 Hello everybody welcome to NASM Performance. We are now live for our latest edition of Beyond the Abstract with Dr. G and today we have a very special guest too which I can't wait to announce. Let's go ahead and see if we can get Guillermo on the line as well as our guests. Good morning. How's it going? Pretty good about you. Good. I gotta move myself here. I'm a little out of frame I think now so I'll see what I can do but yeah really excited for our episode today Beyond the Abstracts number 16 believe it or not. Can't believe it. And today's a really special one because we have a guest joining us. I don't think we've had a guest on since Dr. Shy Kvyetkovsky. Gosh sorry Shy. It's always a tug-of-a-ster with your name there. We went when we went over all things collagen so today's episode is really cool and I'm excited for our guest. Let's see if we can bring him in. There he is. What's up. Hello Nick. Dr. Nick how are you? Just Nick and you know you're looking extra slow right now. I did an extra set of bites of pearls this morning. Okay all right all right. I'm free Instagram live. And to this edition of Beyond the Abstracts this episode number 16. We have a very special guest joining us today Dr. Nick Rolnick aka Anik. So thank you so much for joining us. I always welcome the opportunity to discuss all things BFR strength and conditioning and muscle building I think those are all. Those basically encompass all my interests. Thank you for having me. I'm already on what we might be getting into today but for those of you tuning in Dr. Nick is leading us. He had a recent review paper public it was back earlier this year and I'm sure we'll get that. Tony you're cutting out a little bit for some reason we can't hear you very well. Can you hear me now? Now we can yeah. So let me let me start over then. So today we're pleased to have Dr. Nick Rolnick who is one of the world's leading experts in blood flow restriction training. He was also a contributor to our physique and body coach program. So we're really really thrilled that you're on Nick and can't wait to get into into the discussion today. One thing I'm sure we'll get into a little bit later is the recent paper you had published back in March which was looking at a review of the current research on on blood flow restriction training and I'm excited for you to share some insights and findings from that. So we'll go ahead and get into it. Tell us a little bit about yourself in terms of you know your backgrounds your DPT is that correct? Yeah so I am a physical therapist and a personal trainer. I actually say that I'm a personal trainer that's a physical therapist because for me exercise has always been a frontline intervention and more so recently given you know 70 percent of the population right now is overweight and or obese and there's nothing that can impact our own genes and optimize our function like exercise. So it really is an important part of what I do and how I believe we should be moving on a day-to-day basis and blood flow restriction is just a small albeit I guess significant in some aspects way that I can help keep people moving even when they're injured and giving them the benefits of heavy lifting. Awesome so some of us may be familiar with with BFR blood restriction. Can you briefly describe the history of it and how it originated, what populations it may be and then how that perhaps evolved and we've learned a little bit more of a wide variety of yeah so just Guillermo is he still cutting out on your end? Yeah yeah I'm not sure why yeah I think I think what he's asking is that look can you describe a little bit of the history of the BFR a little bit and then maybe just explain what BFR is because I know maybe some of our audiences and specifically know what BFR is specifically. Yeah well legend had it that Yoshio Kisato was older so in a Buddhist temple kneeling down and he started to feel this burn and this is in the mid 60s started to feel this burn in his calves like he was getting a pump and he then had the bright idea to say oh let me just start including my blood flow to the limb and do exercise with it and you know he or so has been told through you know his recollection or whatever his public you know story is that he started to experiment with restricting blood flow to you know his limbs and exercising and notice that he was able to in one of his injuries be able to recover faster and ultimately kind of created what is now known as katsu training or added pressure training in Japanese and that you know evolution took decades of a lot of practice and started to get into research but the effects or the the interest in ischemia or reduced oxygen concentrations in a limb has been something that exercise physiologists have looked at for you know in some way shape or form for like for like a hundred years but recently it's been applied I think the earliest paper that's specifically using vascular strength training which you know I guess is the time to kind of talk about bfr in and of itself where you're using some sort of device to apply it to the proximal most portion of your limb and in doing so it reduces blood flow that's flowing to the extremity and you're creating partial arterial restriction so blood flow is still able to get into the exercising limb but you're creating full venous occlusion so blood is unable to at least theoretically escape and that creates an environment to simplify it that basically stimulates high intensity strength training so you're able to with little loads and the loads that are really recommended are between 20 and 30 percent of your one repetition maximum whereas normal traditional strength training of moderate to high intensities of 60 plus percent of the one repetition maximum are commonly recommended to improve muscle mass and strength in practice so we're able to lower that threshold for people and that has a lot of relevancy for how we can approach strength training both in the injured populations that can't lift heavy due to either a contraindication due to from surgery or whatnot or if they have pain that is preventing them from lifting and that's a really cool opportunity for us as practitioners to be able to keep people moving but the earliest that I can that I found is a paper by Shinahara in 1998 to look at the effects of vascular strength training on strength but since then there have been hundreds of papers that have been published on blood flow restriction in a variety of different domains it started a lot in healthy people and then now it's expanded more and more into clinical type populations where where people are lowed compromise now nick I had a just a curious question on this history the the OG for for constant training uh was that he that he restrict the uh the the limb uh above the like you're supposed to in the proximal area or or they do it more distally on on the limb I don't know that's a that's a that's a good question I think I don't know um I actually don't know if he wrote that so he wrote a paper that was published in the international journal katsu trainer katsu some katsu based journal where you know in 2005 he kind of recollected the evolution of katsu training and I can't remember if he wrote that where he applied the actual um where he applied the actual band but convention is applying the band at the proximal most part of the limb because we have the most protection from a from neuro the neurovascular structures approximately and when we go distally so for example on the elbow we can create an ulnar nerve issue because the ulnar nerve is kind of right over here and so if we we restrict if we're doing forearm exercise we're we are at risk of damaging that nerve and if we're restricting at the cap we have the superficial fibular nerve that is right there wraps around the head of the fibula and that could create a foot drop um so you know or a common peroneal nerve that wraps around um my anatomy nerd would would peek out and say that's and then it branches off but anyway um yeah so the convention is is applying proximally because we it's all the same plump right if we restrict if we restrict proximally we're still going to get in effect of blood flow restriction uh whether we whether with at least you know safer um application parameters because now we're we're not um as close to the neurovascular awesome awesome and you touched a little bit on who can benefit from blood for restriction training but i just wanted to highlight what you said which is it's not just for clinical people it is not just for for healthy people it's really a broad spectrum of individuals that can actually benefit from local restriction training um uh and am i am i did i highlight that correctly yeah i think i think you know how i how i approach blood flow restriction is we have to understand at least to the best of our knowledge how normal strength training works if we understand how normal strength training works then we can fit bfr into that training paradigm and and so it makes a lot of sense that if we take the view that if we are lifting with heavy weights right which is traditionally the recommended approach that we're moving our our ability to shorten our muscle is already inhibited because the weight is too heavy so the only way that we can really get to that same level of muscle contraction speed which is really the driver when when effort is maximum to stimulate muscle growth that we need to induce fatigue and bfr just accelerates that fatigue process so i say that as a background because bfr is not doing anything super special when we talk about muscle growth we can apply it in healthy people we can apply it in injured people it just so happens that injured people by by far do not have the capacity to lift moderate to heavy weights and are and as such are relegated to sub optimal ways of stimulating muscle hypertrophy and the reason why we stimulate muscle hypertrophy and we need to stimulate muscle hypertrophy is because muscle is a is an endocrine organ right it's it's secretes these molecules called myokines or extra kinds and these are play a large role in regulating or stimulating adaptation but at the same time how regulate the systemic inflammation of our body so we have chronic lifestyle you know type conditions like obesity hypertension etc we want to minimize that that inflammation and having more muscle allows us to do that and when we're injured unfortunately muscle is one of the first things that goes we tend to if you're sedentary you're you're good on one day when we start to get to two three days a really not moving like if you're immobilized for example that definitely will exacerbate that we start to see losses in muscle tissue that can be visualized via imaging imaging like magnetic resonance and imaging like MRIs and so it's our our job is as clinicians for from the physical therapy side and even a personal training side because you're working with people that tend that are injured but are still coming to see you working with them understanding that muscle mass is a huge huge huge organ that we as fitness and those that are watching that are that are in healthcare providers that we have control of and so if we can understand how we can push our clients to the level of exertion required that will likely stimulate those adaptations that in and of itself is the best thing that we can do so you can apply bfr and healthy individuals you can provide an injured in fact i do think that while the adaptation profile of bfr and heavy lifting are likely identical on the molecular signaling level for the most part and we get the same adaptations i am very interested recently in the potential for bfr and aerobic exercise to actually get us beyond what would be experienced in normal high intensity work which is very unique and that's definitely an area that i'd like to see explored more in the body of research so that's a very long-winded answer for you but hopefully it provides some context to the people that are watching no awesome that's great now one question that i always have is if do you need the expensive equipment because i mean somebody far goes to can run pretty pricey and then of course you can you can go as cheap as like using e-wraps and then there's everything kind of in between you know us the bfr expert and by the way i took your course you know when you when you did it and it was a fantastic course i actually learned a lot about bfr training because it's something that i have utilized but i had never really implemented and you know a lot so it was it's a great course if those of you guys that want to get educated in that i would encourage that shameless plug thank you so much airman well that was it was it was actually just that you know really just that legitimate because i there's a lot of good information in there but one of the things i often ask is again what what equipment wise you know what what are the risks and benefits of using some of the cheaper stuff for the more expensive stuff so that's a loaded question only because so my position in the industry and why i'm i feel and what people have told me that i'm a trusted resource is i don't have any investment in any particular cuff company i'm purely about spreading the science of blood flow restriction and understanding and improving upon our understanding our knowledge of blood flow restriction so with that being said i think that there is i think that there is when you're working with people as a physical therapist or a medical provider i think there is a very important um uh responsibility that we should be using devices that are for more precision and the way that we do that in practice and unfortunately this is in the self-dependence box which we can talk about if we wanted to go into that but the the idea is that we want to make sure that we are applying a self-inclusive pressure to the individual that we're working with meaning that like if you like the easiest thing when i explain this to my my clients of patients it's hey um have you ever gotten your blood pressure taken i'm sure you have because you're here so definitely it's off on your life you've gotten your blood pressure taken well what we're going to do is we're going to pump this this device up basically like getting your blood pressure taken and we're going to work at a pressure that's less than that and typically the pressures tend to be between 50 and 80 percent of the pressure needed to completely restrict your blood flow and what we do know is is that by far and large we probably only need a moderate level of pressure by moderate i mean 50 to 60 percent we don't necessarily need high amounts of pressure and high amounts of pressure induce more discomfort and thus might reduce the compliance overall from the long-term training program so i say that because when we're working with people that are when we're working with people that are medically compromised we want to make sure that we're offering a more precise stimulus so any device that we that you can use to create a more precise application of blood flow restriction is likely ideal now there are very expensive devices and for me as being somebody that people supply me with devices or i'm able to get them at less you know cost i use more expensive devices typically in my own practice because they're they have the bells and whistles and i'm able to be more precise but that doesn't necessarily mean that they're inherently safer i think that as long as we're able to stick to recommended guidelines that we can optimize safe practice of vfr regardless of whatever equipment that we're using but typically when people ask me i tend to say hey you might need to buy a little bit more expensive cups and they vary depending on your you know your budget your patient population and whether or not you you know really feel your comfortability with the science of vfr so i think that when you're working with in the clinic or if you're a physical therapist athletic trainer we're just working with people that that are under your care from a clinical perspective i think you need to be a little bit more precise to minimize your liability but on the flip side when you're working in the fitness um when you're working in the fitness uh industry and you're working with people that are generally healthy i think we can be a little bit less precise uh what we currently know about the research is that we do need a minimum amount of pressure likely to accelerate the fatigue process it's going to give us the benefits over low intensity exercise so i do think that there is you know always the the the notion that yeah we should have these devices and they're getting a little bit less expensive but do i think that you need a very very very expensive device probably not um but i don't recommend practical vfr in the sense that we do have research that says that we can over or underestimate the amount of pressure that we're putting on our limb and for us you know for me that can either be working with less effective pressure meaning we're not giving enough pressure or we're applying a high amount of pressure that might even be super occlusive which would increase the likelihood of an adverse event even though full disclosure i think vfr is extremely safe uh in fact you know when i was at um the nsca conference in july i presented that it basically if you are safe to exercise you are safe to perform vfr um and and so that's the caveat we're saying hey listen what is your risk tolerance um even though we know practical vfr works i as a practitioner would probably want to have a device where i have some idea of the amount of pressure that's being applied to the limb and with that being said one of the projects that i was involved in was estimating if we didn't have something that could that could automatically calculate that pressure right what could we use as a surrogate that would likely put us within the range to apply vfr safely and so we looked at cups between nine and 13 centimeters which is typical width like four inches or so of cups that you would purchase you know a manual cup that you can pump up or even a worst-case scenario blood pressure cup um but that you basically can pump it up to this value and and basically be within an acceptable range of sub occlusive pressure and so what we found was that in our analysis that if you take 1.3 times your brachial systolic blood pressure that tends to be a good estimation of 100 percent of your limb occlusion pressure if you're using a cost between nine and 14 centimeters brachial systolic blood pressure so just your blood pressure value alone tends to be a good estimate for around 80 percent which would be the upper limit of what i would recommend for use in the lower body for example um upper body tends to be around 50 percent and then we found that no lie just using 100 millimeters of mercury so just pumping it up to 100 is about a good estimate for 60 percent of the limb occlusion pressure which really means that for the and for me as a somebody who um understands the how painful because it's not uncomfortable it's not comfortable 80 percent is and knowing that we can exercise at a little bit lower pressures to be able to get the same effect i usually exercise my client's sensations at around 60 percent anyways so it's actually a really nice way that you can say hey listen 100 millimeters of mercury if you don't have something like a Doppler where if you buy a cup you can probably get a good manual cup set for around $200 um but but you need a Doppler and a Doppler takes some skill and it's very difficult to practice so coming up with strategies to make BFR more accessible that are also evidence based is really really really important for me as i'm trying to kind of give bumpers to the growth of BFR as it permeates into fitness settings such as um nascent certified trainers awesome that kind of leads into the next question uh because the the article that you published was basically looking at the beneath the cup the overlooked and under-recorded Doppler restriction device features and their impact on practice so with regards to that uh you know one one question that i have is when you're looking at the BFR research and reading the literature because there's a lot of it especially in the last few years what are some important research design characteristics and features associated with the BFR application that can impact the responses that you see uh and the safety profile with our exercise yeah um so that paper for those that are interested that is like if normal BFR talk is here it's beneath it's in the weeds um of BFR and that's only because i have a very good familiarity with all the different features that different cuffs can have and and try to question whether or not the features that these cuffs have are more marketing or are they truly based in science and so when i read BFR papers i think of a couple things number one did they apply it according to guidelines and guidelines are typically between 20 and 30 percent of the one repetition maximum and there's two commonly recommended repetition profiles that are used which are four sets of one first set of 30 reps followed by three sets of 15 or sets the value and they're going to give us a couple of different avenues to explore in terms of interpretation of what they do but real quick but so i look mick with regards to that what's the rest period between those sets uh because uh typically it's 30 to 60 seconds is that correct yeah simply 30 to 60 seconds and they're pretty painful um because you're just if you can imagine the the last couple of reps of a of a moderate uh lifting set where you're accumulating some metabolites you know you're within that 10 to 12 rep range and you're feeling that burn well that burn gets trapped inside of the muscle so you're just sitting there just doing in that burn and that's really um where it can get pretty uncomfortable um but you know for me it's really do they do they follow guidelines right so lower intensity exercise with um or lower load exercise with resistance exercise between 20 and 30 percent of the one rep max and lower intensity aerobic exercise typically between uh less than 50 percent of the vo2 um vo2 max so it's pretty pretty low intensity and how is it applied right are they using an individualized pressure because what we know is if i apply the same pressure on you know you know on you as i do with me we might be at a relatively different percentage of lop um i'm knowing that i just said this basically saying that 100 millimeters mercury is good so it's kind of critical but that is the the the common notion of all right well we know that based that limb occlusion pressure is going to vary based on three things it's going to be very based largely on how big the limb is what your blood pressure is and how wide the cost that you're using is so if we typically are standardizing the cuff width when we're doing a bfr intervention and really the only two other variables are going to be the cuff width of the limb circumference and the blood pressure um so typically like individualizing the pressure accommodates all of those different factors so that's the most precise way to do it um but there are obviously less precise ways i just mentioned that before with the 100 millimeters of mercury um and then how is it applied is it applied throughout the the whole exercise or is it deflated during the exercise which is which which is a possible application of bfr it's called resting bfr when the when the individual exercise is then you pump up the cuff at the end and you trap those metabolites that have been produced but you're not doing it during exercise or or is it only inflated during the exercise and deflated during the rest that would be called intermittent bfr but looking at how that protocol is then designed is important and then obviously i'm a very big advocate that bfr is just like normal strength training except we're accelerating that fatigue from the cumulative uh accumulating at lower loads so i want the bfr to be done in a prescription that mimics what would normally be done with unrestricted exercise so two to three times per week is my bare minimum for the bfr efficacy if they do once a week not really um not really something that i would take any stock in given that it's not frequent enough and then the last bit would be following right are they hitting real quick nick i had one question with regards to that that was very interesting um with regards to that that two or three days per week you're talking about the research design but if i'm implementing it let's say as part of an overall strength and conditioning program i could do bfr save one day a week and then maybe do more traditional strength training another another three days per week right so you're talking about yeah yeah i'm talking about research so it's a normal like normal bfr application if you're using bfr once a week and you're you're predominantly lifting moderate to heavy weights you're going to have a similar repeated doubt effect for that's going to preserve kind of allow you to continue the positive adaptation because there's it's protection right and so if you're just doing bfr once a week that's fine um especially when you're doing it in conjunction with moderate heavy lifting but typically the research design is looking at exclusively bfr compared to some other intervention right um but but yeah there's definitely and there's definitely other areas of bfr that have been looked at like there's this there's this thought that because bfr is so low intensity that you can perform it very frequently and so that was interesting to me because it's commonly recommended so me and my colleague in brazil we did a scoping review looking at the whole body of literature on what we call high frequency bfr where you can apply bfr one to two times per day for you know anywhere from five to 12 sessions a week and and the thought in there is you're able to stimulate and create those adaptations on a much quicker time scale than what would normally be expected and what we found was bfr tends to work right statistically but when you actually critique the the bfr methodology like we just talked about and you critique the sensible analyses that were used it's very low level evidence and so what we basically said was it works clearly but we need a lot more evidence to really support that because that would also be a unique effect of of bfr is if we can stimulate adaptations quicker than moderate heavy lifting that would be interesting but what we actually found was and i came up with 27 different limitations uh and questions in the high frequency bfr literature so we're quite a while away from from kind of definitively stating that that kind of thing works but yeah these are all types of ways in which bfr has been applied and that's not even including studies now that are looking at pairing that with high intensity exercise like resistance exercise which doesn't really make sense to me and the research really is is more favoring my bias than oh it adds or high intensity interval training or high intensity aerobic training and looking at the ability of of bfr to increase vo2 max and potentially increase lactate threshold so that those individuals can work at a higher intensity and a higher relative intensity which has huge potential performance enhancement beyond just traditional high intensity exercise and that's the area i mentioned before i'm really looking forward to for future research but nick in in what in your introduction to this paper that you uh that you wrote uh you actually highlighted one study that actually looked at traditional bfr using that 20 to 30 uh load and then there was another group that did uh the traditional strength training but they use a traditional loading with the bfr and then they compared it to the traditional training alone without without the bfr and what was interesting is obviously uh strength gains was was actually higher in the the group that did the traditional strength training protocol with the bfr uh and compared to even the the one that was just a traditional strength training so i thought that was a pretty interesting study that you you guys discussed briefly in your introduction yeah i mean i think where you know for me i i just try to have a you know be aware of the overall body of of evidence and try to have a model where we fit into wherever these papers kind of come into play i know i think you're what you're talking about was one of the studies that looked at collegiate high school football players and what they did was they added bfr to a high intensity after so they did high intensity exercise and then they did bfr as a supplement and so basically what they were seeing in that study is we got a ton of questions by the way on the in the chat um but what they saw was an improvement in strength and in the group that did the supplemental bfr now my question when I look at that kind of research is is is that a unique effective bfr or is that because they just in general were able to get more volume and thus more muscle contraction in a specific pattern which typically they tend to test you know they test they basically you know and dr lenike um at all miss um he kind of is a really spearheading this it's like you can't train for the test like you're doing back squats and you're doing back squats at 30% but you're doing back squats at 80% of course the 80% is going to give you superior benefit uh in terms of strength because strength is specific right you're you adopt a more hip dominant pattern when you're lifting heavy than when you do when you're lifting light and so it's like you know these are all things to to consider with the application but yeah um the paper the beneath the cost paper is was kind of like my my my second my third like paper that I really wanted to get out there because it's not really discussed as much not much where we're talking about restricting blood flow but there there's a paper discusses different features that blood flow restriction devices can have and hypothesizes about their relevancy and we kind of take in different studies that have been used to investigate these um these features or talk about the potential for them to improve compliance by decreasing discomfort and so it kind of gets really in the weeds but I think the the two most relevant features that we discuss in that article is the presence of auto regulation of applied pressure and the different bladder types so typically um typically for uh auto regulation there is a device that is paired that's computer operated that basically creates a pressure around the limb that's relatively or what we think is relatively consistent so when we squeeze our like if we're doing a bicep curl then the cuff will dump out air to allow for the the pressure underneath the cuff to be maintained and then as we go into the eccentric the cuff pressure will increase so we're getting a relatively uniform pressure around the limb in a circumferential nature um and so that's been marketed time and time again as being something that's safer to be able to use and and I have always questioned that because we were being told by device manufacturers that this is safer but then there's really only been one study that's been done that you that kind of investigated the presence of auto regulation and its and its potential impact on how hard the exercise was how uncomfortable it was what was the blood pressure response and things like that so that kind of spurred my interest in exploring this in in a clinical trial basis and then we talked about two of the trials that I was involved in that had contrasting results which again kind of gets into the weeds because just because the cuff can regulate the pressure doesn't necessarily mean that all cuffs regulate the pressure the same the responsiveness of that auto regulation is going to dictate the performance and acute and the perceptual so how uncomfortable it is how hard you're working um so that was kind of discussing that I mean I have many more studies that are coming out that help design that are going to look and dissect this area a little bit more closely and then we have another section call that we've discussed with with multi chamber bladder systems so anybody watching these multi chamber bladder systems are not tourniquets when we apply bfr we are in essence applying a tourniquet to an exercising limb and and that has a purpose the purpose is reducing arterial inflow and including venous return these cuffs the multi chamber bladder cuffs are designed to not occlude blood flow at all because these little pockets of air are pressed down and it's while it's around the limb it's not circumferential and there's areas where the skin can expand into the divots between the different bladders so we're never able to reliably restrict blood flow yet the companies that produce these devices are marketing claims that they're just as effective as tourniquet based or single chamber bladder system costs and that really annoys me because when we looked at the totality of evidence there's only been a select handful of papers that have actually implemented this multi chamber bladder system and none of them help us understand whether or not it's actually the multi chamber bladder system that's causing the benefit or the fact that they just exercise to volitional fatigue in one in one side we know that bfr acts exactly like low intensity training except it accelerates the fatigue from accumulating so i designed another study that's coming out it's in review that should help um you know it challenges my biases i would say that right now um but it should be coming out in the next month or so um and that's really kind of what i'm about it's just i want to separate from what's marketing from what's the science and i will follow whatever the science says because ultimately i've seen bfr change lives i've seen it change physiques i've seen you know it really push push your understanding of xx physiology forward but those are really the two areas that we discussed that that are largely i would say relevant to um you know two practitioners looking to implement awesome i think tony we have a lot of questions i think we've we've had a good amount of uh responses here so you want to maybe look at some of those and see what we where we go now it's a little choppy still weird yeah i'm sorry everyone anything anybody for now has i like it super if you get a little closer it actually does help but we only get to see your nose but that's okay um we did have a quick earlier actually and nick you did address it you know the difference between auto regulated versus auto regulated versus not all regulated and which one do you prefer personally um listen i think that if we have the if you have the budget to purchase an auto regulated device i don't think that it hurts right like to give you an example uh and not to go too far down the rabbit hole but the two studies that we published um so far showed relatively a little bit contrasting results and one study used the smart cuffs generation three auto regulation which their auto regulation isn't as tight so the cuff wasn't able to yeah when you contract there's a large deficit so blood flow is able to kind of come in at least that's what we theorize and what we showed in that one was you can do more work with an auto regulated cuff than without that with that same cuff right but now not auto regulated and so it's like okay well that's one thing and it was less uncomfortable than the auto than the non auto regulated so it's like all right well let me let's go and let's try the $5,000 device right and and see how if those those similar trends persist and what we found was with a more responsive device that really tightly regulates the pressure applied to the limb we found no difference in in exercise the fatigue in terms of repetitions performed and in terms of perceptual so how uncomfortable it was and how um and how hard the exercise was we found no difference so so that to me says that there is something either with the exercise that we chose which was wall squat and the one that we did in the with the smart cuffs was a leg extension so maybe it has a bipartisan exercise I doubt it though my personal experience with both is that you know the this kind of parceled out to exactly how I was thinking it was going to parcel out to but do I but what we did find now actually which really blew my mind was that we measured arterial stiffness in the aorta so a lot of times we we think that oh we measuring our blood pressure at our arm or our legs right typically it's your arm and that's going to be reflective of everything that's happening inside and that's not necessarily the case when we look at central stiffness so the stiffness after exercise right it tends to it tends to increase in exercise particularly with resistance exercise and there tends to be no effect or less effect when we use aerobic exercise but nonetheless both of them have a have a way to adapt or create adaptation to our central arterial apparatus which ultimately makes us a little bit healthier right in the grand scheme of things um what we found was that auto-regulated application wanted the what we call the pulse wave velocity so it's a measure of arterial stiffness relative to non auto non auto-regulated and low intensity strength training which kind of doesn't make sense to me um but that's what we found um suggesting that there might be a small protective effect of using a tightly regulated uh device for central arterial stiffness oh but that being said we have no idea because we won't what what the acute increase in central stiffness actually means from a safety perspective we know that about one meter per second is an increase in that in the measure that we were looking at is associated with all-course morbidity and mortality but we found that there was no increase in central stiffness acutely in the auto-regulated condition but there was a 0.6 meter per second increase in the non auto-regulated and the low intensity exercise condition so in the grand scheme of things I just say if you are applying bfr to recommended guidelines you should be all good in terms of safe application and if you're not well then you're risking you know you're risking some uh adverse events happening that could probably have been preventable I love Nick you're you're a wealth of knowledge in bfr man I love it I love your passion you can just hear how much uh you know knowledge you have in it and and really uh I really appreciate all the work that you're doing in this field because it really uh is an area that needs to be explored I know I um I I didn't really use vfr a lot until uh after uh actually after I took her course I started implementing it periodically which was pretty cool um and uh I I've really enjoyed I think to me one of the challenging things is uh or at least initially was getting through my head that 20 to 30 percent of your 1 RM load is enough for for a stimulus and uh you know it's one of those things where you know I remember I was doing a leg press and I'm like what am I doing with I don't know 250 300 pounds on the leg press it's not it's light um but when you put that cup on there it is absolutely brutal um especially you know that first set of 30 like you feel it but then you get that second third or fourth in it I mean and that feeling is uh not at all pleasurable no and that's and that really to me is is like okay we know vfr works right in a variety of applications so whether or not you want to do practical vfr you want to wrap your arm with power lifting straps because that's really what I was doing when I first started it like a body builder I saw on the gym this is back in like 2000 and 2012 ish 2013 and I was prepping for a show and I was like I was kind of getting beat up because I was still of the high volume mentality and I was like oh what is that that's weird and then the bodybuilder was like oh it's occlusion training and like you're able to get a massive pump and you know build your muscles and so I was like all right sign me up uh and so I tried it and it was you know it was one of the things in the setup was difficult with practical vfr like it was just it was one of the things I tried for a couple weeks I was like yeah I'm just going to go back until the technology kind of caught up and then I started to it started to become a lot more feasible to do it particularly in the upper body lower body's never that problem never a problem but it's more like for me biceps forearms were how I was really applying it but yeah I mean it's all I'm all about minimizing discomfort associated with with vfr because it's we already know if you push yourself it's going to be uncomfortable but my interest is how can we mitigate that amount of discomfort so we are at the baseline or what we would expect the minimum amount of discomfort to be given this application of of vfr so any way that we can mitigate that while creating a similar benefit to exercise is something I'm very highly interested in now nick I think I want to we've been here a long time usually a little longer than norway we've had a lot a lot of fun but I wanted to get one thing is I thought somebody wants to order the amazon cost I don't think that we're necessarily advocating those for yeah and they're not that good I've tried them um you know I pride myself on understanding what's out in the market you're you're by purchasing a $20 booty band or what they call them like you're really not going to get the the effect of true bfr you'll get some minor effect I'd imagine but really it's important to apply a minimum level of pressure so it's really you're going to have to invest a couple hundred bucks to do so but these talks are particularly the ones that are a couple hundred bucks the majority of them not all of them but the majority of them particularly the ones you have to pop up yourself are pretty resilient to to use and as I mentioned before you don't necessarily need additional technology you can order the cost and you can just pump it up to a hundred millimeters mercury and know that you're likely going to be applying an amount of pressure that is going to be enough to give you those benefits but certainly the amazon booty bands I've seen on instagram people wearing them for a really long period of time if you if anybody's done bfr you're going to understand that you want those puff off as soon as you possibly you know you possibly can it's very uncomfortable um but that's again a marker of how you know you're doing what you need to do in order to stimulate muscle growth but I don't necessarily advocate for those amazon straps I think that um that they're they're cheap for a reason and particularly just think about this you are manipulating your blood flow okay why would you want to go cheap on that um it just it's one of those things where you just got to step and you have to think hey um I'm doing something that's really going to be you know impacting my physiology at least in a short term and yeah it's largely very safe to use in a variety of different people but what I want to really risk my you know potential health you know health effects for using something 20 bucks on amazon um you know those are the questions that I tend to tend to ask back to those people that are that are asking me for for those I'd much rather spend a couple hundred bucks knowing that I'm getting a good product that is at least going to be a little bit wider and it's going to be able to apply pressure that's going to actually restrict because if you apply 100 millimeters of mercury with a very small cup you will not get the same level of restriction as you're applying a cup that's three and a half to five inches long which is what we kind of booked at for our analysis and nick one last thing is uh you know I I don't want people to get the takeaway that we should be should only do vfr I think it's it's kind of important to understand that it has a time and a place and we can integrate it um and you don't have to be exclusive it's another tool in the toolbox that's very effective uh because I know even yourself I just I feed you I feed you uh put up good numbers on your bench presses you know a lot well over 300 pounds on that and you're not using vfr though but I see you also use vfr another uh methodology so can you just briefly touch on that yeah I think once we understand and this is where so this is I guess relevant to my online course because I really want to take a principle based approach to understanding vfr because we understand vfr through a principle based approach we're going to then understand how we can best apply it in practice so if we take the notion that vfr works through traditional means in the sense that what's happening at the muscle fiber level is largely identical whether you're lifting heavy weights or you're lifting lightweight with fatigue mind you lightweight without fatigue it's a little bit different but lightweight with fatigue where we're not moving the weight very quickly then we can pretty much slide bfr in whenever we want to create a high intensity stimulus for for ourselves and I am much the advocate that you know heavy lifting is always going to be the most efficient and it's going to confer the greatest physiological benefits to multiple different tissue types why would you then if you can lift heavy a vast vast vast majority of time spend more time lifting low load bfr unless you want to just be that person in the gym that people are going to look at and ask questions for like my whole thing is it's efficient and relatively more tolerable how do I know that because we actually did a meta analysis looking at that because that's another important area that I'm interested in is hot heavy load strength training when we're doing it to fatigue right when we're exercising eight reps we're going eight reps you know heavy eight reps it's actually going to be more tolerable than doing low load exercise to failure right so when we get to that point it's like you always have to ask yourself why bfr and going through the setup of that now if you have aches and pains like for example for me I'm working right now I have some elbow issues that I'm kind of cranky so I want to keep up my high intensity strength training but I'm doing targeted work on my wrist my wrist flexion and extension and bicep curls two times out of the week and I'm keeping up one time out of the week for heavier bicep curls so I can still get that stimulus but ultimately offload a little bit and kind of usher myself into recovery but if we understand a principle-based approach through local restriction and you're going to you're going to feel very comfortable with sliding bfr in here sliding it out taking it out because you're hey I'm a little more efficient and that's really what we spend a lot of time on in in the courses that I teach online but also in in the courses that I give to other physical therapists in the United States as well as I'm very fortunate to be teaching in Europe as well so awesome thanks so much that this was really insightful I think it gives us a lot to think about and I'm glad that we kind of deciphered some of the misinformation in that that's out there you know and how you can apply some of this research I encourage others to read the article that Nick wrote and and actually you can google his name and he's written quite a few articles on BFR so he's you know he wrote a piece actually in our in our bodybuilding special edition in 2020 they wrote an article on BFR training in the Journal of Strength and Conditioning um actually Strength and Conditioning Journal rather by the NSPA and there's a section specifically for it you can use it for physique enhancement and it kind of covers some of the basic literature around there so there's a lot of good information out there and uh please thank you for joining us Tony have anything else to add no I'm sorry for the audio but thank you so much for for joining us today and your your expertise and yeah thank you for everyone watching and if anybody has any questions about anything that we didn't cover feel free to DM me on Instagram that's probably the easiest way just because I'm more responsive there and I'd be happy to answer any questions point you in the right direction you know other researchers if you're interested and I follow their work or you know you really want to take a deep dive into BFR I'd be happy to point to you some accessible papers that you can kind of dip your toe in and before you just jump hold hold on in for those of you who are back we'll be posting follow me get a performance for you so you can also follow Dr. Roy at the HPM is that right uh that is correct we'll have link uh or link in bio Tony I think you cut out again but I think you're saying uh follow any isn't performance if you don't you don't do so uh Nick tell us your Instagram handle real quick yeah the the HPM or they can follow the BFR pros as well all right and then our course shame with plug if you're interested BFR training dot com we have a ton of areas of where I've been published and links to all those papers and you know if you're watching this this podcast this uh Instagram live later and you want a discount code just DM me and I'll happily provide you one and again thank you all for the platform and I hope to continue to help you know grow Nazm in whatever way is required of me yeah and please follow us on NASM performance we we're going to post this a little bit later that the recording will be up and then please feel free to share and thank you Tony for for having us uh sorry we had that bad connection but hey we made it we made it work today thanks everyone all right thank you bye