
54:53 It'd be fairly minimal in the contracted position with heavy loads, yeah. Yeah. And then the the super spinal, so if it's a multi-joint, it'll be higher. If it's a unilateral single joint, for example, then it'll be lower. >> sure. So, if you were doing like a um triceps extension, um you know, maybe banded, so you were trying to aim for the contracted position. Um you know, you probably wouldn't have very much super spinal fatigue at all in that particular context. So, let's let's stick with hip thrusters as the multi-joint example and like banded uh triceps extension as the as the single joint one. I think really, you'd see mostly metabolites in both, but you'd see a bit more super spinal in a hip thrust, simply because you've got that multi-joint uh exercise creating a cardiovascular response. So then if you gave a long rest period for both of those, you've let the metabolic fatigue dissipate, the spinal fatigue we're not concerned about, and the hip thrust is suffering from some super spinal, but in that long rest period we should have dissipated the super spinal CNS fatigue as well. So in a long rest period, basically all of those fatigue mechanisms should have dissipated mostly for the hip thrust, right? Of course the thrust is I mean they're both going Yeah, for both. It's just that you've kind of wasted some time with the triceps extension cuz you didn't need that hugely long rest period. Yeah, so now let's say short rest period. So let's what, maybe say 30 to 60 seconds as an example. Well, it depends. I mean like I think 30 seconds you're starting to have some spinal CNS fatigue still present. I think you probably you probably if you aim for a minute, if you if you say a minute, then I would say that the hip thrust is still going to have some super spinal, you're still going to have a cardiovascular response.
56:31 You're probably going to be losing a bit of recruitment on your second set. Triceps extension, probably not. Yeah. Yeah. So see that's really interesting cuz we're saying ultimately if you're doing 60 seconds, you're probably getting everything out of that in the triceps extension. There's no need to wait 2 3 4 minutes. No, I don't think so. Now if we were to compare that to moderate, let's say 12 repetitions. Same exercise, it's still going to hip thrust and you still have our triceps banded extension.
57:02 Well, now with the hip thrust you really are going to have to wait because you are going to have a meaningful cardiovascular response. So So we still got the metabolic, we still don't have a lot of calcium ion really, we still got um obviously now more super spinal in both scenarios, there's going to be more super spinal, but ultimately way more in our hip thrust example, yeah? You are you are going to have more of everything. Uh we're not As soon as you increase rep ranges, you're going to have more of everything. So you are going to have a little bit more calcium ion related, you're going to have more spinal, you're going to have more super you can to more metabolites. Um that mean that just goes with the territory.
57:36 But yeah, I mean in terms of the hip thrust, you are probably going to have to wait a good couple of minutes longer now. Um you know, and in terms of the triceps extension, um yeah, I mean again, probably going to have to be waiting a little bit longer, but not not anywhere near as much. So again, if we if we say this we this minute kind of timeline we we waiting a minute, you'd say with a triceps extension there's probably there may still be a bit of super spinal CNS fatigue present. Yeah, I think I would probably put because again, super spinal doesn't just come from a cardiovascular sensations, it will come from a metabolite feelings as well. So it's not from anything discomforting. So if you finish your triceps extensions and that you can feel the ache in your arms from the from the kind of the metabolites accumulating, and you can still kind of feel that like 30 45 60 seconds later, then you you just probably going to have to leave it another 30 seconds. So I'm I'm not saying what the number is, but you know, it's going to be probably a little bit more than >> Yes. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah.
58:40 Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. >> Um but again, you're moving both of them upwards, you know, with the hip thrust and and the and the triceps extension you started out, you know, kind of at different levels with the longer rest period being required for hip thrust. As you go to higher rep ranges, both of them just move up together. You know, it's not like they change relative to each other. They still stay the same more or less relative to each other.
59:01 It's just that both of them require longer rest periods now. So now the hip thrust, so previously we said maybe 3 minutes or so is probably going to be adequate. So now we're saying, "Hey, that might be 5 minutes." Yeah, it might be. It might be. 4 or 5 minutes depending on the person, depending on the load, muscle mass, all of that. Yeah. Which is why I started this episode by saying I think the standard 2 3 minute recommendation doesn't make any sense because if we're talking high repetition multi-set, it needs to be longer.
59:29 Uh sorry, high repetition multi-joint. And if we're talking low repetition single joint unilateral whatever, realistically it's it's going to be shorter. And this is a >> this is the this is the thing that I keep trying to avoid ranting about and I just keep coming back to, which is that on the one hand you've got evidence-based trying to tell people to you know, kind of do the same thing all the time with everything because that's the only way that they know how to think. And then on the physiological side, you've basically got people saying trying to say, "Well, what is the reason that you are trying to you know, kind of increase the rest period?" And if you understand the reason that you're trying to increase the rest period is to avoid primarily avoid super spinal fatigue. Um then suddenly you can now start to program different rest periods in different situations.
60:15 And yes, it is going to be very different. If you're doing a you know, multi-joint exercise like a squat and you're doing moderate loads and you you know, 10 repetitions per set, that is going to require much much much longer rest period than if you're doing biceps curls. I mean, that's just how it is. And then once again, we could say the same thing if we were now say someone had the desire to do a 20 25 rep set, then each of those times it is going to get pushed further up again. I mean, honestly when you start to get into 20 rep plus territory, your rest periods are almost academic because you aren't recovering.
60:56 The only time I can I mean, maybe there's an exception to this, but the only time I can ever recall programming a set that that high to say like I might do this with back extension where it's just impractical maybe to load it too high or something like that. And I would do it as one set, the final set of the workout. Because you're probably going to need 15 minutes before their their heart rate's going to be back down to normal. So, I'd be like, "Do this set, walk out of the gym. We're not You're not going to wait any longer. You're not going to wait through another set."
61:24 >> Absolutely. I mean, I think that's what you have to do. I mean, it doesn't make any sense otherwise. Um I mean, just kind of coming back to the examples that we started with the hip thrust and the triceps extension, which is banded to make it um hardest in the contracted position. You could now look at examples of say a back squat and a biceps curl and maybe a preacher curl. So, you've now got a stretch position exercise instead of contract position exercise. What you've got to appreciate now is that the reality is that none of the modifiable fatigue mechanisms are any different.
62:00 So, if you compare your hip thrust and your back squat, and okay, I know there's muscle mass differences in the back squat's going to feel a lot more cardiovascular than a hip thrust, but ignoring that, um you aren't really going to see any differences in terms of what you can modify. You aren't going to lose more reps on those two stretch position exercises, but you can't do anything about it. You literally can't do anything about it cuz once the calcium fatigue >> to 12, both of those exercises are going to suffer the same from the calcium fatigue. Is that what you're saying?
62:29 What I'm saying is that let's say for example, you were doing hip thrusts, and I said to you, um pretty much the only reason you're going to be losing reps is super spinal CNS fatigue. Um so, try and avoid uh losing reps, and you kind of you know, realize that you can keep your rep numbers across three sets by doing 4-minute rest periods. Fantastic. I can't do that with the squat because there's no way in which you can avoid losing reps unless you're immune to calcium and beta-T, which nobody is. I mean, I know that there's some nonsense flying around where people think that the repeated about effect is some kind of way of avoiding fatigue happening full stop, which is absolutely nonsense.
63:06 But, you know, there's there's like um you can't actually avoid losing reps in a stretch position exercise because the calcium and beta-T doesn't go away inside the workout. So, repetitions in reserve, talk to us about that. So, um what we've talked about so far then is mainly the rep range um and the stretch position being the two primary drivers of what your fatigue is going to look like after each set. Uh approximate failure, as I've already said, is going to affect uh I've already pointed out that it affects calcium myoelectric quite a lot, but it also affects metabolic rate of fatigue.
63:43 So, you're going to get hit by both of those. And then if you look at the super spinal spinal side of things, obviously you do get hit there as well. So, basically every fatigue mechanism that we've uh talked about so far, or groups of mechanisms, cuz these aren't specific mechanisms, they're groups of mechanisms, these groups of mechanisms of fatigue are going to be very negatively affected by those last couple of reps extra to failure. Now, I often refer to that in the context of post-workout fatigue because calcium myoelectric is very, very sensitive to those last couple of reps.
64:13 But the others are as well, just less so. So, what you'll find is that you will drop fewer reps if you leave a rep in reserve or two reps in reserve than if you uh train to failure. So, if you are looking to use shorter rest periods, then using reps in reserve is a very, very effective way. And if you take that to an extrapolation, then you realize that that makes clusters >> [laughter] >> a lot more logical if you want to use If you If you want to go down the rest period shortening rest period, maybe you've got like a desire to structure a workout plan that is highly efficient for time reasons, clusters is going to be a lot more efficient cuz it's just another step in the same direction.
64:52 You know, ultimately you try and stay uh further away from failure, but you're trying to get as many stimulating reps as possible as you can. Well, okay, then just use clusters with heavy loads then. Yeah. So, proximity to failure, reps in reserve, you've obviously said it affects all these clusters clusters of fatigue mechanisms. Shouldn't use the word clusters cuz you can do it again. Yeah. Um But those some of those obviously don't matter that much in the sense that they will still recover. Some of those won't recover like calcium and fatigue. So if someone had longer rest periods 5 minutes or whatever, it doesn't really matter if they're doing an exercise that isn't that susceptible to calcium and fatigue accumulation, damage, etc.
65:37 If they take that set to failure because they'll be able to recover from that in the 5, 6, 10 minutes, however long it is depending on how many repetitions they've done. But if someone is doing a stretch position exercise, they're not going to recover from that. So arguably that would make more sense. That's an interesting point. I mean I always argue that reps in reserve makes more sense when you're using strict position exercises because it's supposed to work out to be modified as well.
66:03 Um but yeah, it does make sense in the context of a single workout. So um yeah, I mean if you're again comparing the the hip thrust and the uh banded um triceps extension with the um the squat and the preacher curl, um then yeah, I mean we could train to failure on the contract position exercises and, you know, leave the rest period and then go after it again and that would be fine. In the case of the stretch position exercises, the squat and the biceps curl would be like, "Well, does it make sense to leave a rep in reserve here or there?" But you also want to be sensitive about the rep ranges. I mean, always going to be more sensitive about rep ranges in those calcium overload fatigue situations as well. Um I mean ultimately you can the way that you can see it is that um with contract position exercises, you can get away with a lot more. You can do higher rep ranges, you can do training close to failure, you can do high volumes, you can do the whole kind of thing. I mean, like you can chase those sort of more body golden era bodybuilding ideas if you really want to a little bit.
67:05 I mean within reason. I mean, not like we've seen today with the example work that he showed us, but like you can change those things a little bit if you want to do that. But, on the stretch position side, you just can't do that. It won't It won't re- It could catch up with you either within the workout and you'll lose reps like nobody's business, or it'll catch up with you in the post-workout and it will create a lot of post-workout muscle damage.
67:26 One application of what we've talked about here and what we've talked about in other episodes where we talked about clusters, we talked about drop sets, and we kind of made this point last week when we were contrasting clusters and drop sets to where you might use one versus the other is some of these variables matter a lot more or will influence different exercises in different ways. And when you look at programming what I see is most most of the time people will use a method or a structure, they'll use a repetition range, they'll use rest periods, they'll use whatever variables and they'll just blanket apply to every exercise in that program. And in reality, these variables ultimately should actually be specific to that exercise. And you know, we said this last week with clusters and with drop sets, if one were going to use uh use drop sets, it wouldn't make sense to do that with an exercise that was more susceptible to a lot of supraspinatus CNS fatigue.
68:19 That's where clusters would make more sense. So, I think I think the takeaway for me with that is is a program if a program looks really uniform all the variables are the same for every exercise, odds are you're actually shortchanging some of those exercises. In some cases, yeah. I mean, I think there are some variables that just work for everything. I mean I mean, leaving practical leaving practical considerations aside, if if you can practically use a heavyish load for every exercise that you've got in your program, then a heavyish load is going to work for you. I mean, it just is.
68:55 >> Yeah. Um similarly, if you want to leave one rep in reserve for every exercise, again, that's going to work for you. >> You're not going to lose anything by doing that. Yeah, sure. >> no. I mean but if you're going to failure for every single exercise and you do multi sets then that would be a case where actually some of these exercises >> yeah, now you got a problem. So I think I think there are some training variables that just do work for everything. So like if somebody wants to program in the 5 to 7 rep range and they want to leave a rep in reserve then most of the time as long as the exercise doesn't have a practical Yeah, so you got a super vanilla program which will work basically for everything. You got like a single set 5 to 7 one rep in reserve that's going to work basically for everything. But if you want to do something that's a little bit more exciting >> doing if you want to start well firstly let's recognize that there are going to be some exercises that people just don't either feel comfortable programming in that rep range or maybe there's practically difficult to do in that rep range. Okay, fine. We're not really talking about that.
69:51 Then if you want to then say well okay, but could I do a higher rep range you know anyway and I'm like well yeah if you've got a contract position exercise you could push it into a slightly higher rep range. It wouldn't really create you huge issues. Similarly training to failure again contract position exercise again it's not going to really create huge issues for you. It's It's going to start costing you on the on the stretch position exercises much much more if you start making those choices. And now the same thing then applies if you now start to my rest periods. So if you're doing a multi set protocol then you could you know just leave 4 or 5 minutes rest on everything and you're not cuz you're logically you're not really making a mistake there.
70:33 Practically you're going to be really bored but okay fine. It's It's not going to create huge problems. But you could start to chisel away at that rest period for your smaller muscle mass exercises where you're not creating a super spinal sensitivity. So you look at all your arm work or your single joint stuff and you could go okay I don't need to take those super for rest periods. I can actually get away with 9 seconds or you know, whatever.
70:59 Um and as I said before, if you really want to know, you can literally just start checking this yourself. You can either just literally count reps. Because if you're losing a lot of reps straight away, you know that it's not working. Or you can use a heart rate monitor and just monitor, you know, whether your heart rate is coming down or not. I mean, if it's still really, really high on your second set, then it's telling you that you're probably not ready to do a second set. Um you know, so I think there's there's ways and means of of kind of checking this, you know, ourselves if we want to do that.
71:29 Yeah, that's interesting. So, you could literally have, you know, call it a vanilla program before where you've got single sets, five to seven, you know, four-minute rest periods, one rep in reserve, and you could say, "Hey, you you can't you can't screw this up, really." Like maybe you could you could fail to Yeah, if you get bored. Or you might you might fail to choose appropriate exercises to train the muscle you want to train, but that format is unscrupable. And then if you want to go outside of those bounds, you want to use multi-sets, you want to use higher repetitions, you want to train to failure, whatever, then really you you kind of need to understand, at least fatigue, and you need to understand how those variables are affecting fatigue to still be able to have an optimal training program.
72:12 Yeah, although I would point out that, you know, this is not mysterious in the sense that it's happening outside of our perception. I mean, like, you know, most people can do a set of squats and realize that they are now cardiovascularly cooked for the next 5 minutes. Which is why most of these silly plans work when we consider fatigue, because they were able to intuit what was happening. Because you can feel it. Exactly, it's not mysterious. It's not it's not happening outside of your um kind of visible spectrum, if you want to call it that. I mean, it's like it's it's happening in your lived experience. So, like you do some bicep curls and within a minute or two, you should feel ready to do another set. You're not feeling any sensations that are telling you that if you do another set, you might drop a rep.
73:01 Whereas you may still you may still drop a rep though. You may still in the case of biceps, especially if they're in a stretched position because you've got calcium on the teeth but the point is that you probably shouldn't feel like you're going to drop another rep when you try again. Um you know, the contracted position exercises, that should actually more or less be the case. You shouldn't be really dropping reps. I mean, that's an interesting observation itself is that if you feel like you should be able to perform maximum performance and you don't, it's probably pointing towards calcium ion fatigue. Yeah, I mean some of my very fav I mean like how can someone have favorite fatigue studies? I have favorite fatigue studies.
73:37 Um but I I do have these favorite fatigue studies and there's a couple of them involving um drop landings. And basically the protocol is that you um I actually this is one of those studies where um I actually remember where I was when I read it the first time. That's how much I like this study. So >> [laughter] >> I remember I was sitting on a train and I was reading this study and wow, this is amazing.
74:04 Um basically I was sitting on this train what reading this study and um and there was a uh there was a family and the kids were making a lot of noise and I was trying to focus on this study and after a while I just forgot about the family making a lot of noise because I was so so engrossed in this amazing study. And um and yeah, it was this basically protocol where people would uh there would be like a sort of a set of steps up to a uh sort of a box if you like and the subjects would walk up the steps onto the top of this box. Not a high box, just it was to try and minimize the concentric involvement. And so you you walk slowly up the steps and then you would drop landing onto the ground then you walk back around and you walk up the steps and drop landing, walk around. And they did this many many many times. And the really interesting thing is that it's a very, very effective protocol for creating almost no fatigue mechanisms of any kind apart from calcium related fatigue.
74:57 Because you get this stretch activation. So, stretch and activation at the same time in the drop. And because you're moving relatively slowly and and and evenly all the other points in the in the in the protocol, you don't really build It's just like walking down the street. I mean, you don't build metabolic related fatigue or super spinal fatigue or spinal fatigue walking down the street. So, you're just walking and then very gradual set of steps and then drop and then again. And what happened was that the presence of fatigue as measured by dynamometry was quite meaningful. So, the level of fatigue was really, really kind of visible on the son of strength train measures that were done. But there was zero sensation.
75:37 Mhm. Absolutely zero sensation. And this is abs- This is crazy to me. Because basically what you're you're isolating is all of the other stuff that we normally get out and just going we're getting a pure sort of calcium related fatigue. And you can kind of do that with a stretch, although it's not quite so cut and dry, but you basically you're getting this kind of pure calcium related fatigue. And it was You can just imagine these people kind of noticing that they're getting weaker and weaker and weaker. They can't feel anything that's giving them signals of to why that's happening.
76:10 It's absolutely amazing to me, but yeah, really cool protocol just demonstrating you can isolate some of this stuff off in certain circumstances and and create pure types of Like you can with static contraction, but you know, this is another way of doing it. An exercise related way of doing it. Um so, yeah. I mean, basically anytime you've got that kind of stretch position exercise component, you are going to be losing repetitions and you're not really going to be able to feel that that You're not going to be able to predict that based on how you feel. It's not going to happen. Mhm.
76:38 Mhm. Yeah, so you've you've said a moment ago, you can you can feel your super spinal CNS fatigue coming into the next set. Well, you must be able to cuz it is literally a sensation that's driving that reduction in your ability to um produce motor recruitment. So, someone can do things like check the heart rate, Mhm. uh you know, be conscious of their breathing. Um I mean, they're going to be the main metrics that they can they can assess.
77:08 And you know, for me like I've mentioned in the past, I've been playing around with this quite a lot using a heart rate monitor. And you know, I'm finding with low rep sets, even multi-joints, multi-joint upper body lower repetition sets, I'm finding that often within about 30 seconds, my heart rate is basically back to baseline. And it's not until I've done multiple sets, four, five sets, that I'm there's that fatigue accumulation occurring in my case. Um and you know, I'm I'm noticing my breathing rate isn't coming back down to normal and and whatnot.
77:40 So, if I'm doing like a a classic protocol or even if I were to do a drop set protocol with low repetitions and you know, slightly longer between those drops, like I'm finding for me there's very little fatigue that's that's carrying over. Well, there's still going to be metabolic, but very little super spinal CNS fatigue that's carrying over. Yeah, I'm mostly the same except with the exception of um with pulling exercises. It really it doesn't really matter what rep range I'm working in. As soon as I stop pulling things, then then I'm just my heart rate spikes and I'm done.
78:11 But Actually, an interesting observation on that. So, in the Poliquin world that I came out of, a common narrative, a common common sort of statement was don't take pull-ups to failure sets of pull-ups. You do a set of pull-ups to failure, go you know, do five to failure, next set you'll get three repetitions or two reps or whatever, you'll drop heaps. And it was like pull-ups like this mystical exercise when it comes to like nothing else really is as bad as that. I don't know if that's an effect on that pull-down, but yeah, okay. Well, well, that was That's my question. Is and I know you're going to say this. I know cuz for you back is weird, yeah? But for me, I take a set of lat pull-down to failure, sure there's still a huge cardiac acid demand of that. But if I give it long enough, I will be able to perform that set well like to a similar standard again in a few minutes time. If I take a set of pull-ups to failure, I don't believe I'd be able to perform that to the same level again in a few minutes time.
79:13 And And maybe it is just I need longer. Maybe if I gave it 5 or 6 minutes instead of 3 or 4 minutes, maybe the pull-up would be the same as a lat pull-down. And I suspect it probably would be. I mean, there's no reason it wouldn't be. >> test it. Yeah, exactly. I will, yeah. But I suspect that's what it is. And so it's making me think actually that advice all along with should have been just take longer between pull-ups. Like that That probably would have been the solution.
79:38 I don't know. That's an interesting idea. I I honestly find um high rep pull-ups so offensive that I never do them, but Well, even just high load. I would notice the same thing if I was to load it for >> not the same. more than five rep five or six reps, you'll have the same experience. Okay. So, people can measure to an extent super spinal CNS fatigue. They can gauge calcium ion fatigue just due to performance drop when they feel like >> they're recovered between those sets.
80:06 You know, there's a point actually I wanted to say from the silver era. This I thought was a very astute observation from Steve Reeves. And for a while it didn't make sense to me. I've made this commentary before where like I'll see stuff in the silver era but like I don't know why they did that. That They got this bit wrong. And then like a year later I'd be like, "Oh, that's why they did it. It makes sense."
80:24 And I feel like that was Steve. So, in that workout we've covered where Steve was doing three different exercises per muscle group, one set of each. He suggested I I think he suggested 2 minutes rest between exercises. Okay, 2 minutes. Adequate, you know, he's he's most of these were most of them would have been more kind of single joint type exercises anyway. They're probably not a stack of fatigue, relatively low repetitions, low to moderate reps. And then he said, "Take 4 minutes between between muscles."
80:55 And I was like, "That doesn't No, you got that wrong. You should have waited longer between sets and and probably didn't need as long between pain muscles." And to your point before, well, if you wait longer between everything, you're not losing anything except efficiency. So, sure, he could have done that. That would have probably been better, sure. But, it That aside, I actually really like that idea of waiting longer between muscles because what you're doing is you're making sure there's no accumulated fatigue from your previous muscle affecting your next muscle. If there is some accumulating fatigue within that muscle, like you still got that first set on that first exercise that you mentioned before, you're still getting, you know, max activation in that first set. This is This is a better of of a potentially bad situation. I'd prefer that the muscle experience that fatigue than the a new muscle experience it.
81:45 No, I can see where you're going with that. No, yeah. Um I mean, again, uh a better approach is to look at the exercise itself and say, "Am I expecting a big chunk of cardiovascular sensation after this particular exercise?" So, If we classify the exercise based on what you think it's going to do, then that's where you want the rest period to be anchored, I think. Um but yeah, no, I mean, if you're looking for a a blanket recommendation, that's probably the lesser of two evils. Yeah. Well, it has made me think, you know, my recommendation to other people is I mean, really, I would cuz I'm often doing single sets, basically, I say is before your next set, but certainly before your next muscle, I want you to feel completely recovered. You know, even if I've said take 2 minutes off or 3 minutes off or whatever before you're doing that next muscle, I need you to feel fully recovered.
82:36 And, you know, we talked a few weeks ago on in one episode recently about the idea of even putting in smaller muscles between bigger exercises. Yeah, that strategy of exercise order of of sort of looking at your overall workout and going, "Well, you know, don't put all of your multi-joint exercises one after the other." And then all of your single joint stuff. I mean, I know that traditionally people have tended to go, "Oh, I want to do all the multi-joint stuff first and the single joint stuff later cuz I want to try and preserve equipment later in the workout." Okay, but reality is if you're trying to construct a a workout you want to get through, um you know, in an efficient way, then having a a kind of broken up between multi-joint, single joint, multi-joint, single joint, or whatever gives you a little because if you if you've done, say, I don't know, some hip thrusts or whatever, and then you go over and you okay, you give yourself a couple minutes, but you still can find sort of feel a little bit of kind of background sensation, you do some biceps curls, you're probably not really losing very much.
83:36 Um you know, whereas if you try to do another sort of multi-joint exercise like a pull or a press, you probably start to suffer um you know, some negative uh effects of of on the rep numbers. Um so, you know, I mean, again, we're not talking about um striving for perfection here. We're trying striving for something that's functional and and and and doable. >> Yeah. Um so, again, take it in that context. It's not supposed to be like, "This is the way to do it." So, I mean, again, you want to do it absolutely perfectly, then take all the rest in the world and, you know, kind of do it all perfectly right. I think like probably my favorite way to program, if I was to pick one, would be to pair a multi-joint with a single joint for that muscle. And we talked about this with Dorian Yates' plan, where there'd be a a multi-joint and then move into a single-joint, or even a unilateral. And for me, that just ticks so many boxes, cuz it is maintaining high recruitment in that same muscle, and or even increasing recruitment, and it's achieving what we've just said there, where you're just mixing up, and you're not, you know, putting all grouping all of your multi-joint really cardio vascular demanding exercises together.
84:41 I think if you do that, it's again, it's one of those formats where it's kind of hard to stuff this up. You get exercise variety, get high recruitment, and you you kind of mitigate some of this fatigue. Yeah. I mean, absolutely. Is there anything we haven't covered that we need to cover regarding rest periods? >> [laughter] >> Um well, I mean, there's there there are a few other things that are that are interesting about them, but nothing in the context of what we've been um talking about today. Um yeah, I mean, I thought I actually thought this would be a shorter conversation. I didn't think we'd go on as long as we have.
85:15 I think I think we actually could have kept going. There's there is actually a lot in this topic. Hopefully, other people feel the same way, but again, to the the point I've returned to a couple of times, we've outlined examples here where one could do 30 to 60 seconds between sets, or one could do two to three minutes, or one could do four, five, maybe even six minutes, and each of those would be appropriate. And so, this blanket statement of just do two to three minutes on take two, you know, two to three minutes between sets, it it just doesn't hold up. And it might work for half of the exercises you're doing, or or if you're doing very low rep sets, and it might work for all of them, but you don't need it for all of them. Like, it just doesn't make sense to do the same thing for every exercise.
85:57 Absolutely. I'm not going to rant again, so. >> [laughter] >> Okay. Okay, well, thank you guys for joining us. I do hope I my suspicion is that it will hopefully this conversation will change where people are programming. I know the more I've thought about this, it's changed the way I program. So, if it changes it for you, please let us know. Drop a comment, drop a question in our question box, a message, or whatever. I'd love to see your feedback.
86:22 Hopefully you join us for another episode, another conversation next week. Thanks, guys.
Summary
- The episode builds on previous discussions about drop sets and explores the confusion surrounding rest periods in training.
- Chris argues that general recommendations for rest periods are often inadequate and should be tailored to specific exercises and fatigue types.
- They analyze a high-volume workout routine from bodybuilder Serge Nubret, highlighting the extreme volume and short rest periods used.
- Fatigue mechanisms are categorized into central (CNS) and peripheral, with further distinctions affecting performance and recovery.
- The importance of understanding how different exercises (multi-joint vs. single-joint) influence fatigue and recovery is emphasized.
- The hosts advocate for a more nuanced approach to programming, suggesting that rest periods should vary based on the exercise type and individual response.
- They discuss the potential for using heart rate and perceived exertion as indicators of recovery between sets.
- The conversation concludes with a call for listeners to reconsider their programming strategies based on the insights shared.