Episode #358 :July 2025 Research Review (A New Twist On Supersets, CrossFit Injuries, and Too Much Cardio?)

0:05 [SPEAKER_01]: Welcome back to the Barbell Medicine podcast where we bring modern medicine to strength conditioning and strength conditioning to modern medicine. [SPEAKER_01]: I'm your host, Dr. Jordan Faganbaum, and this podcast is our July, two thousand twenty five research review, latest research brought to you by Barbell Medicine.

0:19 [SPEAKER_01]: We're going to talk about what rest periods are best for gains of four minutes, eight minutes, or how about super steady. [SPEAKER_01]: A new perspective study looks into CrossFit injury rate and risk factors. [SPEAKER_01]: And the last study we're going to look at is there's such thing is too much exercise.

0:34 [SPEAKER_01]: A new study finds out that masters and parents athletes have more cardiac scarring than their inactive peers. [SPEAKER_01]: What this means more all on this episode of the barbell medicine podcast on the other end of the line is the second most handsome Dr. North America. [SPEAKER_01]: And the guy with the best dad noises this side of the Mississippi doctor Austin Brock.

0:51 [SPEAKER_00]: Are we both on I guess we are both on the same side of the Mississippi at the moment. [SPEAKER_00]: So I'll take that as a as a high honor. [SPEAKER_01]: Well as a person who let who used to live very close to the Mississippi, but still on the same side. [SPEAKER_01]: I'm just saying that your dad noises are better than mine.

1:08 [SPEAKER_01]: If you say it's better than your dad's, which is weird. [SPEAKER_01]: I don't play bad. [SPEAKER_01]: But he's on the other side. [SPEAKER_01]: So fair enough. [SPEAKER_00]: Okay. [SPEAKER_00]: Yeah. [SPEAKER_00]: We're covering the U.S. [SPEAKER_00]: Yeah. [SPEAKER_00]: Things are going all right.

1:18 [SPEAKER_00]: Settling into the new place. [SPEAKER_00]: Training is actually picking back up again. [SPEAKER_00]: So as I suggested to you, I think my body just prefers San Antonio to El Paso. [SPEAKER_00]: That's the only explanation I can think of. [SPEAKER_00]: So here we are. [SPEAKER_01]: New study published in the Journal of Strength, Conditioning Research, Geographical Location of Games.

1:33 [SPEAKER_01]: You're right. [SPEAKER_01]: Yeah. [SPEAKER_01]: Well, you know, that makes sense because I had a bad training session. [SPEAKER_01]: So. [SPEAKER_00]: The switch is in order. [SPEAKER_01]: Yes. [SPEAKER_01]: Anyway, carry on. [SPEAKER_01]: Now, it'll be fun. [SPEAKER_01]: A few announcements before we get into the latest research one.

1:51 [SPEAKER_01]: Just want to plug our supercast. [SPEAKER_01]: Membership again, barbell medicine plus. [SPEAKER_01]: If you want to listen to these podcasts, add free. [SPEAKER_01]: You want early access to them. [SPEAKER_01]: You want transcripts. [SPEAKER_01]: You want discounts on our products. [SPEAKER_01]: You want early access to our products.

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2:15 [SPEAKER_01]: You can support what we do here and get access to all that stuff and more. [SPEAKER_01]: So go to Barbados in dot supercast dot com and sign up today. [SPEAKER_01]: And also we have a seminar on the books. [SPEAKER_01]: It's our only seminar for two thousand twenty five. [SPEAKER_01]: It's in San Antonio.

2:28 [SPEAKER_01]: It's in September. [SPEAKER_01]: We'd love to see you there. [SPEAKER_01]: We're going to do some additional sort of intermingling with the people who attend so we're probably going to train together on Friday and we'll likely try to get last time we were there we had a catered barbecue kind of thing.

2:43 [SPEAKER_01]: I don't know if we can if we can swing that again, but if so [SPEAKER_01]: I would prefer that. [SPEAKER_01]: Just to spend some more time, rub shoulders with the folks who come out and see us. [SPEAKER_01]: And yeah, it's a live in person seminar. [SPEAKER_01]: Dr. Barackie myself, Leo Lutz, Tom Capitelli, we'll have some coaching for the squad, the bench, the deadlift, and likely the press, and also some lectures and small group stuff should be, should be cool.

3:04 [SPEAKER_01]: So we'd like to see there. [SPEAKER_01]: That is linked in the show notes below. [SPEAKER_01]: Any other announcements? [SPEAKER_01]: I think we need to make. [SPEAKER_01]: Nothing else at the moment. [SPEAKER_01]: Those are the ones. [SPEAKER_01]: Yeah. [SPEAKER_01]: Well, the HSA stuff as well.

3:15 [SPEAKER_01]: So if you have been on the fence about Barbermanus and Coaching and you have a health savings account, we are now approved to use those. [SPEAKER_01]: So if you wanted to get some Barbermanus and Coaching, use your HSA stick it to big insurance companies. [SPEAKER_01]: We can do that, just set, I guess.

3:31 [SPEAKER_01]: Yeah, I guess. [SPEAKER_01]: Send us an email, support at barbolmedicine.com. [SPEAKER_01]: We get you set up. [SPEAKER_01]: Also, it's available on the website. [SPEAKER_01]: Be preferred to just do it on your own. [SPEAKER_01]: All right. [SPEAKER_01]: Well, let's get into the first paper.

3:40 [SPEAKER_01]: This paper is titled the effects of rest interval configuration between sets on volume load, during five sets of bench press and back squat exercise. [SPEAKER_01]: This is by Yamazaki and the research group out of Japan. [SPEAKER_01]: It's published in the Journal of Strength, the Kitchenary Research July, [SPEAKER_01]: to the study in the show notes as well.

3:59 [SPEAKER_01]: All right, so a little background here. [SPEAKER_01]: Conceptually, I find it useful to think about the amount of resistance training adaptations that somebody gets from exercise are related to the total training load. [SPEAKER_01]: Now, what is total training load? [SPEAKER_01]: Basically, it's the combination of the intensity.

4:18 [SPEAKER_01]: That's how much weight you're lifting or how hard the conditioning pieces and the volume. [SPEAKER_01]: So the total amount of reps and sets that you do for lifting weights or the total duration of the amount of time that you're doing conditioning. [SPEAKER_01]: So those are components of the total training load as well as the proximity to failure, the exercise selection, the rest period, etc.

4:35 [SPEAKER_01]: All of that wrapped in together, ripped together is the external training load. [SPEAKER_01]: The amount of adaptations that people generally get proportional to the total training load generally speaking. [SPEAKER_01]: Now, there's some nuance here where in the intensity, again, the how much weight you're lifting or how hard the conditioning pieces determines the type of adaptations that you get.

4:55 [SPEAKER_01]: and the volume, so again, that's how much of the training that you're doing. [SPEAKER_01]: Well, that determines the magnitude of the improvement. [SPEAKER_01]: So you need both pieces, but generally speaking, as a sort of central paradigm for how does exercise cause improvements in fitness and in health, well, the total training looks.

5:11 [SPEAKER_01]: So the total amount of training that you're doing, that correlates with the amount of adaptations that you're going to get. [SPEAKER_01]: More you can do the better for your performance and health generally speaking, provided that you can handle it. [SPEAKER_01]: Now, this leads to an optimization problem when it comes to rest period because if you just took that sort of general or central paradigm of, hey, do more, you get more, you would rest less because you would think that anyway because I would just do more work.

5:38 [SPEAKER_01]: Well, the problem is that if you shorten the rest period too much, your results likely suffer because people will have to take weight off the bar. [SPEAKER_01]: They'll have to go slower for conditioning. [SPEAKER_01]: They won't do as many reps. [SPEAKER_01]: So the total training load is compromised because you're doing [SPEAKER_01]: less weight, less reps, less volume, all sorts of stuff.

5:58 [SPEAKER_01]: Even though you're actually spending more time, quote unquote training, you just end up doing less total than you would. [SPEAKER_01]: So then you're like, oh, well, I just rest as long as possible. [SPEAKER_01]: So I can lift more weight and do more reps per set. [SPEAKER_01]: For example, well, the problem therein becomes how much time do you have to train?

6:14 [SPEAKER_01]: Because then your training session is just last forever. [SPEAKER_01]: We covered this a little bit in depth on our podcast on rest periods. [SPEAKER_01]: That's episode two, seventy five. [SPEAKER_01]: It's also linked in the show notes. [SPEAKER_01]: So this is where super sets get pretty interesting.

6:28 [SPEAKER_01]: Now, superset is when two different exercises are completed back to back, typically with minimal rest. [SPEAKER_01]: And there are three major flavors of these. [SPEAKER_01]: One is agonist agonist and that just means that an individual trains the same muscle group twice in a row with two exercises like doing bench press and then like chest flies.

6:44 [SPEAKER_01]: For example, now compared with splitting up these exercises and doing straight sets with rest periods in between each set, [SPEAKER_01]: The problem is the total amount of volume tends to be compromised because people do less reps per set. [SPEAKER_01]: They tend to lift less weight overall as well.

6:59 [SPEAKER_01]: And so between the limit in intensity and the limit in volume, people tend to get less hypertrophy results. [SPEAKER_01]: And less improvements in strength. [SPEAKER_01]: Now, you could set this up in a way where you could preserve the volume. [SPEAKER_01]: You'd just end up doing more sets.

7:13 [SPEAKER_01]: So you get the same number of total reps completed. [SPEAKER_01]: And then at that point, high-perch fear results tend to be the same. [SPEAKER_01]: But strength still seems to suffer because the amount of weight that has to be taken off the bar. [SPEAKER_01]: The second flavor of super sets is agonist antagonists.

7:26 [SPEAKER_01]: So these are opposing muscle groups are paired together. [SPEAKER_01]: So like bench press followed by rows or something like that. [SPEAKER_01]: It seems based on the existing research that total volume and the amount of force production per set, so how much weight the people can live tend to be maintained.

7:40 [SPEAKER_01]: And so you get similar results as compared to just doing them straight sets with rest in between. [SPEAKER_01]: And the third flavor of super sets are called alternate peripheral, where two completely unrelated exercises are paired together like a squat in an overhead press. [SPEAKER_01]: When you look at the data on this, and particularly with sets that are not taken to failure, so a couple reps left in the tank, the training volume, peak loads, and force production all seem to be maintained, so similar improvements in strength and high-perrophy when time is limited, awesome's favorite.

8:11 [SPEAKER_01]: Which is great, and I should say that it's your favorite because it's super easy for you to do, is particularly your home gym, right? [SPEAKER_01]: You can set up a deadlift and a press, you have to do racks, whatever, but if you're in a commercial gym, [SPEAKER_00]: Could be challenge.

8:24 [SPEAKER_00]: Yeah, depends on the equipment you have access to even at the gym that I'm training at now. [SPEAKER_00]: It's like very large and actually pretty well equipped and there's for example a platform right in front of a power rack and there's like a bunch of them. [SPEAKER_00]: And so I can even there sometimes take advantage of both.

8:39 [SPEAKER_00]: But yeah, for bigger exercises or kind of traditional compound movements, I like the alternate peripheral. [SPEAKER_00]: Sometimes for more isolation style stuff, I'll use agonist antagonists like for, you know, arm work or curls and tricep extensions or, you know, lat pull downs and things like that.

8:54 [SPEAKER_00]: I'll occasionally use that for that tier of exercise. [SPEAKER_00]: And then I pretty much never do agonist agonist. [SPEAKER_00]: That's not to say there's, I guess, never a role for it. [SPEAKER_00]: I don't personally use it in my own training or programming for others myself. [SPEAKER_00]: What about you?

9:06 [SPEAKER_01]: Yeah, that's pretty much the same. [SPEAKER_01]: Like the Agonist Agonist stuff, I kind of say for very short periods of time where I'm really trying to take a lot of sets to failure, mostly with the aim being for hypertrophy. [SPEAKER_01]: But in that case, I'll actually program a specific amount of reps such that volume is not compromised.

9:24 [SPEAKER_01]: I don't want, you know, for example, just five sets taken to failure. [SPEAKER_01]: I want X amount of reps over as many sets as it takes. [SPEAKER_01]: Most of them to failure because that's what this tends to induce. [SPEAKER_01]: And as long as I can preserve the volume, I feel better about that from a high-perch fee perspective.

9:36 [SPEAKER_01]: But I never really use it for strength because I don't think it will. [SPEAKER_01]: Okay. [SPEAKER_01]: So this study set out to compare the effect of three different rest intervals, so sort of programming setups. [SPEAKER_01]: They all did. [SPEAKER_01]: All the participants did five sets of five on both bench press and squat.

9:52 [SPEAKER_01]: The first group did basically four minutes of rest between each set of bench press and then four minutes of rest between each set of squat. [SPEAKER_01]: The second group did that with eight minutes of rest between each set. [SPEAKER_01]: So [SPEAKER_01]: that took a while, and then the third group alternated squats and deadlifts, or so our squats and bench press back to back, but with four minutes of rest between the set of bench press to squats, and then squats to the next set of bench press.

10:19 [SPEAKER_01]: So this is like alternate peripheral superset, although they weren't done back to back with minimal rest. [SPEAKER_01]: It's basically just pairing the exercises such that every time you do the set of bench press, you really had eight minutes of rest in between the last time you bench press, but only four minutes of rest between the set of squats.

10:36 [SPEAKER_01]: So they took thirteen young dudes. [SPEAKER_01]: They were moderately trained. [SPEAKER_01]: Their one rep max bench press was about two hundred pounds on average. [SPEAKER_01]: Their average one rep max back squat was two hundred seventy five pounds. [SPEAKER_01]: So these aren't like high level, you know, strength athletes, but moderately trained.

10:50 [SPEAKER_01]: I think is reasonable to say. [SPEAKER_01]: All of them did each of these three protocols over the span of five weeks. [SPEAKER_01]: And the intensity that they use for the bench press and for the squat was eighty five percent of their one rep max. [SPEAKER_01]: So pretty heavy. [SPEAKER_01]: That's like a five rep max.

11:04 [SPEAKER_00]: For example, although some of the sets they were getting like eight and nine reps with which Yeah, and it's based on like you said they're moderately trained they're not very highly trained and so I think that This it could be a criticism where you immediately are tempted to just like throw it all away, but I think that what you are [SPEAKER_00]: Essentially observing here is that as somebody goes from a very kind of novice beginner stage of training to becoming very highly trained quote unquote advanced even though you know those are nebulous terms, but your ability to coordinate and recruit.

11:39 [SPEAKER_00]: your neuromuscular skeletal system for a one-ret max effort gets better and better and better. [SPEAKER_00]: And so those percentages become more meaningful later on in your training progression. [SPEAKER_00]: Whereas earlier on in your training progression, there are so many other variables that can impact how well you can do that.

11:57 [SPEAKER_00]: like you have your paying attention to your technique and all the cues and all sorts of other things what's like you and I don't actually think about cues anymore we just like do the thing right and we can recruit a lot and very quickly very efficiently to execute a lift and so we have kind of I would say a little bit more predictable relationships between [SPEAKER_00]: relative percentage intensities like this and our, you know, retmax targets, whereas somebody who is not quite as far along that spectrum, there's a lot more kind of in the mix here that can make that a little bit more of a messy relationship.

12:27 [SPEAKER_01]: Yeah, typically when I see a smaller than predicted relationship between like eighty five percent and like a one rep max something like that. [SPEAKER_01]: Uh, that just tells me that a person is not very good at doing a single and usually a like a one rep effort, which basically comes down to training, how many times have they practiced doing a single rep effort, how efficient are they?

12:49 [SPEAKER_01]: And when I see a big gap, [SPEAKER_01]: like a greater than predicted when I'm like, oh, this person's either a stud at doing one or a max efforts or their work capacity is relatively compromised, whether it's a conditioning related thing or whether it's just not being exposed to that quite a bit.

13:03 [SPEAKER_01]: So yeah, definitely, definitely good point. [SPEAKER_01]: So as far as the results here, the main outcome was volume load. [SPEAKER_01]: And when I say that people like, let's, let's [SPEAKER_01]: training load, volume load, what the heck? [SPEAKER_01]: Basically, this is tonnage. [SPEAKER_01]: So the amount of weight that's lifted, but in the total amount of reps, in this case, over five sets of squats and five sets of bench press.

13:24 [SPEAKER_01]: Now, the weight was fixed in this study. [SPEAKER_01]: They all used eighty-five percent of their one-to-one max squat, and eighty-five percent of their one-to-one max bench press. [SPEAKER_01]: So really the differences that we're teasing out here are just volume. [SPEAKER_01]: How many reps do they complete for each set, total volume, for the five sets overall?

13:39 [SPEAKER_01]: So for the results here, the four minute, [SPEAKER_01]: rest period group again they were just doing four minute between each set of bench press then they switched to squats four minutes there it was about a forty minute training session the eight minute rest period between each set that was about an hour and twenty minutes and so the alternating group where they alternate back and forth between squats and bench press was also forty minutes so significant differences in the amount of time it took to do the sessions as far as total volume [SPEAKER_01]: For the bench press, the four minute group between sets, they did twenty one reps on average across the five sets total.

14:16 [SPEAKER_01]: And the eight minutes rest period group did twenty eight reps across the five reps for bench press. [SPEAKER_01]: And then the alternate group did twenty five reps. [SPEAKER_01]: The RPE was about the same, no significant differences in rate of perceived exertion. [SPEAKER_01]: For the squat, a similar relationship, the four minute group of rest period, they did the least, twenty three reps, the eight minute group.

14:34 [SPEAKER_01]: did the most, twenty-eight reps, total of squats, and then the alternating group did twenty-seven reps, so pretty close to that eight minute sort of comparator. [SPEAKER_01]: And again, the RPE was not really different between the three groups. [SPEAKER_01]: So my interpretation here, and then I'll get your take, Dr. Baraki.

14:49 [SPEAKER_01]: You know, the total number of repetitions, and subsequently the volume load for bench press and back squat, at eighty-five percent of their one-rout max. [SPEAKER_01]: For the eight-minute trial, we're greater than those of the four-minute trial. [SPEAKER_01]: And also a little bit higher than the alternating group.

15:04 [SPEAKER_01]: but not by much for the alternating group. [SPEAKER_01]: It was really, really close, you know, four reps left, less on the bench press, four reps left, less on the squat. [SPEAKER_01]: So, and basically, you know, less than half the time, forty minutes versus an hour and twenty. [SPEAKER_01]: So, to me, I'm like, [SPEAKER_01]: It's close enough because I'm unclear if four reps total or volume difference on a bench press and four reps less total month squat.

15:33 [SPEAKER_01]: So a reps total less in a training session. [SPEAKER_01]: I don't know that that matters. [SPEAKER_01]: Like, what is the minimal clinically important difference in volume to actually see a difference in hypertrophy in strength or whatever? [SPEAKER_01]: And so, I suspect that that difference is ultimately in consequential, particularly in the short-to-moder term, long-term, yeah, every session is eight reps less, maybe, but still, that's more speculation.

15:57 [SPEAKER_01]: Does that kind of job with your interpretation here? [SPEAKER_00]: Yeah, I think this is supportive of that bias that I mentioned towards a particular type of superset setup to save time and still deliver, you know, an analogous or similar degree of stimulus. [SPEAKER_00]: And, you know, when you say you don't know if it matters, I'm going to feel more confident that it does not matter.

16:14 [SPEAKER_00]: I mean, I think that if you were to sleep forty five minutes less on a random night, that probably has a bigger negative impact than one rep less on a particular set here or there in your training because to your point, [SPEAKER_00]: We would not expect this is going to be a pervasive systematic issue such that every session for months on and you're going to be doing significantly less volume as with anybody else.

16:36 [SPEAKER_00]: There's a lot of variations in human biology and performance. [SPEAKER_00]: Some days are going to be better. [SPEAKER_00]: Some are going to be worse and [SPEAKER_00]: Think when you're within this close of a range ultimately by the end, it ends up coming out in the wash and there's probably a lot of other things that you might be able to do with the additional time that you saved with that type of a setup compared with going, you know, to a significantly longer session just to complete your exercises in series rather than almost in parallel here.

16:58 [SPEAKER_01]: Yeah. [SPEAKER_01]: Yeah. [SPEAKER_01]: I also would wonder like if they took this out maybe for six weeks, they had them do this type of setup for three times a week for six weeks, what eight weeks, whatever. [SPEAKER_01]: Is there some sort of like work capacity adaptation wherein there's less of that sort of difference, you know, maybe then it's just one rep or two reps rather than four reps for each?

17:16 [SPEAKER_01]: I suspect that to be true just because humans adapt generally speaking to pretty much anything you ask of them as long as the dose is correct. [SPEAKER_01]: But yeah, more speculation because we just they didn't really do that here. [SPEAKER_00]: Yeah, I think that people get really hung up on this particularly earlier on in their training if they're very attached to their performance numbers on a given day.

17:34 [SPEAKER_00]: For example, they're really really wedded to [SPEAKER_00]: I have to hit this number for this many sets, then they might be tempted to stretch out their rest periods as long as, you know, possible to actually make that happen when that's probably not really necessary because you don't have to perform to a particular weight on a particular day.

17:50 [SPEAKER_00]: If you're training consistently over a long periods of time with a reasonably set up program, maybe it happens a little bit later, maybe other times you get surprised and you perform better and you end up hitting a milestone sooner than you expected. [SPEAKER_00]: And so that's kind of why we really like to take this decade plus long perspective on progress and training instead of session to session kind of details like this.

18:09 [SPEAKER_01]: I think the major takeaway there is that in training, we're not testing performance, even though it is a marker performance, but that the goal of training is not to test. [SPEAKER_01]: It's to build. [SPEAKER_01]: And so like, I don't need your maximum performance every single time it just needs to be good enough to drive an adaptation and there's a wide range that would work there.

18:27 [SPEAKER_01]: So overall, my take for rest periods and sort of how to organize this stuff, I think three to five minutes for strength work, like a really high priority, strength work, whatever your major main exercises are that you're really trying to push. [SPEAKER_01]: Three to five minutes is reasonable outside of testing.

18:41 [SPEAKER_01]: If you're testing a one-rate max and you're going to take eight minutes to ten minutes between single attempts, that's fine. [SPEAKER_01]: Yeah, and then two to three minutes for like size or high-perrophy focus training. [SPEAKER_01]: I wouldn't go below that a lot because again, you're compromising the total amount of reps that you can you can do and the total you'll end up getting closer to failure, which may not be what you want.

19:02 [SPEAKER_01]: Ultimately, we're trying to maximize the total amount of work done at the appropriate intensity and proximity to failure. [SPEAKER_01]: And if you shorten the rest periods too much, you tend to reduce the intensity, you tend to reduce the total amount of work done. [SPEAKER_01]: and increase the proximity failure so you're changing the variables there.

19:15 [SPEAKER_01]: And if you spread out the set too much by resting too long, you also compromise the total amount of work done unless you just have endless amounts of time to train. [SPEAKER_01]: Now, I'm going to bring up a little programming query related to total training load, total workload. [SPEAKER_01]: Number of sets versus number of total reps.

19:33 [SPEAKER_01]: So can think about these two things, Dr. Baraki. [SPEAKER_01]: You do a initial set of five repetitions at RPs, sevens with three reps left in reserve. [SPEAKER_01]: That's about eighty percent of your one right max for most folks. [SPEAKER_01]: And then you got to do twenty total reps.

19:47 [SPEAKER_01]: And each set is terminated at RPE seven. [SPEAKER_01]: So the workload there is fixed. [SPEAKER_01]: Compare that to five reps at RPE seven and then four sets to RPE seven. [SPEAKER_01]: So you would have a, you know, you might have more than twenty total reps. [SPEAKER_01]: You might have less and might be just twenty on the dot.

20:06 [SPEAKER_01]: I think that those are two different sort of programming approaches for different contexts. [SPEAKER_01]: The first one is a fixed workload. [SPEAKER_01]: You're doing twenty total reps period all sets to RPE seven. [SPEAKER_01]: That's it. [SPEAKER_01]: The second one is more dynamic on days that you're feeling it, quote unquote, you may do more than twenty total reps.

20:24 [SPEAKER_01]: On a days that you're not feeling it, it's going to be far less. [SPEAKER_01]: That's more dynamic. [SPEAKER_01]: And so I think the two applications for these are disparate, they're different. [SPEAKER_01]: Fixed workload, I prefer in a quote, resource rich environment, sleeping well, eating well, not a lot of life stress, whatever.

20:38 [SPEAKER_01]: And I really want to give you a big dose of volume because I think you can handle it. [SPEAKER_01]: Whereas the more dynamic one where it's like four sets to RP seven, cut it off. [SPEAKER_01]: I think that's more useful when there's a lot of life stress going on and or the intensity of the total, you know, sort of program is a little higher and people are more sensitive and needs a more dynamic type approach.

20:57 [SPEAKER_01]: How does that, how does that sit with you? [SPEAKER_00]: Yeah, there's a little bit more kind of built-in auto regulation in the second approach to where it'll automatically scale based on what you're capable of. [SPEAKER_00]: Whereas the former scales in a way, for example, in the worst case scenario where you're feeling horrible, you just do twenty sets of one.

21:16 [SPEAKER_00]: If every rep is that hard for the fixed workload, but I do think that that would be a still represent a pretty challenging stimulus for somebody who is in that in that state. [SPEAKER_00]: And so [SPEAKER_00]: uh... for somebody with kind of less predictable life circumstances recovery circumstances tolerance to training that the fixed workload is i i don't actually tend to use that style of uh... programming set up very often i think that because a lot of the folks that i work with do have a super variable situation whether they're you know work in health care there may be flip flip into days and nights and various other sorts of things uh... but if i do have somebody who is you know training towards a competition and they're there you know

21:56 [SPEAKER_00]: in a resource rich environment as you describe it. [SPEAKER_00]: I have certainly used the more fixed approach whether cut off by RPE or it kind of with other explicit programming parameters but to get this amount of work done kind of however you can. [SPEAKER_00]: So I think I'm we're aligned on that I think.

22:12 [SPEAKER_01]: Yeah, two different approaches, even though they're similar quite different as far as how it plays out. [SPEAKER_01]: All right. [SPEAKER_01]: Second study, this is titled, Understanding Sports Injury Risks in CrossFit, a prospective cohort study on athletic demographics, training profiles, injury history, and psychological factors.

22:28 [SPEAKER_01]: This is published in the Scandinavian Journal of Medicine and Science and Sports, July, two thousand twenty five edition by Naderi at Al, linked the paper in the show notes below. [SPEAKER_01]: All right, so let's give a little background here on CrossFit. [SPEAKER_01]: People have accused us of being like CrossFit sympathizers, you know, we're like pro CrossFit.

22:45 [SPEAKER_01]: And I don't know that either of us would identify that way. [SPEAKER_01]: Like, oh, we love CrossFit. [SPEAKER_01]: I think both of us are like CrossFit agnostic. [SPEAKER_01]: We're like, it's fine if you like it. [SPEAKER_00]: Yeah, I mean, I think I'm sure I think probably we both lean maybe a little bit more in favor than like absolutely neutral because I think if we were completely neutral then we'd be holding it up say in one hand and then, you know, saying that people who claim that gardening is their preferred form of physical activity and holding those up almost equally and I don't think that either of us would do that.

23:19 [SPEAKER_00]: There is some, you know, legitimate benefit towards exposure to some of the skills or the intensities or [SPEAKER_00]: The social aspect, the community various other sorts of things that I think even though neither of us currently choose to participate in that particular form, because we enjoy doing other things, I think it's more than more beneficial than neutral, you know, broadly speaking for people who do choose to participate in it.

23:43 [SPEAKER_01]: Yeah, I just think if you're comparing it to like a bodybuilding focus program powerlifting or general strengthening program, it's all about the same. [SPEAKER_01]: It's just preferences at that point. [SPEAKER_01]: But people, broadly speaking, especially those who interface with us and I don't know if it's just because our selection bias is like strength, you know, focused individuals and they have a little, maybe more knowledge or least perceived knowledge into training.

24:04 [SPEAKER_01]: They're like, well, it's, it's injurious. [SPEAKER_01]: The, the risk factor that for injury is super high with CrossFit and these workouts are dumb. [SPEAKER_01]: And I'm like, okay, made that point. [SPEAKER_01]: Yeah, maybe we are more sent with us or send that case. [SPEAKER_01]: And this is not unique to just people in this, you know, strength focused field.

24:20 [SPEAKER_01]: So, you know, fifteen years ago, Mike Boyle, one of these veteran coaches been around forever and ever. [SPEAKER_01]: said that, you know, high-repe Olympic weightlifting is dangerous, be careful with CrossFit. [SPEAKER_01]: Alan Cost Grove, another longtime coach, said that CrossFit's program is all over the place, and that there are more effective and safer choices.

24:36 [SPEAKER_01]: And there've other been positions taken against CrossFit from the ACSM and the NSA, and all of this is to say that a lot of people and national organizations with large platforms have been suggesting that CrossFit is dangerous for a long time. [SPEAKER_01]: But is this based in evidence or is it just vibes?

24:52 [SPEAKER_01]: You look at the actual data on this. [SPEAKER_01]: CrossFit's injury rate is very similar to what is seen in other type of resistance training. [SPEAKER_01]: It's about two to four injuries per thousand participation hours, nearly all published injury rates for CrossFit are in this window.

25:06 [SPEAKER_01]: So when people are like CrossFit is uniquely injurious, and I'm like, you got, you got receipts for that, or is it just bots? [SPEAKER_01]: And if it just bots, that's fine. [SPEAKER_01]: But when countered with this information, [SPEAKER_01]: do think that people should update their priors and be like, well, I feel that if it's done in a particular way, in a particular population, that it is more injurious, the risk is higher.

25:23 [SPEAKER_01]: I'm like, let's fine, as long as it has a contested and shown to be, how would you want to investigate that? [SPEAKER_01]: Because if there is a study that shows exactly how you would set it up, and it's different than would you update your position? [SPEAKER_00]: Yeah, that's the important question up front is like, you know, I think about this all the time in some of the discussions that we find ourselves getting into being curious.

25:44 [SPEAKER_00]: Sometimes I actually go through the exercise, asking the person sometimes I don't because it is apparent from the way they're speaking of, is there any type of evidence or what type of evidence would you need in order to change your mind on this? [SPEAKER_00]: I think that a lot of the times when we make a claim or stake a position on something, if we were asked that, we could, we could basically describe [SPEAKER_00]: what we would need to see in order for us to say, oh, guess I was wrong on that, right?

26:10 [SPEAKER_00]: When you're engaging with somebody on any topic, if you were to ask them that or consider actually asking them what type of evidence, you know, propose a hypothetical study that if it came out in a certain way, which would change your mind on this. [SPEAKER_00]: And then what do you know, maybe that study exists.

26:26 [SPEAKER_00]: Yeah, maybe. [SPEAKER_00]: Then the expectation is that, hey, maybe we ought to update things or caveat things. [SPEAKER_00]: It doesn't mean that we're attacking [SPEAKER_00]: your existence attacking you as a person, but rather it's like if this is our shared epistemology, our shared reality, then we ought to agree on what standards we're looking for.

26:43 [SPEAKER_00]: Whereas if there's no, there's nothing there, then you're unlikely to make much progress in the discussion. [SPEAKER_01]: Yeah, agreed. [SPEAKER_01]: The only two things that kind of stand out to me on the with the existing evidence base, which I talked about in podcast episode two, seventy four, the science of injury risk and crossfit.

27:00 [SPEAKER_01]: Two things that do stand out to me that that are potentially unique to crossfit. [SPEAKER_01]: One is the risk of rabdomylysis and I don't know if there's some sort of selection bias or like reporting bias when it comes to like, look, these people were performing this type of workout and they had rabdo.

27:14 [SPEAKER_01]: It does certainly seem like there have been more reported cases of rabdomylysis from crossfit than from like [SPEAKER_01]: power-lifting training, for example, or bodybuilding training, and whether that's due to the nature of the exercise or how it's completed, meaning like there's sort of competitive environment where the environments are hotter than usual or whatever, or just the highly motivated population.

27:34 [SPEAKER_01]: I think all of those things are reasonable to suggest. [SPEAKER_01]: So maybe a higher risk of wrapped in my license, I'd feel okay with speculating there. [SPEAKER_01]: And also individuals who are new to exercise, if they jump right into CrossFit, [SPEAKER_01]: I do think there is a sort of window of vulnerability there in that they're relatively untrained and they're kind of tossed into this relatively high workload competitive environment and there might be an increased risk right there, although again, that's mostly speculative.

28:01 [SPEAKER_01]: They're only like two prospective studies that have kind of shown that and it's not great data. [SPEAKER_01]: So I'm more like on the fence about that than I am the rabdo, but overall I'm like, and CrossFit probably has the same injury risk overall as other types of training. [SPEAKER_00]: like a reasonable position to you.

28:15 [SPEAKER_00]: Seems a very reasonable position based on the the data we have at this time in this very nebulous world of sports and training related injury. [SPEAKER_00]: There you go. [SPEAKER_00]: Yeah, right. [SPEAKER_01]: So what interesting tidbit that this studies adding to the sort of body of evidence is that there's this emerging role of maybe like psychological influence.

28:32 [SPEAKER_01]: on injury risk, so personality traits such as perfectionism, a strong athletic identity, poor self-control, an obsessive type of character trait. [SPEAKER_01]: These can lead to poor decision-making and training wherein people won't take weight off the bar or they'll add weight to the bar.

28:47 [SPEAKER_01]: For example, these are just two examples. [SPEAKER_01]: And so like perfectionism is defined as this character trait relating to the pursuit of flawlessness and excessively high performance standards. [SPEAKER_01]: Somebody has an athletic identity, identity, that's the degree to which they define themselves through their role as a quote unquote athlete.

29:03 [SPEAKER_01]: Self-control is the ability to manage thoughts, emotions, and behavior in the context of training recovery, particularly if it's going poorly, for example. [SPEAKER_01]: So this study aimed to look at the injury risk and crossfitters with a specific emphasis on these psychological factors.

29:18 [SPEAKER_01]: So the study. [SPEAKER_01]: It's three hundred and forty eight CrossFit athletes in Iran who had been doing CrossFit for at least one year three times a week and they had no injuries prior to enrollment in the study. [SPEAKER_01]: They did a number of assessments. [SPEAKER_01]: So they took this self-control inventory.

29:34 [SPEAKER_01]: The test is called a brief self-control scale. [SPEAKER_01]: It asks questions like, I focused daily on my long-term goals and people would rate, do they agree with this or not agree on a scale of one or five? [SPEAKER_01]: They assessed obsession and passion for exercise with the passion for exercise scale.

29:51 [SPEAKER_01]: Did not know that that existed before this. [SPEAKER_01]: They were asking questions like, I interpret threats as positive opportunities. [SPEAKER_01]: They assessed athletic identity, which was evaluated via the athletic identity measurement scale. [SPEAKER_01]: Great names. [SPEAKER_01]: Great names here.

30:06 [SPEAKER_01]: They assess perfectionism and more. [SPEAKER_01]: On top of that, so they did that at the beginning of the study. [SPEAKER_01]: And then participants were surveyed twice per week via WhatsApp, Instagram, DMs, et cetera, to check for injuries using a standardized questionnaire. [SPEAKER_01]: Now with this questionnaire and with the study design, [SPEAKER_01]: They defined sports injury as any musculoskeletal complaint experienced by an athlete resulting from training or competition, regardless of the need for medical treatment or time loss from training activities where time loss means they had to modify the training that they were doing or could not participate in an unrestricted way.

30:41 [SPEAKER_01]: All reported injuries were apparently verified via a physical therapist or with a specialist, either in person or over the phone, which I thought was interesting. [SPEAKER_01]: It wasn't clear to me that like a PT, you know, they got a hopped on a call or whatever, or saw the person in real life, and they were like, actually this is an injury.

30:59 [SPEAKER_01]: So I'd be curious to know, like if there was some sort of like we actually reported hundreds of injuries, but only seventy of them were real. [SPEAKER_00]: Yeah, the rest got reassurance that they were just sore in an expected fashion or something like that. [SPEAKER_00]: I mean, that's one scenario.

31:12 [SPEAKER_00]: I could potentially envision, but I don't know if these people have already been participating across it for at least a year, you'd expect them to have insight into that type of thing. [SPEAKER_00]: Totally. [SPEAKER_01]: So it was about a nine month follow up, uh, fifty three of the participants withdrew.

31:24 [SPEAKER_01]: So two hundred ninety five subjects remained. [SPEAKER_01]: The seventy-six individuals reported a total of ninety-four injuries. [SPEAKER_01]: So about twenty-five percent had an injury over the nine month follow-up period. [SPEAKER_01]: The rates were similar between men and women. [SPEAKER_01]: The actual injury rate was two point zero four injuries per thousand participation hours right in that two to four.

31:43 [SPEAKER_01]: You know injuries per thousand hours window that we talked about earlier. [SPEAKER_01]: The shoulder was the most common location for injuries in the second [SPEAKER_01]: Most common was low back about eighteen percent for each and people say well, yes, he cross with the injuries or highest in the shoulder and then the low back and knees were third and like yeah, these are the most common locations for humans to have injury periods so like not particularly surprising [SPEAKER_00]: Yeah, matching base rate that we see in lots of other areas and sports.

32:11 [SPEAKER_00]: There are some unique kind of, I would say sports with unique demands on particular areas of the body where you would expect a different pattern. [SPEAKER_00]: Certain injuries that you only see in certain sports really for example, but by and large when you when when you look at things very broadly speaking, yeah, shoulder back knees extremely extremely common.

32:27 [SPEAKER_01]: Yep. [SPEAKER_01]: Most of these injuries were mild. [SPEAKER_01]: That's important to note, requiring little to no time away from full unrestricted training, most from didn't require medical attention, most to not have severe pain, stuff like that. [SPEAKER_01]: So again, most self limiting, which kind of jobs with the existing data on this that [SPEAKER_01]: The injuries from resistance training, majority of them are not catastrophic.

32:45 [SPEAKER_01]: They resolve on their own within a week or two and don't require medical attention. [SPEAKER_01]: The risk factors that they identified now these were major risk factors so having like significant impact on the likelihood that somebody developed an injury. [SPEAKER_01]: Well, increase in the number of sessions.

33:01 [SPEAKER_01]: and increase in the duration of sessions, both of those things contribute to total workload training load that the person was exposed to. [SPEAKER_01]: Just exposure. [SPEAKER_01]: Yeah. [SPEAKER_01]: Yep. [SPEAKER_01]: Exactly. [SPEAKER_01]: A history of previous injury. [SPEAKER_01]: That would be an interesting question to ask your residents just off the dome.

33:15 [SPEAKER_01]: But hey, what's the biggest predictor for someone suffering an injury during exercise? [SPEAKER_01]: It'd be like, oh, it's got to be like orthopedic with something, but no, history of injury. [SPEAKER_01]: And they'd be like, oh, I should have thought about that. [SPEAKER_00]: Yeah, because it's such a common type of risk factor for lots of other conditions where the most common reason to have it is that you've had it before.

33:33 [SPEAKER_01]: Yeah, or family history of whatever. [SPEAKER_01]: Yeah, and then interestingly, from a psychological perspective, the sort of self-control had a big impact on risk, whereas the people with higher ratings of self-control had significantly reduced risk. [SPEAKER_01]: of injury. [SPEAKER_00]: This is kind of that self-control variable.

33:52 [SPEAKER_00]: I conceptualized that as like having Dr. Miles on your shoulder asking you the should you versus could you question before you go to take that set. [SPEAKER_01]: It's Dr. Miles on the good sides and should you do this? [SPEAKER_01]: And then I'm on the other side. [SPEAKER_01]: Send it.

34:06 [SPEAKER_01]: That's right. [SPEAKER_01]: Obsessive passion, those sort of character traits increased risk. [SPEAKER_01]: But yeah, things that might contrast to people's assumptions. [SPEAKER_01]: gender, age, BMI, coaching, or supervision. [SPEAKER_01]: None of these predicted injury risk. [SPEAKER_01]: So I'll take a lot of people when it comes to cross.

34:24 [SPEAKER_01]: They're like, oh, there's the coaching, the coaching is the problem. [SPEAKER_01]: And if someone's talking about maybe the programming and it's like suitability for a wide swath of the individuals, okay. [SPEAKER_01]: Like I'm fine with that insofar as it pertains to like workload, total workload, but the actual like supervision thing was kind of suggested against in this data set.

34:43 [SPEAKER_01]: Perfectionism and athletic identity did not have strong predictive power, which kind of violates the assumption, but also just an interesting thing. [SPEAKER_01]: That's why you have a hypothesis and you go test it. [SPEAKER_01]: I'd want to see this tested a number of other times before I completely wrote off those character traits because I do think there's probably something there, but not in this data set, and I'm fine.

34:59 [SPEAKER_01]: I'm willing to accept that. [SPEAKER_01]: So my interpretation here, [SPEAKER_01]: First and foremost, the injury risk and crossfit is similar to other types of exercise, whether it's powerlifting based training, bodybuilding based training, things of that nature, I don't think that crossfit.

35:14 [SPEAKER_01]: And I think it's reasonable to say that crossfit has a higher than normal injury risk compared to these other activities. [SPEAKER_01]: The second point is that most of the injury risk is secondary to increased exposure. [SPEAKER_01]: Whether that's the number of sessions, the duration of sessions, as the training load goes up, you get exposed to more and more and more.

35:32 [SPEAKER_01]: Yeah, that likely increases risk of injury, but that's not unique to CrossFit. [SPEAKER_01]: That's similar across the board. [SPEAKER_01]: It's just total training load. [SPEAKER_01]: And then opportunities, I guess, for more injuries, pass a certain point. [SPEAKER_01]: And again, to point out the third thing here that the history of injury, that is probably the biggest predictor here, the prior injury predicted a nearly four times increased risk of sustaining a new injury.

35:56 [SPEAKER_01]: And so, can't really do anything about that, not modifiable, you know, but at the same time, just something to have in the back of your head. [SPEAKER_01]: My only criticism here, you know, I like that it was prospective, so they like set the criteria and went forward with it, which I think is more useful because retrospective, you know, recall of injuries and other factors that there's some some squish there for sure.

36:19 [SPEAKER_01]: My biggest criticism and maybe my only real one here is that the injury definition is kind of stupid. [SPEAKER_01]: Oh, any muscular skeletal complaint? [SPEAKER_01]: And it did not compromise, necessarily compromise your training ability, didn't require a medical evaluation or whatever.

36:35 [SPEAKER_01]: That includes like Dom's, like the late onset muscle soreness, or what if you had like severe quad pain, ten out of ten quad pain, but it lasted for ten seconds. [SPEAKER_01]: Is that, that's an injury? [SPEAKER_00]: Like, yeah, it seems like the definition here is set up to be more sensitive than specific.

36:49 [SPEAKER_00]: I guess if we're going to use some biased statistical terms that they were aiming to just catch everything they possibly could and then maybe use this PT ortho consult to try to, you know, as a, as a screening kind of confirmatory test sequence to try to weed out the ones that were, you know, caught initially but, but, quote unquote fake or what, what we would deem is not true injuries.

37:10 [SPEAKER_00]: and hopefully to improve the specificity from there, which if that was in fact what happened where they did essentially a super broad swath of screening to catch everything they could and then kind of filter that through some degree of expertise, which we can say was that enough is that where they actually experts in this kind of definitional approach, that feels kind of reasonable to me compared with the opposite way around where [SPEAKER_00]: You only have injuries defined very originally in a particular way towards like anybody who's screen who matches this definition.

37:44 [SPEAKER_00]: It's like, yes, you can absolutely say they were injured, but it's like it's only if you had pain that kept you out of competition for six weeks or something like that. [SPEAKER_00]: It's like, well, there's there's some in between there. [SPEAKER_00]: I think that there is a debate to be had around this because it is a very nebulous topic.

37:59 [SPEAKER_00]: Unfortunately, you got to set your definitions somewhere. [SPEAKER_00]: I do like the concept whether this is exactly how they did it in the study or whether I just came up with it on the fly of almost like a screen and confirmatory approach would seem to give you some more confidence in the stats on the back end.

38:15 [SPEAKER_01]: Yeah. [SPEAKER_01]: If they did that, I retract my complaint and then I'm going to get them a pat on the back. [SPEAKER_01]: Yeah. [SPEAKER_01]: Right. [SPEAKER_01]: But if they did not do that, then it seems to me that if anything, [SPEAKER_01]: This injury rate, two point zero four injuries per thousand participation hours in this cohort, is artificially high.

38:31 [SPEAKER_01]: If they did not actually like, oh, this is not an injury. [SPEAKER_01]: We're taking this off the books. [SPEAKER_01]: So in that case, CrossFit's injury rate looks even better, and which much of the chagrin of people who want to hate on CrossFit. [SPEAKER_01]: So yeah, while higher training load tends to begin more gains, the people need to be able to tolerate it.

38:49 [SPEAKER_01]: If someone's new to CrossFit, they should probably cap the intensity and build, meaning that they shouldn't just go dark, max out on your effort here. [SPEAKER_01]: The results, the additional results that somebody may get from that sort of intensity are just really not worth the risk. [SPEAKER_01]: And so if I had any sort of [SPEAKER_01]: modification to how CrossFit is commonly practiced, although again, huge variation across the different gyms, different coaches, different programming.

39:12 [SPEAKER_01]: I would say, look, you're first, you know, six weeks across fit, none of the efforts that you do should be maximal. [SPEAKER_01]: And I just made up six weeks, and this is more speculative, because I would want to see that study to feel confident about it. [SPEAKER_01]: But overall, I think CrossFit is a fine way to meet or exceed the exercise guidelines, physical activity targets.

39:29 [SPEAKER_01]: I do not think that the data supports the idea that CrossFit is uniquely dangerous, not even close. [SPEAKER_01]: Yeah, there are risks and benefits to everything and even exercise, but the risks of exercise, including injury tend to be massively outweighed by the benefits, even if that exercise is CrossFit.

39:43 [SPEAKER_00]: Well said, I think that we've said it this way before, but you need to prepare for what you're trying to do. [SPEAKER_00]: You need to be prepared for the thing that you're about to attempt. [SPEAKER_00]: If it's something that's going on in the gym, the total amount of exposure that you have to it, that total kind of area under the curve.

40:02 [SPEAKER_00]: You can't avoid that there's some cumulative risk that goes along with that, but the cumulative benefits outweigh those cumulative risks in almost every scenario of exercise. [SPEAKER_00]: And even with all of those factors as optimally lined up as they can be, [SPEAKER_00]: Sometimes shit still happens.

40:20 [SPEAKER_00]: Yeah, and that's part of the game. [SPEAKER_00]: Right. [SPEAKER_00]: That's it. [SPEAKER_00]: To be like that. [SPEAKER_00]: There you go. [SPEAKER_00]: Yeah. [SPEAKER_01]: All right. [SPEAKER_01]: Right after this message from our sponsors, we'll be back with a third and final paper on the July, [SPEAKER_01]: Our way back here on the barbell medicine podcast is our third in final paper, the two thousand twenty five July research review.

40:40 [SPEAKER_01]: This is the interesting paper just came out in the journal circulation. [SPEAKER_01]: It's titled ventricle. [SPEAKER_01]: It's titled ventricular arrhythmia and cardiac fibrosis and endurance experienced athletes. [SPEAKER_01]: This was with the research group out of the UK. [SPEAKER_01]: Um, been getting a lot of air play on Twitter.

40:56 [SPEAKER_01]: Uh, for example, so let's give you guys a little background. [SPEAKER_01]: We're going to talk about the hearts. [SPEAKER_01]: and endurance training. [SPEAKER_01]: And specifically like risk of sudden cardiac arrest. [SPEAKER_01]: Now sudden cardiac arrest is defined as the abrupt cessation of cardiac activity to your heart beating so that the victim becomes unresponsive with no normal breathing and no signs of circulation.

41:17 [SPEAKER_01]: Now sudden cardiac death can result. [SPEAKER_01]: It's the abrupt and unexpected death occurring within an hour of the onset of sudden cardiac arrest. [SPEAKER_01]: Now post-mortem studies in athletes who have suffered sudden cardiac death indicate left ventricular fibrosis as one of the strongest predictors, mainly because it has thought that this left ventricular fibrosis can cause what's known as a ventricular arrhythmia.

41:40 [SPEAKER_01]: This is believed to be the main mechanism of sudden cardiac death in athletes, although the annual incidence of sudden cardiac death during sport varies between studies [SPEAKER_01]: It's reported to be up to six point eight per one hundred thousand athletes in certain cohorts and this varies by age sports and the level of training.

42:00 [SPEAKER_01]: So for example, it's much lower in middle-aged recreational athletes at one point two per one hundred thousand person years. [SPEAKER_01]: So it does change tends to be higher in triathletes who have a much higher workload and it tends to go up the older [SPEAKER_01]: that the individuals are, and it is predominantly in men, not in women.

42:19 [SPEAKER_01]: We talked about this on our podcast episode two hundred eight, which is also linked in the show notes. [SPEAKER_01]: So just to recapitulate, we're talking about the risk of endurance athletes, maybe having some fibrosis, so a little scar in their heart, that could lead to an arrhythmia, that could cause sudden cardiac arrest, which could lead to sudden cardiac death.

42:39 [SPEAKER_01]: That's really what we're talking about. [SPEAKER_01]: So let's talk about this myocardial fibrosis, this cardiac scar. [SPEAKER_01]: Myocardov fibrosis is characterized by a collagen infiltration into the muscular layer of the heart. [SPEAKER_01]: Typically due to lack of oxygen, such as during a heart attack, but also be from inflammation, so like myocarditis after an infection, or is the result of chronic exposure to high blood pressure.

43:02 [SPEAKER_01]: forcing the heart to pump against a higher pressure circuit. [SPEAKER_01]: There are other causes as well as different types of fibrosis, but that's the gist. [SPEAKER_01]: Basically, it's scar tissue laid down in the muscular layer of the heart due to some sort of injury. [SPEAKER_01]: Now, the presence and magnitude of myocardial fibrosis can be determined via microscopic analysis of cardiac muscle obtained by postmortembiopsy.

43:24 [SPEAKER_01]: If you take a little chunk of it, look at it in our microscope, or you can do a cardiac MRI and analyze this as well. [SPEAKER_01]: Now, it should be noted that the type of fibrosis, it has a specific signature. [SPEAKER_01]: So like after a heart attack, there's a specific pattern of fibrosis, as well as a specific region that is traditionally affected.

43:41 [SPEAKER_01]: And this is much different than what's seen in athletes. [SPEAKER_01]: And if you're a cardiologist, listen to this, you're well aware. [SPEAKER_01]: And I don't want to bore the audience by going into sub-end or cardio. [SPEAKER_01]: I don't want to talk about all that, but just you need to know [SPEAKER_01]: that based on cardiac MRI, we can see specific areas and specific types of fibrosis based on the cause of that fibrosis.

44:04 [SPEAKER_01]: Generally speaking though, in healthy individuals, without a history of heart disease, there's little to no sign of myocardial fibrosis on MRI. [SPEAKER_01]: However, the general population is not one hundred percent healthy, and in the largest study of non-athletes to date, the presence of myocardial fibrosis is somewhere between seven to twenty percent.

44:23 [SPEAKER_01]: A systematic review of endurance athletes, which in total included five hundred nine athletes, who had undergone cardiac MRI showed that the overall prevalence of myocardial fibrosis was five point nine percent. [SPEAKER_01]: Now, importantly, in that systematic review, we're [SPEAKER_01]: not just looking at older endurance athletes, not just elite level endurance athletes, not just endurance athletes who have been training you, ten, fifteen, twenty hours plus a week, but basically anyone who identifies as an endurance athlete, they got lumped into this study, and so the rate where they found some sort of myocardio fibrosis on MRI was five point nine percent.

44:56 [SPEAKER_01]: We talked about this on another podcast, excess exercise, talked about athletes' heart, this in some more detail, that's episode two, fifteen linked in the show notes below. [SPEAKER_01]: With all that background out of the way, this study aimed to determine whether myocardial fibrosis in asymptomatic veteran endurance athletes was prospectively associated with the incidence of ventricular arrhythmia.

45:18 [SPEAKER_01]: Before we get into the study design and the results, Austin, I would prefer if you could summarize this like, hey look, myocardial fibrosis, why is this important? [SPEAKER_01]: ventricular arrhythmia, why is that important? [SPEAKER_01]: Why are we even studying this in the first place?

45:30 [SPEAKER_00]: Yeah. [SPEAKER_00]: So having scar laid down in the heart muscle, as you mentioned, can happen for a lot of reasons in the same way that if you see a scar on a person on their face on their skin, it could have gotten there through a number of different [SPEAKER_00]: Mechanisms of injury it could happen from a cut it could happen from a fight it could happen from a burn it could you know all sorts of things that could happen to a person to lead them to develop a scar.

45:55 [SPEAKER_00]: It could happen from an autoimmune disease attacking their own body from all sorts of different things and similar concepts apply when it comes to scar being laid down in the heart muscle. [SPEAKER_00]: itself there are various mechanisms of injury by which it can get there and so if you in a kind of cross sectional fashion just take a group of people and you look at their hearts and you're very likely to find at least some people who have some evidence of scarring in their heart.

46:19 [SPEAKER_00]: You don't know exactly unless they have active issues. [SPEAKER_00]: You don't know when that happened in their life or necessarily what it came from. [SPEAKER_00]: But you can try to compare and contrast different populations, folks who are not terribly healthy with folks who are very healthy with folks who are maybe more strength athletes, power athletes, ultra endurance athletes, people who've been doing it for not very long versus very long periods of time.

46:40 [SPEAKER_00]: And you might be able to tease out different patterns or how often these people are found to have some of these things. [SPEAKER_00]: And so there has been this concern that [SPEAKER_00]: ultra, you know, endurance or very high intensity and very high duration efforts for very long periods of time decades at a time, for example.

46:59 [SPEAKER_00]: may increase the risk of developing some of this by what exact mechanism. [SPEAKER_00]: You know, I don't think that that's the purpose of this study. [SPEAKER_00]: Nor is it super well articulated at this point. [SPEAKER_00]: But if there is scar in the heart by whatever mechanism it got there, it can interfere with how electricity travels through it.

47:16 [SPEAKER_00]: Electricity benefits from having a nice clear electrical wiring system to go through. [SPEAKER_00]: And so when they're scar in the way, it can cause very erratic conduction of electricity and abnormal heart rhythms that can be potentially lethal. [SPEAKER_01]: Yeah, so effectively what you would want to find out is how many people in this endurance cohort have a scar?

47:34 [SPEAKER_01]: And of those individuals who have a scar, well, how many of them have some sort of arrhythmia? [SPEAKER_01]: Like if you're going to study them, study them for a long period of time. [SPEAKER_01]: So like not only do they have the scar, but is the scar maybe predictive of having one of these arrhythmias because [SPEAKER_01]: Zero out of ten would not want.

47:51 [SPEAKER_01]: So in this particular study, they took a hundred and six male cyclists or triathletes aged over fifty who had been doing greater than ten hours of exercise per week for more than fifteen years and had been regularly competing at local, national or international level competitions. [SPEAKER_01]: The average amount of training they were doing is like eleven to twelve hours per week for more than twenty years and they competed in somewhere between two hundred fifty to three hundred competitions over their lifespan.

48:17 [SPEAKER_01]: They had a comparator group of twenty-seven age-matched non-athletic controls who basically also did the same sort of tests and the same sort of follow-up period. [SPEAKER_01]: They had to be exercising less than three hours per week. [SPEAKER_01]: Now, all of the individuals in both the endurance athlete group and the non-athletic group, none of them were symptomatic.

48:38 [SPEAKER_01]: They couldn't have heart disease. [SPEAKER_01]: They couldn't have a history of aridmias. [SPEAKER_01]: They couldn't have a history of high blood pressure. [SPEAKER_01]: These are all exclusion criteria. [SPEAKER_01]: All of these folks underwent baseline physical exams and medical history, not only for what sort of medical conditions and medications do they take, but also lifestyle history.

48:55 [SPEAKER_01]: They all got a cardiac MRI and they all had an implantable loop recorder placed. [SPEAKER_01]: Now this is a minor surgery. [SPEAKER_01]: It's a small device placed just under the skin to record the heart's activity. [SPEAKER_01]: Just imagine your smart watch on steroids because it's really close to the heart.

49:08 [SPEAKER_01]: really fancy heart rate monitor. [SPEAKER_01]: Of note only six of them had them removed before the end of the study. [SPEAKER_01]: So interesting. [SPEAKER_01]: They also had an exercise stress test, which was monitoring for some sort of arrhythmia while they were exercising at maximum full tilt boogie.

49:23 [SPEAKER_01]: And they had about a two-year follow-up here. [SPEAKER_01]: So the results of the study. [SPEAKER_01]: of the one hundred and six athletes endurance athletes who had been training about eleven to twelve hours per week for over twenty years and competing a ton with fifty of them had some myocardial fibrosis on cardiac MRI and there were fifty six who had no evidence of myocardial fibrosis all of them who did have the fibrosis he did have this cardiac scar the specific signature was non-eschemic meaning it wasn't the same as a heart attack there was no evidence of heart attack or myocardial infarction in any of the athletes [SPEAKER_01]: The only difference between the group who of athletes who did have the scar and those who did it was that they were slightly older, about sixty-one years old, and those with the scar versus fifty-seven years old, in the ones who didn't have a scar.

50:12 [SPEAKER_01]: The athletes had a significantly greater prevalence of the scar, this myocardial fibrosis, than the healthy non-athletes. [SPEAKER_01]: So, fifty, again out of the hundred and six athletes that were studied compared to only three out of the twenty-seven controls. [SPEAKER_01]: There were no significant differences on MRI and any parameter between those with and without the fibrosis.

50:31 [SPEAKER_01]: So, whether you want to talk about like the different diameters, the different functionality, the cardiac MRI measures, so no real differences between those with and without the scar. [SPEAKER_01]: There were no evidence of issues with blood flow to the heart during exercise stress test in any athlete, regardless of whether or not they had fibrosis or not.

50:49 [SPEAKER_01]: But the real interesting thing here was that three out of the one hundred and six athletes who did have [SPEAKER_01]: A myocardio fibrosis had sustained ventricular tachycardia. [SPEAKER_01]: And an additional twenty had non-sustained ventricular tachycardia. [SPEAKER_01]: Austin, what is sustained ventricular tachycardia non-sustained ventricular tachycardia?

51:09 [SPEAKER_01]: What are you talking about here? [SPEAKER_00]: Yeah, to give a simple explanation, normally the electrical signaling through the heart starts at the top, called the atria, and goes down into the ventricles, and it gets conducted along kind of the expected highway of electrical conduction.

51:23 [SPEAKER_00]: Nice, smooth, fast, efficient, and it leads to the heart pumping kind of synchronously and efficiently. [SPEAKER_00]: When that electrical signal generates from a spot outside of that normal path, meaning it originates in the ventricles, [SPEAKER_00]: We call that usually a ventricular contraction.

51:42 [SPEAKER_00]: So sometimes your heart might be humming along, doing its normal thing, and then you get a little early heartbeat. [SPEAKER_00]: And when we look at it on an EKG, it looks a little bit funky and bizarre, because the electricity is coming from someplace else. [SPEAKER_00]: And so that's called a PVC or a premature ventricular contraction.

51:57 [SPEAKER_00]: When those ventricular contractions, meaning beats that were kind of triggered by electricity originating from a spot other than where it's supposed to come from and then it happens again and again and again, particularly quickly, we call that ventricular tech, the cardio. [SPEAKER_00]: That can happen for just a couple of beats and then it stops on its own.

52:13 [SPEAKER_00]: That's actually relatively more common. [SPEAKER_00]: I see that a lot of the time on my hospitalized patients because we're actively monitoring them. [SPEAKER_00]: And so we tend to catch more things when they happen, even if the patient has no symptoms, and they will say what they had a few beats of non-sustained ventricular tachycardia.

52:28 [SPEAKER_00]: So then we might ask a couple of questions about, you know, potential causes or contributors to that. [SPEAKER_00]: But ultimately it's not something that's an emergency in most of these folks outside of particular context. [SPEAKER_00]: Whereas if instead that ventricular tachycardia [SPEAKER_00]: sustains meaning goes on and on and on without stopping on its own.

52:46 [SPEAKER_00]: That's potentially dangerous and is not a rhythm that you can stay in long term compared with other rhythms like being in sinus rhythm or being even having a true favorite relation. [SPEAKER_00]: You can live with being that rhythm for a long time and not die. [SPEAKER_00]: But you can't be in VT for a very long time or indefinitely and be okay.

53:05 [SPEAKER_00]: So that's something we've tried to get you out of and address the underlying causes and contribute us for. [SPEAKER_00]: Because it's an example of one of these potentially lethal [SPEAKER_00]: Cardiac rhythms that we do not like to see, particularly when it is sustained. [SPEAKER_01]: Yeah, so to summarize, you don't want VT, whether it's sustained or non-sustained.

53:21 [SPEAKER_01]: Non-sustained's a little bit more benign, right? [SPEAKER_01]: You're like, okay, last some questions. [SPEAKER_01]: Rest sustained, you're like, you might need an implantable cardiac diffibrillator, for example, and actually one of the people who have this got an implantable cardiac diffibrillator.

53:32 [SPEAKER_01]: But of the one hundred and six athletes, twenty three total had some form of ventricular tachycardia, three of them were sustained, twenty of them were non-sustained, and more of those who had any type of this ventricular tachycardia had that scar that myocardial fibrosis, eighteen out of the twenty three versus only five, didn't have any of its fibrosis.

53:52 [SPEAKER_01]: So if you were just interpreting things to now based on what I've said, you're like, look, the scar thing. [SPEAKER_01]: It doesn't seem like I want that. [SPEAKER_01]: And if anything, it seems to increase the risk of ventricular tachycardia, or those with the scar for some other reason, may have a higher risk of ventricular tachycardia for some other reason that happens to co-occur perhaps with this scar.

54:14 [SPEAKER_01]: So my interpretation of all of this. [SPEAKER_01]: First thing I want to point out, all of these folks were asymptomatic. [SPEAKER_01]: Nobody had like chest pain, nobody had, you know, shortness of breath, nobody was like, wow, now that you identified this up, you know, I have been feeling a little funky.

54:26 [SPEAKER_01]: They were all feeling [SPEAKER_01]: You know, relatively normal. [SPEAKER_01]: The presence of that scar, non-eschemic, myocardial fibrosis, was significantly higher in athletes than a controlled group of age-matched non-athletes, four times greater, was the risk. [SPEAKER_01]: So, at the beginning of this, I said, we'll look.

54:45 [SPEAKER_01]: Some proportion of the population has a scar, typically not this non-ischemic pattern because there's either some underlying heart disease or something else. [SPEAKER_01]: We don't really know exactly, but it seemed to be that non-athletes tended to have a higher level of this. [SPEAKER_01]: Whereas this study, this particular group of athletes, it actually looks to be much higher than age matched control.

55:04 [SPEAKER_01]: So that's kind of interesting. [SPEAKER_01]: It suggests that there may be a higher prevalence of fibrosis and athletes [SPEAKER_01]: particularly older individuals, and particularly those doing a lot of training, eleven or twelve hours per week, for many, many years, and that's definitely a different sub-population of athletes that's been looked at before.

55:22 [SPEAKER_01]: And I think it's mostly due to age and how long these people have been doing the training for. [SPEAKER_01]: That seems like a reasonable conclusion. [SPEAKER_01]: However, I don't know that having that scar [SPEAKER_01]: is really driving the arrhythmia. [SPEAKER_01]: Theoretically, the fibrosis could be a marker of some sort of underlying cardiomyopathic process, something else, could have been happening that wasn't really assessed in this particular study.

55:44 [SPEAKER_01]: We don't know. [SPEAKER_01]: Another question is like, okay, well, look, if it is due to exercise, you just train less with that fixed-to-scar, because existing evidence today suggested that doesn't really modify the scar in some sort of salutatory way. [SPEAKER_01]: So, unclear there. [SPEAKER_01]: I guess despite the relatively high prevalence of this scar, this myocardial fibrosis, you know, and some of them having the ventricular rimia.

56:12 [SPEAKER_01]: Most of these endurance athletes aren't dropping dead during training. [SPEAKER_01]: And in fact, when you look at like major adverse cardiac events in endurance athletes, whether it's heart attack, stroke, or whatever, it's much lower than their age match controls in the general population.

56:25 [SPEAKER_01]: But that, that all being said. [SPEAKER_01]: We could focus on that, percent rate, and the podcast go off into the sunset, feel good about saying, tell them people like look man, don't worry about it. [SPEAKER_01]: There's still no condition that I know of, we're having a scar and the heart is good.

56:37 [SPEAKER_01]: Like, you would prefer not to have it. [SPEAKER_01]: I just don't know the significance of it based on this study alone. [SPEAKER_01]: One thought I had, I had did some digging it went down a rabbit hole. [SPEAKER_01]: What if there's like some sort of genetic interaction in this population where in some sort of genetic polymorphism or, you know, number of the polygenics sort of change?

56:59 [SPEAKER_01]: What if it like, [SPEAKER_01]: allows people to respond better to endurance training so they select that path, right? [SPEAKER_01]: But it also leads to a small subset of them having this, they develop a scar. [SPEAKER_01]: There is an example of this. [SPEAKER_01]: Most endurance athletes, for example, have this sort of preserved or really enhanced cardiac function.

57:18 [SPEAKER_01]: They, their heart pumps out more blood because they're trained a small subset. [SPEAKER_01]: actually has a reduced ejection fraction, seem out of blood that they pump out per heartbeat. [SPEAKER_01]: There's like a differential type of remodeling of the heart, even though they can sustain, you know, endurance activity at a high level.

57:36 [SPEAKER_01]: It's unclear if that's risky, but that is a subset of endurance athletes, and you're like, huh, is this some sort of genetic thing? [SPEAKER_01]: And that there seems to be some genetic traits that are genetic polymorphisms that are associated with that sort of adaptation. [SPEAKER_00]: Yeah, I wouldn't be surprised actually if that ends up being true to some extent.

57:52 [SPEAKER_00]: I mean, this is a similar cascade that we see in a lot of other health conditions. [SPEAKER_00]: So to give an example, like fatty liver disease is extremely prevalent worldwide. [SPEAKER_00]: Huge swaths of the population have it. [SPEAKER_00]: Only a small subset go on from having regular old fatty liver disease to having stiato hepatitis.

58:10 [SPEAKER_00]: only a small subset of those people end up going on to have cirrhosis. [SPEAKER_00]: Only a small subset of those people end up going on to have liver cancer. [SPEAKER_00]: Only a small subset of those people end up actually dying from their liver cancer. [SPEAKER_00]: And so, you know, we could apply that to lots of [SPEAKER_00]: other conditions as well.

58:28 [SPEAKER_00]: And so here you might have a large group of people who are being exposed to this thing of relatively high intensity and ultra long duration activity across the lifespan. [SPEAKER_00]: A not insignificant swath of them end up developing some of this cardiac fibrosis, like some of those percentages, were definitely higher than I think most would expect.

58:48 [SPEAKER_00]: But of those percentages, only a smaller fraction end up having maybe some sort of cardiac conduction abnormality, for example, electrical abnormalities on the EKG. [SPEAKER_00]: And then only a small subset of those actually end up having true arrhythmias be it sustained or non-sustained.

59:03 [SPEAKER_00]: And then only a small subset of those arrhythmias lead to sudden cardiac death, for example. [SPEAKER_00]: And so I think as far as an explanation of why or how there might be this big discrepancy between how prevalent the fibrosis is and how [SPEAKER_00]: You know, in uncommon, the actual sudden cardiac death is, that follows a similar pattern to a lot of things.

59:23 [SPEAKER_00]: What proportion of smokers end up building chronic lung disease, what proportion of those end up getting one cancer, what proportion of those end up dying of one cancer. [SPEAKER_00]: It gets smaller and smaller and smaller. [SPEAKER_00]: That's the way a lot of these things work. [SPEAKER_00]: And so I agree with you.

59:34 [SPEAKER_00]: There's not a condition. [SPEAKER_00]: I can think of. [SPEAKER_00]: We're scarring is good. [SPEAKER_00]: You'd prefer to not have it. [SPEAKER_00]: And I feel probably a little bit more. [SPEAKER_00]: I lean more in favor that the scar is likely contributory to the electrical issues that we're seeing here and probably plays at least a some part if not a large part of the higher risk of sudden cardiac death in that population compared to healthy age match controls.

59:59 [SPEAKER_00]: And so I think ultimately it's like, what do you do with this information? [SPEAKER_00]: Well, again, people who are training that much for that long, most of them are doing it for performance-oriented goals, competitive goals. [SPEAKER_00]: Most of them are not necessarily doing it to that level because they think that that is the best or the only way towards health and longevity.

1:00:21 [SPEAKER_00]: Some of them might be under that illusion that they might think that I need to do, you know, ultra marathons all the time to be maximally healthy and and have maximized longevity, which I don't think either of us would subscribe to that idea as that being necessary or even ideal. [SPEAKER_00]: And and so yeah, I think that if we're making general health oriented exercise recommendations.

1:00:42 [SPEAKER_00]: I think that this is a risk to be aware of. [SPEAKER_00]: I think it applies to a very small set of the population. [SPEAKER_00]: And so if I'm talking to somebody who's worried about this, I'm like, well, why do you train the way you do? [SPEAKER_00]: What are your goals? [SPEAKER_00]: It's like, well, I want to go and win, you know.

1:00:56 [SPEAKER_00]: the triple iron man this year or something it's like yeah well there's a lot of risk to do in that and this is you know potentially one of them there's maybe some things that we might be able to do to mitigate some of that risk as far as getting as good of control as we can other cardiovascular risk factor is trying to you know ensure your health is as good as it can be in all the other areas recognizing that.

1:01:14 [SPEAKER_00]: Hey, sudden cardiac death is fortunately uncommon, but maybe you're a little higher risk of that doing this than, you know, somebody who is doing general health and fitness exercise and not training towards this thing. [SPEAKER_00]: And a lot of those folks would say, yeah, I'm fine with that because I love this and this is what I want to do.

1:01:29 [SPEAKER_00]: You can't, you know, mitigate every risk in all circumstances, unfortunately. [SPEAKER_01]: No, and still be efficacious. [SPEAKER_00]: Yeah. [SPEAKER_01]: Yeah. [SPEAKER_01]: The authors, I listened to an interview with the authors and they said, [SPEAKER_01]: quote, there is no part of our message that is about doing less sport or even telling people to train less.

1:01:46 [SPEAKER_01]: Their whole point of this was like, well, look, this is a risk factor. [SPEAKER_01]: We don't know that the individuals who developed this, if they would like avoid it, if they might have avoided developing a scar, if they trained less, or if now they changed their training to train less, if the scar would resolve, or if they're risk of, you know, V-TAC would otherwise, you know, uh, uh, resolve.

1:02:08 [SPEAKER_01]: The real message that they wanted to get across was like, look, if you got a patient who, you know, isn't endurance athlete, and particularly an older, an individual with long training history or whatever, you're probably going to do an EKG on them for some sort of health screening, particularly if they have a report of like, look, I feel like maybe some premature contract or something feels funky.

1:02:26 [SPEAKER_01]: You're going to do an EKG. [SPEAKER_01]: If you find PVCs on their or whatever, it's probably not enough to just ask them a few questions and then just write it off, particularly in this population where they're training a lot, [SPEAKER_01]: the risk of having this mild card if I roast this maybe higher.

1:02:40 [SPEAKER_01]: And so at that point, you made it decide to get a cardiac MRI. [SPEAKER_01]: Just to say, well, look, do you got a scar? [SPEAKER_01]: Do you got the fibrosis or not? [SPEAKER_01]: And if they do, maybe you do a stress test to see, like can you induce some of this sustained ventricular arrhythmia?

1:02:54 [SPEAKER_01]: Because if so, that would be a significantly increased risk of sudden cardiac arrest and subsequently sudden cardiac death. [SPEAKER_01]: Still small, small risk, but non-zero. [SPEAKER_01]: And so I just don't know that I would tell somebody who's like, look, I want to live as long as possible.

1:03:09 [SPEAKER_01]: I want to be as healthy as possible. [SPEAKER_01]: I want to be as fit as possible. [SPEAKER_01]: Should I stop training at like five hours of conditioning per week instead of taking it up to ten? [SPEAKER_01]: I'm like, I don't think I can say that because I know that as you improve your view of two max and more activity like these gent things tend to promote help more than this risk.

1:03:26 [SPEAKER_01]: But if they ever said, yeah, I feel a little interesting thing in my chest, I'd be like, oh, well, cool, let's address that, because that seems reasonable to me. [SPEAKER_00]: Yeah, I think I'm on a similar train of thought. [SPEAKER_00]: You know, to the question of like, is any of this reversible, if they're to modify their training, I wouldn't expect it to be.

1:03:42 [SPEAKER_00]: I don't expect to see reversibility of like my cardiovascular scarring in these types of situations, but rather more so in like a perspective advisory way, if somebody's asking me for advice on training specifically for longevity, [SPEAKER_00]: My advice to them is not going to be, hey, instead of just like working towards meeting or exceeding the physical activity guidelines, instead, I think that you should be aiming to do like ultra marathon's multiple times a year.

1:04:06 [SPEAKER_00]: That's not the way that I would necessarily advise somebody towards a health and longevity oriented goal. [SPEAKER_00]: But even that advice is not just because it's like, oh, I'm just mortified that you're going to experience certain cardiac death by doing that. [SPEAKER_00]: It's just that the potential benefits of getting up to that level are not [SPEAKER_00]: necessarily worth it to most people.

1:04:24 [SPEAKER_00]: And there is some signal of risk here to where you could probably have a more favorable life if you didn't necessarily reach that far. [SPEAKER_00]: Totally. [SPEAKER_00]: Yep. [SPEAKER_00]: Yeah. [SPEAKER_00]: I think that's reasonable. [SPEAKER_01]: So I don't know that I would tell anybody to do less conditioning.

1:04:38 [SPEAKER_01]: But I do think that monitoring and assessing the people who maybe have something strange going on reasonable. [SPEAKER_00]: Yeah, me too. [SPEAKER_00]: Yeah, advising people to do, this is just applicable to such a tiny segment of the population who are actually training up to this level that I'm not terribly concerned with it.

1:04:54 [SPEAKER_01]: If you're training ten hours plus a week for just conditioning, I'm not talking you out of that. [SPEAKER_01]: Like, you know what I'm saying? [SPEAKER_01]: Look at what could I say? [SPEAKER_01]: They're like, well, you know, you got this risk and they're like, well, how big's the risk?

1:05:06 [SPEAKER_01]: I'm like, I don't know. [SPEAKER_01]: They're like, okay, cool. [SPEAKER_01]: I've got to get a new doctor. [SPEAKER_01]: Anyway, all right, well, that is a wrap here on our July, two thousand twenty five research review. [SPEAKER_01]: Thank you so much for listening. [SPEAKER_01]: Thanks to Dr. Austin Brocky for sharing his expertise with us.

1:05:21 [SPEAKER_01]: Before you guys go anywhere, please leave us a five star rating and a review. [SPEAKER_01]: It really helps drive traffic to our podcasts so we can keep bringing you a latest nuance and health and fitness from everyone here at Barbell Medicine. [SPEAKER_01]: I'm Dr. Jordan Viagambam. [SPEAKER_01]: We'll catch you next week and every week right here on the Barbell Medicine podcast.