Blood Flow Restriction (BFR) – Blog

It usually takes approximately 6 weeks for the fracture to heal, during this time, it is imperative that the elbow is not stressed by heavy lifting. On the other hand, it is equally as important to start to exercising as soon as possible, in order to regain normal ROM.

In this case, after the initial examination for potential displacements, dislocations, injury to blood vessels and nerves no surgical intervention was needed and only partial immobilization was prescript by the physician:

By early contralateral resistance training for the uninjured arm, you can attenuate the loss of muscle mass and strength by cortical, subcortical and spinal level transfer. Using machines with adjustable weights are probably most convenient, with the injured limb using Low-load BFR and the opposite arm performing the same exercise with higher load and fewer reps in the resting periods (30-45 s.). By combining both training modalities, we’re achieving the potential benefit from both a central neurological and a peripheral muscle perspective.

The obvious benefit of using BFR is retaining strength and muscle mass with low loads, protecting the fracture. But additionally, it is imperative for fracture that the bone reabsorption (osteoblastic activity – breaking down bone) does not exceed bone formation (osteoclastic activity). Some BFR training studies showing that the cell swelling increases load around the fracture site, creating a measurable increase in bone formation markers and a decrease in bone reabsorption markers.

Though, this potential specific effect of BFR on bone formation is still very preliminary. It is important to gradually increase activity and load as the pain and swelling subside so the bones can achieve their preinjury strength. As a rule of thumb, do the exercises with high frequency, but low volume even though the elbow is often stiff and painful, it is important to continue progressing for a successful rehab.

Source:

Cancio et al. (2019) Blood Flow Restriction Therapy after Closed Treatment of Distal Radius Fractures.

Carroll et al. (2006) Contralateral effects of unilateral strength training: evidence and possible mechanisms.

Bittar et al. (2018) Effects of blood flow restriction exercises on bone metabolism: a systematic review.

The full exercise selection consists of moderate load resistance training, balance and low-load Blood Flow Restriction (BFR) training with Leg Cuffs V3 as displayed.

The PCL is located behind the ACL, comprised of 2 bundles to synergistically create antero-posterior stability within the knee (avoiding the shin bone to glide backwards relative to the thigh).

The main functional goal should be active stability which is essential for active work-life and return to sport when applicable. As the quadriceps is agonistic to the PCL, an important sub-goal should be to strengthen this muscle group for a successful rehab and return to play.

In the early stage (0-10 weeks) the ligament should heal in a neutral position in a brace to regain optimal length of the ligament, additionally, there are some essential restrictions: 1. Limiting combined hamstring contraction with knee flexion, which is essential for the healing of the ligament. 2. Load management, which is important for the health of the impaired cartilage associated with the injury.

Despite the successful return to sports, the development of osteoarthritis is evident following non-operative PCL management: At 5 years following injury, 77% develop degenerative changes in the medial femoral condyle and 47% had degenerative changes in the trochlea. Because of this, it is probably not recommended to speed up the process in regards to high impact activities such as high-speed running and high-load resistance training for the first 5 and 3 months, respectively.

For this particular client, BFR was implemented at the early stages fitting the Leg Cuff above and beneath the knee brace to limit flexion to 90 degrees during knee extension and closed chain exercises like squats etc.

Considering the relative unpleasant long-term prognosis on cartilage and meniscal health i.e. degenerative changes, the rational for using BFR and low-load exercises even at later stages seems apparent.

Source:

Strobel et al. (2003) Arthroscopic evaluation of articular cartilage lesions in posterior cruciate ligament—deficient knees.

Velde et al. (2009) Analysis of tibiofemoral cartilage deformation in the posterior cruciate ligament-deficient knee.

physio-pedia.com/Non-operative_Treatment_of_PCL_Injury.

Blazey (2018) Blog post – Blood flow restriction: miracle return to play adjunct or therapy fad?

Arthritis is the swelling and tenderness in one or several joints. The symptoms of arthritis are pain, stiffness, swelling, redness and/or decreased range of motion which typically worsen with age. The most common type of arthritis is osteoarthritis.

Osteoarthritis causes cartilage to break down over time, beginning with the lining of the joints.

The main goals of all arthritis treatments are to reduce these symptoms and improve quality of life. Conventional resistance training is often prescribed for people suffering from arthritis, as it has shown to improve both outcomes. But for some individuals, the usual training regime can be an aggravating factor. That is why BFR Training, which is inherently low-load, has been proposed as a relevant application for people struggling to do conventional training with research also indicating this.

Worldwide estimates are that 9.6% of men and 18.0% of women aged over 60 years have symptomatic osteoarthritis and the prevalence is increasing. That is also why, it has been proposed as the most important implication for BFR on a population scale!?

Though, remember when applying BFR, this is often a novel training stimulus for the client. So, in order to achieve adherence, progression and not at least to avoid adverse advents, it is imperative that the principles of gradual exposure and the repeated-bout-effect are practiced.

In this particular case, Leg Extension and Leg press is implemented with high pressures at about (70-80% LOP) at about 20-30% 1RM. Because these exercises have shown to slightly aggravate symptoms from the knees even at low-load, which can be contraindicated, especially as this exacerbation is prolonged.

Conversely, Leg curls has not been identified as an aggravator, e.g. post exercise joint swelling or pain, when the range of motion is also controlled. Because of this a lower LOP at about 60% and a higher relative load at about 40% 1RM are utilized.

Source:

Harper et al. (2019) Blood-flow restriction resistance exercise for older adults with knee Osteoarthritis: A Pilot Randomized Clinical Trial.

Ferraz et al. (2018) Benefits of resistance training with blood flow restriction in knee osteoarthritis.

Giles et al. (2017 Quadriceps strengthening with and without blood flow restriction in the treatment of PFP.

Bryk et al. (2016) Exercises with partial vascular occlusion in patients with knee osteoarthritis a randomized clinical trial.

Segal et al. (2015) Efficacy of Blood Flow Restricted Low-Load Resistance Training in Women with Risk Factors for Symptomatic Knee Osteoarthritis.

Takarada et al. (2000) Applications of vascular occlusion diminish disuse atrophy of knee extensor muscles.

The Leg Cuff V3 has a wide velcro attachment area that allows for a custom contoured fit.

This variable-contour cuff can be adjusted to the shape of the thigh, providing a personalized fit for optimized pressure distribution during exercise.

By simply changing the placement of the velcro strap you achieve a personal fit that will accommodate any thigh shape, from cone to more straight thighs and as always with our products, One-Size-Fits-All.

Listed below are just some of the relevant specs for this updated version:

✅Dynamic Cone Fit.

✅Works with the Bluetooth Device as a convenient alternative to handheld dopplers for assessment of Limb Occlusion Pressure (LOP).

✅Same width (10cm / 4Inch) as the standard Leg Cuff and thereby calibrated for “Calculate Pressure” – accessible at training.fitcuffs.com.

✅Developed to fit 99% of all thigh sizes. (thigh circumference: 45-85cm / 17-34Inch).

✅Plugin reinforced for extreme durability.

✅Thin internal stiffener for improved fit during exercise.

✅Solid metal quick-connector for fast inflation & deflation.

✅Heavy duty nylon band for swift attachment.

✅Solid stitching & bonding.

✅Water resistant nylon material.

✅Right & Left versions – only for convenience.

Notice, that the standard or original cuffs are still available for purchase!

Listed below are just some of the relevant specs for this updated version:

✅One-Size-Fits-All: (20-50 cm) / (7.9-20 Inch).

✅Full width: 7 cm / 2.75 Inch.

✅No internal stiffener for improved elasticity and pliability.

✅New reverse velcro design for swift attachment.

✅Water resistant nylon material.

✅Extension piece to avoid pinching.

✅Plugin/coupler enforced for extreme durability.

✅Industry-leading solid metal coupler.

“They were not given to me. I paid my own money for them and I am not paid to do a review.”
“This is their complete set that comes with the hard case for everything that comes with the cuffs.”

“I came across Dr. Mario Novo, who’s like one of the world’s leading experts on BFR and an awesome guy,” .. “And he told me specifically to look at Fit Cuffs as one of the brands to look at because he really likes the ability to assess LOP, as it’s extraordinarily important..”

“So I spent a few weeks looking at dozens of different brands of bands and comparing them with certain key aspects that I learned from the studies that I read. We’ll talk about some of those. And I finally settled on #fitcuffs and I could talk literally for hours on the information that I’ve compiled..”

“.., I want to explain my process when I was shopping of why I chose Fit Cuffs over all of those other brands after all of my comparison shopping.

“I want the ability to assess LOP and I want the ability to accurately set and maintain that pressure. I need something that’s comfortable, durable and versatile.” “So I want both the safety and the efficacy of BFR bands and that they are one hundred percent dependent on the ability to accurately assess the LOP.” .. “Mostly I’m I’m choosing to just go 50% of my LOP which seems to be where most of the studies recommend.”

“Yeah, that’s it. So this is an extremely, extremely accurate and easy way to control the pressure.” .. “So to do that, the vast majority of the other brands out there require you to buy a Doppler so that you can listen to the Doppler is basically just a microphone you put on your artery.
“So what I liked about Fit Cuffs is that all of these parts are individual and they’re individually replaceable..”

“So the other brands, were more flashy, which I thought was cool, but they ultimately didn’t provide better results and they weren’t as versatile and they were more expensive..”

“So initially when I was looking at before I actually even put another brand in the cart ready to buy, I was going to buy them because they were like one hundred fifty dollars less. Then I started to actually crunch the numbers and I found that it really wasn’t that good of a deal. The reason why is that I would have to add another one hundred dollars plus to buy a Doppler because it didn’t come with any way to assess LOP..” “The Fit Cuffs Training app is free through their website (fitcuffs.web.app). It works great, nice and easy to use.”

Fit and comfort: “So you don’t want to compound just the inherent discomfort of our BFR Training with poor design e.g. poorly designed cuffs. So that’s what I really liked about Fit Cuffs, is it seems like they pay really great attention to the details.”

Durability: “I use plastic couplers every day at work with my blood pressure cuffs, but that’s because they’re designed to be disposable. So you’re going to actually be inflating and deflating these cuffs multiple times per workout, multiple times per week. So you really don’t want to skip out when it comes to these quick-connectors (couplings)”.. “So these have the metal couplings, which is awesome.” “So all in all, guys, I’m extremely pleased with the design and construction. They’re really well made with attention paid to every detail” .

“No doubt that this thing is built to last and I’m going to have this for years to come. So that being said, let’s move on to the last section, which is versatility:

“That comes that’s even more important if you’re wanting to use this in a professional setting, like a gym or rehab facility, the way that this is designed, the placement of the velcro and the fact that the other side of the velcro actually extends all the way around the cuff means that this can be used on 99% of the arms and legs out there.”

“So overall, the design of these makes them really some of the most versatile cuffs on the market.”

Leg Extension + Leg Curl + Seated Calf Raises.

Noticeably is the possibility for single-joint exercises which can be an important training modality and has been proposed as the optimal way to start off with BFR. So, keep on reading for the rational of doing single-joint exercises:

A common Jargon among the dinosaurs of health care and fitness professional’s is that movement patterns should be trained as opposed to individual muscle groups. Because single-joint exercises are mostly not a part of ADL, sports or other recreational activities, they are often labelled as nonfunctional and therefore excluded from rehab and performance programs. But as you might already know, this bold argument is somehow outdated and unnuanced.

Compared to multi-joint exercises, single-joint exercises like leg extension is unaffected by proximal fatigue occurring in the prime movers, e.g. squats favor glute max at the likely expense of quadriceps exertion. Conversely, single-joint exercises, can be a better option to reach the effective rep range unaffected by the exertion experienced in the surrounding and synergistic muscle groups.

By augmenting conventional multi-joint exercises with single-joint BFR exercises it is possible to gain specific muscle strength that is directly transferable to ADL and sports performance, above which can be achieved with multi-joint training alone.

Because low-load exercise and thereby inherently BFR, must be performed with high exertion on the targeted muscles in order to reach the state of near volitional failure, single-leg exercises can in some instances be preferable. This is particularly relevant for people unaccustomed to BFR, as single-leg exercises can be a great way acclimating to the significant stress of BFR.

Additionally, Leg curls improves stretch tolerance because of increased fascicle length through the addition of sarcomeres in series which improves the functional muscle length and has shown to be relevant for injury prevention and performance, e.g. sprint speed etc.

Source:

Schoenfeld et. Contreras (2012) Do Single-Joint Exercises Enhance Functional Fitness?

Gentil et al. (2015) Single vs. Multi-Joint Resistance Exercises: Effects on Muscle Strength and Hypertrophy.

Stien et al. (2020) Training specificity performing single-joint vs. multi-joint resistance exercises among physically active females: A randomized controlled trial.

By applying Blood Flow Restriction (BFR) muscles are simply stimulated at a lower working rate compared to Free Flow Conditions. Or alternatively, the metabolic stress and low-load exercise let’s your reach the effective rep range faster compared to conventional training.

For most people similar explanations would do the job, if not, then keep reading for a more comprehensive explanation of why BFR has proven its worth for hypertrophy!

As a rule of thumb, muscles adapts to mechanical and/or metabolic stimuli. Mechanical being the external load on the muscle whereas metabolic being the exertion of the muscle during repetitive or static work. The great thing about BFR is that you reach the state of exertion/fatigue much faster compared to conventional resistance training – BFR simply reduces the repetitions needed to build muscle by 30-50%.

When blood flow is partially restricted the transportation of oxygen is also reduced which changes the energy demand and increases the speed in which muscle fatigue occurs. This partial hypoxic (no oxygen) state means that the type 2 muscle fibers are being recruited at a rapid rate. When lactate and other metabolites accumulates because of glucose break down even more muscle fibers are being recruited.

BFR + cell swelling + mechanical tension creates metabolic stress leading to swift muscular exertion. – Activation of mTor and downregulation of myostatin, as the most important hormonal responses leading to increased protein synthesis.

Combined with the repeated bout effect e.g. regular training, we have a finale recipe for hypertrophy.

As some of the ingredients are up for debate, like cell swelling (the primary rational for passive BFR) and lactic acid as a direct anabolic pathway for collagen production (tendon health), please do not hesitate to comment!?

Source:

Klein et al. (2001) Flexor tendon wound healing in vitro: the effect of lactate on tendon cell proliferation and collagen production.

Jessee et al. (2018) Mechanisms of Blood Flow Restriction: The New Testament.

Sleboda et al. (2019). Internal fluid pressure influences muscle contractile force.

Dr. Nicholas Rolnick (2020) 13 Module Online Video Course – Blood Flow Restriction.

BFR or blood flow restriction is currently showing its efficacy as a performance optimizer in many different sports, both anecdotally but definitely also from a scientific standpoint. (Wilk et al. 2020).

Though, currently lacking any specific data on arm wrestling the potential benefit of BFR is a dead giveaway.

The popularity of arm wrestling has increased enormously in the recent years, probably because of the intense and audience friendly setup. Even though, at first glance it might seem straightforward, the sport is actually very technical e.g. positioning etc!

Thus, a substantial part of success in arm wrestling can bee contributed to raw physical ability, such as maximal strength and not at least muscular endurance.

The two main physical components can for obvious reasons be augmented by adding BFR to the sport’s specific exercises in arm wrestling. We recommend to use the standard principles for low-load BFR training, but as you can see in the video Michael is adapting some arm wrestling-specific positioning and shorter ROM.

As a relevant factor to consider, is the extremely high training volume which is paramount for all professional arm wrestlers. Because of the inherent training adaptations in arm wrestling, the rep scheme, sets and exercises can probably be much higher compared to what is normally recommended for upper body BFR. Though, the optimal way to program BFR for arm wrestling is currently unexplored.

As discussed in the latest post, BFR can be used as the primary modality in short blogs or as a finisher to your conventional workout. But for any of you that have watched arms wrestling, I would like to know your initial thoughts on how to use and program BFR for performance optimization in this population!?

Source:

Wilk et al. (2020) The Acute Effects of External Compression With Blood Flow Restriction on Maximal Strength and Strength-Endurance Performance of the Upper Limbs.

As you probably already know, low-load BFR is a great way to increase training volume and frequency without loading the joints or impairing your recovery. For the general public, we recommend to start with your conventional heavy training and finish your workout with BFR as it has some obvious advantages of low-load BFR training, especially in situations of joint pain and high-volume training.

Next, because BFR works best with low-load, use 30-50% of the load you’d usually use for a standard set of 10-15 reps but shorter inter-set rest, as the short rest periods will further increase the rate of exertion and increase the subjective feeling of the pump! You can expect large initial effect, e.g. 2-3 weeks of consecutive training.

When utilizing BFR as a finisher we recommend BFR at a low frequency as only 2-3 times a week with 1-3 upper and/or lower body exercises immediately after performing your main workout as a finisher:

As an alternative to BFR-finishers, is the application of BFR in alternating weeks, swapping with your usual workout routine: We recommend BFR in alternating weeks/days with a high frequency as 1 time per day or even 2 times a day but only for short periods (1-3 weeks).

BFR coupled with low-load exercise increases cell swelling and metabolic stress and let’s your reach the effective rep range faster compared to conventional training and with less mechanical tension.

Source:

Lowery et al. (2013) Practical blood flow restriction training increases muscle hypertrophy during a periodized resistance training programme.

Rolnick et Schoenfeld (2020) Blood Flow Restriction Training and the Physique Athlete- A Practical Research-Based Guide to Maximizing Muscle Size.

💥 Full width is 7 cm (2.7 inch) which is the same as the original Arm Cuff.

💥 Fits about 99% of all arm sizes, specified as upper arm circumference between 20-50 cm (7.9-20 Inch).

💥 Works perfectly in conjunction with the Bluetooth Device for assessment of Limb Occlusion Pressure (LOP) and the “Calculate Pressure” module at training.fitcuffs.com.

Though, while it may seem a little ridiculous at first glance, BFR consistently outperforms conventional training with low loads on about any relevant parameter such as strength and muscle mass.

It is far from a necessity to do advanced and “functional” exercises and often the simplest exercises are the way to start, especially in regards to muscle mass:

0:00 Hack Squat

0:17 Leg Curl

0:33 Leg Extension

If you´re a BFR novice and you do not have any relevant injuries, we recommend to use such or similar exercises as exemplified in the video to increase muscular strength and mass.

But please mind! If this is your or your clients very first time doing BFR, ask for any relevant chronic conditions, e.g. hyper- or hypotension. Then implement the principles of gradual exposure and progressive overload into your programming, as this is key for both adherence, safety and effectiveness:

We recommend doing only one exercise at about 15-30% 1RM for 30x15x15x15 reps without reaching failure. Then in the following weeks progress your exercise selection, intensity/load, and for most people it would be advisable to deflate the cuffs between exercises for a start.

Additionally, we recommended that the pressure is set relative to the individual, that can be controlled by measurement of Limb Occlusion Pressure “LOP” or for Fit Cuffs, by the “Calculate Pressure” as both modules are readily available at ficuffs.web.app. Basically, the amount of pressure needed to stop blood flow is highly dependent cuff width, the size of the limb in regards to circumference and to a less degree body composition. Though, it should also be considered that BFR has shown to be effective and safe across a wide range of relative pressures i.e. 40-80% LOP.

Above and beyond, by utilizing the principles of gradual exposure you can avoid severe DOMS, numbness, bruising, dizziness (see exercise pressor reflex) and not at least, attain adherence for BFR Training.

Source:

Spranger et al. (2016) Blood flow restriction training and the exercise pressor reflex: a call for concern.

Jesse et al. (2016) Letter to the editor: Applying the blood flow restriction pressure: the elephant in the room.

Spranger et al. (2016) Reply to “Letter to the editor: Applying the blood flow restriction pressure: the elephant in the room”.

Presentation by Dr. James P Fisher. The Exercise Pressor Reflex – available at rigshospitalet.dk.

Additionally, the Bike Tests can be used to predict VO2 Max, Fitness Level and Watt Max, which is commonly known as “indirect tests” for Aerobic Fitness. A comprehensive protocol for each test can be located directly at training.fitcuffs.com –> “Bike Tests”.

Many clinician and trainers are interested in determining an individual’s Aerobic Fitness but are limited in their use of “direct tests”. The tests can be performed on any type of exercise bike but preferable on a Watt-bike Cycle Ergometer. Subsequently, you can use the build-in slider to set the intensity relative to either Watt Load or Work Pulse Beats Per Minute (BPM) i.e. Heart Rate Reserve (HRR).

The features consist of 3/4 different tests build into the same interface. All tests seem to have less than 10% error associated with them in predicting VO2 Max (1) and a very high ability to detect any relevant change of Aerobic Fitness:

a. By only using Age, the app will estimate your Max Pulse and Resting Pulse. This is sufficient to use the slider-functionality to set the intensity relative to HRR i.e. BBP. For a more precise estimation of your HRR you can add your Max Pulse and Resting pulse.

b. The Submaximal Bike Tests includes a rather simple “one-point-test”, that can be used to estimate your VO2 Max, Fitness Level and Watt Max. To use this feature, you need to find your steady-state-pulse at a corresponding Watt Load, i.e. Load 1 and Pulse 1. Add your Resting Pulse and Max Pulse to obtain a more valid estimation of your actual Aerobic Fitness (2,3,4).

c. For improved estimation of your Aerobic Fitness, you can perform the same test but adding a higher load and higher pulse i.e. Load 2 and Pulse 2, aka. “two-point-test” (2,3,4).

d. But the Golden standard for most individuals is the Watt Max Bike Test. This is performed by a similar progressive protocol, but this test is much harder as you must go all out and reach the point of absolute failure in order to obtain a valid test result. this maximum test, should not be used in at risk populations i.e. heart or respiratory conditions, without approval from a physician. As a rule of thumb for the general public, if you’re not used to do strenuous exercise, perform the test after gradual exposure to near maximal intensity aerobic exercise.

Disclaimer: Always consider the safety of the tests in respect to age, training condition, etc., and the test–retest reliability and validity (1). The formulas from the Bike Test module can be found at (4).

Source:

(1) Grant et al. (1999) The Prediction of Vo2max: A Comparison of 7 Indirect Tests of Aerobic Power.

(2) Astrand et Rodahl. (1986) Textbook of Work Physiology: Physiological Bases of Exercise (3rd ed.). New York.

(3) Astrand et Ryhming. (1954) A nomogram for calculation of aerobic capacity (physical fitness) from pulse rate during submaximal work.

(4) Beyer et al. (2010) Træning – i forebyggelse, behandling og rehabilitering. Munksgaard Danmark.

You should also stay tuned for a follow-up post with a comprehensive explanation of the different tests and the essential research on the near linear relationship of Watts and Working Pulse. As this is fundamental for these “indirect tests”, i.e. estimation of VO2 Max, Fitness Level and Watt Max.

0:32 Backwards Running.

Straight running drills can be done with a steady pace or as intervals at submaximal velocity i.e. 50-90% maximum sprint speed, with or without backwards running which focuses on the glute and hamstrings.

The Bilateral Hurdle Hop is a simple plyometric movement that combines muscle fatigue and coordination. Just remember to land and take off with both feet at the same time with minimal contact time.

Lateral Shuffle: Without crossing feet, shuffle laterally right over each hurdle, leading with one leg so each foot touches once between hurdles.

Training with BFR is a well‐recognized strategy for promoting muscle hypertrophy and strength. However, its potential to enhance muscle function during sustained, anaerobic type exercise has also been explored in several research papers as presented in the latest post (the complete BFR guide). It seems that BFR performance-training, has its relevance in later stage rehab and to improve performance in the uninjured athlete.

The partial restriction of blood flow to the legs during these and similar workouts, raises the oxygen and energy expenditure with a higher rate of fatigues compared to conventional drills. BFR seems to improve several parameters of performance, but the adaptations after BFR-running seems to be primarily muscular (peripheral) rather than cardiovascular (central).

As BFR training is less time consuming and puts less strain on the tendons and joints this can be relevant for athletes during periods of strenuous exercise e.g. in season.

We recommend that this or similar BFR augmented drills, are performed after conventional sports practice/athletic training or as alternating weekly/daily with or without BFR, simply by changing intensity and exercise time.

As a rule of thumb, duo to the novel training stimuli of BFR, remember to use the principles of gradual exposure, in regards to exercise time, intensity and pressure (mmHg) to avoid rhabdomyolysis. In addition, it seems that training intensity and pressure are important factors to progress for optimal aerobic, anaerobic, and muscular development.

0:00 Back Squat – 0:20 Cross-behind Lunge. – 0:40 Romanian Deadlift.

Cross-behind lunge focuses on strengthening the glutes, quads, and calves. It has also been proposed that the large range of motion of the hip, augments glute strength and muscle gains.

Though, the glute muscle is obviously upstream relative to the cuff (proximal), it appears that BFR is effective for improving glute size and strength, when neither clinical or practical feasible to use higher loads.

Proximal hypertrophy is a common observation in multi-joint BFR training exercises in both aerobic and resistance training protocols, but the reasons for hypertrophy of the gluteus are unclear and several explanations exist.

If we compare the rational for proximal gain of the glute in the BFR-Squat vs. BFR-Romanian deadlift, it can be speculated that the underlying mechanisms are somehow different:

The accelerated fatigue of the muscles distal to the cuff require a larger contribution of the muscles proximal to the cuff. Because of a higher motor unit recruitment may be required to maintain sufficient force generation as a synergistic action of the knee and hip muscles that increases the demand of the proximal muscles.

This is the most common explanation of why the conventional BFR-squat movements can be effective for proximal gains. – With the glutes being the prime hip extensors in the squat, and hamstrings being secondary, i.e. stabilizers of the knee, the magnitude of proximal effect is probably attenuated by the rapid fatigue of the quads and thereby the limiting factor.

For the hinge pattern e.g. Romanian deadlift, the knees are almost fully extended causing the hamstrings to be a prime mover along with the glutes. But when you pair this movement with BFR, it can be hypothesized that the hamstrings get fatigued faster compared with No-BFR deadlifts, making the glutes the primary hip extensor and reaching it’s full potential for growth.

Source:

Bowman et al. (2019) The Proximal and Distal Effects of Blood Flow Restriction Therapy on Upper and Lower Extremity Strengthening: A Randomized Controlled Trial.

Abe et al. (2005) Skeletal muscle size and circulating IGF-1 are increased after two weeks of twice daily “KAATSU” resistance training.

Luebbers et al. (2014) The Effects of a 7-Week Practical Blood Flow Restriction Program on Well-Trained Collegiate Athletes.

If you haven’t already spotted the recent post, we advise you to have a quick look. In the present post we describe some additional guidelines for BFR in Rehab, BFR with conventional exercise and BFR in sports performance.

Regarding BFR as a performance modality, it should be acknowledged that the different protocols effects many of the same parameters. It should also be noticed that the science in BFR for performance is a less explored field of research and many different protocols have been proposed. So, as this is still very preliminary and optimized training protocols will undoubtedly be discovered in the nearest future.

It should also be considered, that regular low-load resistance BFR training has proven it worth as a performance enhancer, relative to the athletes baseline form. Another relevant thing to consider, is the expected inter-individual response to different protocols and importantly, personal preferences for different exercise modalities.

Some of the protocols found in the research utilize very high intensity and high relative pressure (% of Limb Occlusion Pressure). That is why we recommend gradual exposure of both volume and intensity, as the key to avoid adverse events and training adherence.

If you have picked up anything not matching the current science or your own practical experience, please let us know in the comments!?

Additionally, if you find we have missed mandatory information especially regarding safety, please also comment below, so we can continue to improve this complete guide!?

Source:

Rolnick et Schoenfeld (2020) Blood Flow Restriction Training and the Physique Athlete- A Practical Research-Based Guide to Maximizing Muscle Size.

Hansen et al. (2020) Effects of alternating blood-flow restricted training and heavy-load resistance training on myofiber morphology and mechanical muscle function.

Loenneke et al. (2012) Blood flow restriction: an evidence based progressive model (review).

Barbalho et al. (2018) Addition of blood flow restriction to passive mobilization reduces the rate of muscle wasting in elderly patients in the intensive care unit: a within-patient randomized trial.

Bennet et al. (2018) Effects of Blood Flow Restriction Training on Aerobic Capacity and Performance: A Systematic Review.

Amani et al. (2019) Blood Flow Restriction During Futsal Training Increases Muscle Activation and Strength.

Behringer et al. (2017) Low-Intensity Sprint Training With Blood Flow Restriction Improves 100-m Dash.

Christiansen et al. (2019) Cycling with blood flow restriction improves performance and muscle K+ handling and blunts the effect of antioxidant infusion in humans.

This is indeed not a finite version, as more research is being published at a rapid rate, better protocols will certainly be discovered in the newest future.

But for your own expense, be aware, as this video is not for the virginals, as some skin and partial nudity may occur.😉 But I can insure you, for the indefinite Viking i.e. Oliver Price, this is definitely not the first time showing off some impressive physique.

Joking aside, this is actually a great way to display the vascularization and decolorization that is associated with muscle contractions combined with appropriate partial restriction of blood flow i.e. 40-80% LOP. That is when arterial inflow is partially restricted and venous outflow is completely restricted.

Though, for some people it may seem to extreme, but this is actually a common phenomenon in people with low body fat.

In the original Kaatsu protocol for what they now label as blood flow moderation, this is actually a part of their direct indicators of a beneficial BFR stimuli. On the other hand, if you or your client turn pale on the restricted limbs, this is a sign of near or complete occlusion, which is of course contra indicated and should be avoided during BFR training.

Regarding this ingenious home training setup, you can see how some water bottles and a broom can be turned into a dumbbell and a barbel, respectively.

For people who are used to conventional resistance training, aim for 30 reps followed by at least 3 sets of 15-20 reps and progress by doing at least the last set to failure and/or shorter inter-set rest periods (30-60 seconds).

So, when the usual dumbbell rack is not an option and the relative load cannot be identified, this is a convenient way to progress you low practical BFR Training.

Considering 12 x 1.5 kg water bottles used in the last exercise and as a general recommendation, exercises with a relative load above 50% 1RM should be applied without BFR for optimal effectiveness.

By augmenting your conventional exercise selection by Fit Cuffs, you got access to an effective, convenient and significantly less time demanding workout:

0:02 Bodyweight Dip.

0:05 Leg Elevated Chest Press.

0:07 Reverse Flyers.

0:13 Dumbbell Chest Pres.

0:20 Seated Dumbbell Curls.

0:26 Added load by stacking a tire with dumbbells.

0:44 Upright Rows.

0:48 Standing Dumbbell Curls.

BFR can be relevant for athletes, gym rats, and not to forget, in musculoskeletal rehab where high-load may initially be contraindicated. Basically, BFR lets you become stronger, with less stress on the tendon and articular structures, which is relevant for periods of deloading or as a finisher after a conventional workout.

Both programming modalities can be equally as effective and during this time, with limited access to the gym, BFR is probably more pertinent than ever. But as presented in the previous two posts, with reference to the newest and relevant data, it seems appropriate, that BFR is primarily used as a finisher, or as a substitute for shorter periods (<4-6 weeks).

We especially recommend BFR as a part of a periodization programming, for individuals with high volumes of resistance training or for athletes with high intensity weight bearing activities. Simply applied as alternating weeks of either high-load training or low-load BFR training followed by weeks as a short finisher to a high-load training session.

source:

Bagley et al. (2015) Is Blood Flow Restriction Training Beneficial for Athletes?

Scott et al. (2015) Blood flow restricted exercise for athletes: a review of available evidence.

This has been explored in a recent RCT from University of southern Denmark and in a practical research-based guide from Rolnick & Schoenfeld.

In the RCT, the researchers compared the effect of lower-limb block-structured training, consisting of alternating weeks of BFR training and conventional Heavy-Load resistance training (BFR+HL) vs. only (HL).

Methods: 18 active young participants were randomized to either 6-weeks (22 sessions) of structured training alternating weekly between BFR (20% 1RM) + HL (70-90% 1RM) vs. only HL (70-90% 1RM).

Outcomes: Maximal isometric knee extensor strength (MVC) and muscle biopsies (VL) as myofiber cross-sectional area (CSA), myonuclear (MN) number and satellite cell (SC) content.

Results: MVC increased in both groups (BFR+HL: +12%) vs. (HL: +7%). Type 2 CSA increased similarly in both groups (16%), while gains in type 1 CSA were only observed in HL (12%).

Conclusion: Conventional HL can periodically be replaced by low-load BFR without compromising gains in maximal muscle strength.

In the practical research-based guide, you will find an evidence-based recommendation on how to maximize hypertrophic potential with the implementation of BFR into a conventional program.

From the comprehensive amount of original research on this topic, it seems legit to add 1–2 exercises per target muscle group at the end of a heavy-load training session, to preferentially stress type 1 muscle fibers as a “finisher”.

This perspective on muscle fiber differentiation seems valid as the authors have discovered this from at least 2 original research articles, but this is actually the direct opposite trend that was discovered in the RCT!

Any thoughts or explanation, as why the RCT found that only the conventional High Load group gained type 1 muscle fiber hypertrophy?

Secondly, what should be considered when choosing to either implement BFR as alternatingly weeks/days (the RCT) vs. supplement to conventional training as a finisher?

Source:

Hansen et al. (2020) Effects of alternating blood-flow restricted training and heavy-load resistance training on myofiber morphology and mechanical muscle function.

Rolnick et Schoenfeld (2020) Blood Flow Restriction Training and the Physique Athlete- A Practical Research-Based Guide to Maximizing Muscle Size.

0:00 Step Up. 0:10 Romanian Deadlift. 0:22 Squat. 0:34 Kneeling Squat. 0:44 Reverse Lunge.

During this point of time with many gyms being closed, it becomes inherently more interesting, whether BFR training can substitute conventional high load training?

It seems, that for most people it actually can be just as effective in regards to strength and muscle mass, but tendon health is a less explored field of research.

So, in a new pilot study from University of Copenhagen, the researchers have investigated whether BFR can help to improve tendon health in people with chronic Jumper’s knee (JS).

The rational for using BFR on this population, is that O2 deficiency in the muscle causes lactic acid, that seems to stimulate the formation of collagen protein in the tendon.

Protocol: 7 participants with chronic JP trained 6 sets of both single leg-press and single leg-extension at 30% 1RM until volitional failure for only 3 x 3/weekly.

Results: They experienced about as much progress as normally expected after 12 weeks of heavy slow resistance (HSR) training, which is the current recommended treatment for JS. As, significantly less pain (NRS) was reduced by 50% during single-leg decline squat testing, ultrasound scanning of tendon, showed vascularity diminished by 31 %.

Though, considering the small sample size, it’s very preliminary whether BFR training really has this rapid effect on JS.

If we compare these preliminary findings with the results from Centner et al. (2019), it seems valid that BFR training can be used as the primary modality in the rehabilitation of tendon related pains/disorders such as tendinopathy. But reversely, if we compare this to earlier work by Kubo et al. (2006) they did not find any relevant change on the tendon level. As BFR only increased muscle strength and size without the increment of tendon stiffness or force–elongation, but the high-load leg achieved the desirable improvement in tendon stiffness.

Any thoughts on BFR as the primary training modality or treatment of chronic tendon disorders such as tendinopathy?

Skovlund et al. (2020) The effect of low-load resistance training with blood flow restriction on chronic patellar tendinopathy – a case series.

Centner et al. (2019) similar morphological and mechanical Achilles tendon adaptations compared with high-load resistance training.

Kubo et al. (2006) Effects of low-load resistance training with vascular occlusion on the mechanical properties of muscle and tendon.

Exercises in display:

0:16 Walking Lunge
0:20 Squats Jump
0:27 Push-up
0:42 Inch Worm
0:39 Horizontal Jump Squat
0:49 Lateral shuffle

So, as long as the gym is closed, we advise you to utilize your favored BFR tool and move your exercise routine to urban areas, nature or for some higher restricted regions as home training.

But if you do not supplement your BFR training by any kind of external resistance tool, like elastic bands etc., most people need to consider how to fatigue of both type 1 and type 2 muscle fibers.

As a rule of thumb, to target type 1 muscle fibers, you need to train at lower intensities, but perform higher reps and probably also more sets.

Subsequently, you can also consider the force-velocity relationship like doing force-full movements like sub-maximal Squat Jumps to achieve the fatigue of type 2 fibers at a rapid rate. This is because, if exercises are conducted at higher velocity this leads to greater exhaustion of fatigue sensitive type 2 fibers.

Any thoughts or precautions on BFR in combination with higher velocity based exercises like Jumping?

Spendiff et al. (2002) Effects of fatigue on the torque-velocity relation in muscle.

You can check the video on how to register a user, calculate pressure, tab in Limb Occlusion Pressure (LOP) and the last 10 s. on how to download it for offline availability. You can access the app from the homescreen just as an any other app on android devices and Iphones.

We have developed the algorithm from the comprehensive science and data on the predictors of Limb Occlusion Pressure (LOP), for you to enjoy Effective, Save and Convenient BFR Training.

We do not recommend to use arbitrary pressures, neither do we recommend a default pressure, though 80 mmHg and 100 mmHg for the upper and lower body, respectively, would be applicable for about 90% of all people.

Our goal pressure extracted from the algorithm is 40-70% LOP and 50-80% LOP, for the upper and lower body, respectively. Currently, the new progressive web app “Fit Cuffs Training” can predict this goal pressure for +95% of all people.

From the comprehensive research articles, it seems that limb circumference can explain about 50-70% of the variance in LOP. But the width of the cuff is actually the most important factor to consider, that is also why this App is only applicable for Fit Cuffs®.

Thigh circumference is undoubtedly the biggest anthropometric predictor of arterial occlusion, but other factors are also of importance:

It seems that both gender, age and body composition influence the percentage of blood flow that is restricted. That is why these predictors are included in the algorithm, along with training condition, as we find this of importance for Ratings of Perceived Exertion (RPE).

So, when LOP is not accessible, we recommend to use calculated pressure. Every time you tab-in LOP and calculate a corresponding pressure for either upper or lower body, you actually help us to improve the algorithm in the future.

“.. cuff pressures should be largely based on thigh circumference and not on pressures previously used in the literature.” (Loenneke et al. 2012)

Source:

Tuncali et al. (2006) A New Method for Estimating Arterial Occlusion Pressure in Optimizing Pneumatic Tourniquet Inflation Pressure.

Tuncali et al. (2018) Tourniquet pressure settings based on limb occlusion pressure determination or arterial occlusion pressure estimation in total knee arthroplasty.

Loenneke et al. (2012) Effects of cuff width on arterial occlusion implications for blood flow restricted exercise.

Loenneke et al. (2014) Blood flow restriction in the upper and lower limbs is predicted by limb circumference and systolic blood pressure.

Brown et al. (2018) Factors affecting occlusion pressure and ischemic preconditioning.

Hunt et al. (2016) The influence of participants characteristics on the relationship between cuff pressure.

Jessee et al (2016) The Influence of Cuff Width, Sex, and Race on Arterial Occlusion Implications for Blood Flow Restriction Research.

Jobbágy & Varga (2014) Digitális Tankönyvtár. Biomedical Instrumentation. Indirect blood pressure measurement methods.

Karabulut (2011) The effects of different initial restrictive pressures used to reduce blood flow and thigh composition on tissue oxygenation of the quadriceps.

You can check the video on how to register a user, calculate pressure, tab in Limb Occlusion Pressure (LOP) and the last 10 s. on how to download it for offline availability. You can access the app from the homescreen just as an any other app on android devices and Iphones.

We have developed the algorithm from the comprehensive science and data on the predictors of Limb Occlusion Pressure (LOP), for you to enjoy Effective, Save and Convenient BFR Training.

We do not recommend to use arbitrary pressures, neither do we recommend a default pressure, though 80 mmHg and 100 mmHg for the upper and lower body, respectively, would be applicable for about 90% of all people.

Our goal pressure extracted from the algorithm is 40-70% LOP and 50-80% LOP, for the upper and lower body, respectively. Currently, the new progressive web app “Fit Cuffs Training” can predict this goal pressure for +95% of all people.

From the comprehensive research articles, it seems that limb circumference can explain about 50-70% of the variance in LOP. But the width of the cuff is actually the most important factor to consider, that is also why this App is only applicable for Fit Cuffs®.

Thigh circumference is undoubtedly the biggest anthropometric predictor of arterial occlusion, but other factors are also of importance:

It seems that both gender, age and body composition influence the percentage of blood flow that is restricted. That is why these predictors are included in the algorithm, along with training condition, as we find this of importance for Ratings of Perceived Exertion (RPE).

So, when LOP is not accessible, we recommend to use calculated pressure. Every time you tab-in LOP and calculate a corresponding pressure for either upper or lower body, you actually help us to improve the algorithm in the future.

“.. cuff pressures should be largely based on thigh circumference and not on pressures previously used in the literature.” (Loenneke et al. 2012)

Source:

Tuncali et al. (2006) A New Method for Estimating Arterial Occlusion Pressure in Optimizing Pneumatic Tourniquet Inflation Pressure.

Tuncali et al. (2018) Tourniquet pressure settings based on limb occlusion pressure determination or arterial occlusion pressure estimation in total knee arthroplasty.

Loenneke et al. (2012) Effects of cuff width on arterial occlusion implications for blood flow restricted exercise.

Loenneke et al. (2014) Blood flow restriction in the upper and lower limbs is predicted by limb circumference and systolic blood pressure.

Brown et al. (2018) Factors affecting occlusion pressure and ischemic preconditioning.

Hunt et al. (2016) The influence of participants characteristics on the relationship between cuff pressure.

Jessee et al (2016) The Influence of Cuff Width, Sex, and Race on Arterial Occlusion Implications for Blood Flow Restriction Research.

Jobbágy & Varga (2014) Digitális Tankönyvtár. Biomedical Instrumentation. Indirect blood pressure measurement methods.

Karabulut (2011) The effects of different initial restrictive pressures used to reduce blood flow and thigh composition on tissue oxygenation of the quadriceps.

In this summary we present the results from a newly published paper by Christiansen et al. 2020 and two preceding papers with the same exercise protocol:

AIM: The effect of BFR-interval training on different parameters of performance.

PROTOCOL: 10 Well-trained men completed 6 weeks of interval cycling with one (BFR-Leg) vs. (No-BFR-Leg), workload was matched between legs. The participants trained 3/week for 6 weeks. 5-min warm-up at 30% of maximum workload (Wmax) followed by 2 min of rest.

3 periods of 3 x 2-min cycling bouts were performed separated by 1 min and each period by 2 min of active recovery pedaling. Complete exercise time 24 min. Target intensity of the 1., 2. and 3. period was 60%, 70%, and 80% Wmax, respectively, with a personal preferred cadence.

BFR-Leg only: Pressure ~178 mmHg, deflation immediately after every exercise bout (intermittent BFR).

RESULTS: Time to exhaustion during exhaustive exercise, BFR-Leg ~21% vs. NO-BFR-Leg ~10%. Acute arterial blood flow in BFR-Leg ~52% lower during exercise and 308% higher during recovery vs. no change in No-BFR-Leg. Chronic arterial blood flow before, during and after knee-extensor tests did not change in the NO-BFR-Leg, but improved in the BFR-Leg. Resting femoral artery diameter increased only in BFR-Leg ~4%.

Power output during knee-extensor exercise, BFR-Leg vs. No-BFR-Leg improved ~20% and ~9%, respectively. Knee extensor exercise performance: BFR-Leg vs. No-BFR-Leg improved ~23% and ~11%, respectively.

Venous-arterial K+ difference. Simplified as no change in the No-BFR-Leg, but increased in the BFR-Leg. Thigh oxygen delivery for the BFR-Leg (~23% and ~13% in sub-max and near-max tests, respectively). No significant change in the No-BFR-Leg.

Reduced lactate release at both intensities (~34% and ~16% in both conditions, respectively). No change in No-BFR-Leg.

CONCLUSION: Well-trained individuals can increase V̇O2max and time to exhaustion by use BFR-interval training, explained by various physiological mechanisms.

Christiansen et al. (2020) Training with blood flow restriction increases femoral artery diameter and thigh oxygen delivery during knee-extensor exercise in recreationally trained men.

Christiansen et al. (2019) Blood flow-restricted training enhances thigh glucose uptake during exercise and muscle antioxidant function in humans.

Christiansen et al. (2019) Cycling with blood flow restriction improves performance and muscle K+ handling and blunts the effect of antioxidant infusion in humans.

0:05-Flexion. 0:12-Abduction. 0:20-External rotation (ER) at 0°. 0:30-Internal rotation (IR) at 0°. 0:39-IR at 90°. 0:46-ER at 90°.

We find this interesting as a relatively new paper (only preliminary results presented), discovered that BFR for low-load resistance exercise to be effective for proximal gains i.e. RCs (1).

PURPOSE: If BFR promote greater increases in strength, muscular endurance, and lean mass for the RCs compared to exercise alone (No-BFR). Secondly, if BFR during acute low-load resistance exercise increases activation of RCs.

METHODS: (RCT) Eighteen healthy adults randomized into 2 groups (BFR vs. No-BFR).

Each group: 8 weeks (2/wk) as 4 low-load RCs resistance exercises at 20% of 1RM: Cable – external rotation (ER) & internal rotation (IR). Dumbbell – scaption & side-lying ER.

1 set/30reps followed by 3 sets/15reps (30s inter-set rest, 2min inter-exercise rest). For progression, 1lb (0.45 kg)/week if all repetitions where achieved.

Only BFR: Intermittent BFR stimuli (only during exercises) at 50% LOP.

RESULTS: Lean Mass: Arms BFR vs No-BFR, 8.15% vs. -0.43%, respectively. Shoulders BFR vs No-BFR, 28.10% vs. 11.23%, respectively.

Strength: Assessed in 6 different positions comparing dominant and non-dominant arm separately: For the dominant arm, all positions showed a strong trend for BFR be superior. ≈ 5-20% greater relative improvements for BFR vs. No-BFR.

Exercise Volume: 7/7 follow-up tests in favor of BFR.

Mean EMG activations: Same relative activation pattern for Infraspinatus, but BFR seemed to be superior for Teres Minor.

CONCLUSIONS: BFR augmented RCs exercises seems favorable. Possible due to a greater activation of shoulder musculature.

Discussion: The exercise intervention was designed in favor of BFR. The load was only 20% 1RM with a standardized rep-scheme and only allowed for 1lb (0.45 kg) once/week for progression. – Any thoughts?

An interesting sub-finding was that only the dominant arm for the BFR-group experienced a greater relative improvement in strength. – Any thoughts?

Source: Lambert et al. (2019) B.F.R. For Proximal Benefit: Blood Flow Restriction Therapy For The Shoulder?

But when your local gym is not an option, you have to consider several factors for you to maintain muscle mass or strength. For most gym rats it should be achievable to maintain muscle mass in this lockdown situation, but it becomes inherently more difficult when your goal is hypertrophy. In regards to absolute strength, it becomes even more difficult to retain and especially increase strength.

The amount of load and volume is obviously highly dependent on your current training status. But for a vast generalization, maintenance of muscle bulk should be obtainable for most people, especially with BFR and in less time!

As a proxy for estimation of 20-40% of 1 RM, these basic simple principles apply:
As rule of thumb, aim for 20-35 reps to voluntary failure for the first set, followed by 3 sets of 10-20 reps with an inter-set rest period of 30-45 s.

When considering the minimum effective volume, it becomes more difficult to generalize, but in regards to hypertrophy, more IS better! On the other hand, if your goal is to maintain strength, less volume is needed. Aim for at least 30 % 1 RM with every set near failure. Some evidence suggests that BFR can be optimized by exercising the same muscle group 1 or even 2 times a day in periods of 3 weeks.

Considering these principles for BFR, bodyweight squats is insufficient for most people, but can easily be progressed by means of:

External resistance with an elastic band ➡️ Unilateral like Bulgarian split squat ➡️ Higher relative pressure (mmHg).

For regression of push-ups, just elevate the hands relative to the feet as displayed. Please also remember, that all exercise is better than no exercise! And BFR is Better For Results – when load is low!

But when your local gym is not an option, you have to consider several factors for you to maintain muscle mass or strength.

For most gym rats it should be achievable to maintain muscle mass, but it becomes inherently more difficult when your goal is hypertrophy. In regards to absolute strength, it becomes even more difficult to retain and especially increase strength.

The amount of load and volume is obviously highly dependent on your current training status. But for a vast generalization, maintenance of muscle bulk should be obtainable for most people, especially with BFR and in less time!

As a proxy for estimation of 20-40% of 1 RM, these basic simple principles apply:

As rule of thumb, aim for 20-35 reps to voluntary failure for the first set, followed by 3 sets of 10-20 reps with an inter-set rest period of 30-45 s.

When considering the minimum effective volume, it becomes more difficult to generalize, but in regards to hypertrophy, more IS better! On the other hand, if your goal is to maintain strength, less volume is needed. Aim for at least 30 % 1 RM with every set near failure. Some evidence suggests that BFR can be optimized by exercising the same muscle group 1 or even 2 times a day in periods of 3 weeks.

Considering these principles for BFR, bodyweight squats is insufficient for most people, but can easily be progressed by means of:

External resistance with an elastic band ➡️ Unilateral like Bulgarian split squat ➡️ Higher relative pressure (mmHg).

For regression of push-ups, just elevate the hands relative to the feet as displayed.

Please also remember, that all exercise is better than no exercise! And BFR is Better For Results – when load is low!

This research is particularly relevant for Blood Flow Restriction (BFR) training and exercise. But the utility of the present research is beyond Fit Cuffs product selection, as this will have universal implications for osciliatory/ oscillometric blood pressure measurements for assessment of LOP, a potential valid alternative to hand-held dopplers.

We find this method to determine LOP highly interesting, as this is more assessable compared to the doppler-method, which is relevant for about everyone into BFR.

We truly appreciate everyone’s efforts and commitments to test our new Bluetooth Device. Without your practical and academic expertise this was not possible. This is greatly appreciated and we look forward to continuing our collaboration.

Especially thanks to Okan KAMİŞ & Mahdy El-Zein for the dedication that goes into this study:

Okan KAMİŞ, MSc, Lecturer, PhD Student, Faculty of Sports Sciences, Gazi University/Ankara,Turkey.
& Mahdy El-Zein, PT, MPT Student, Faculty of Public Health, Lebanese

February 23, 2020

It seems that passive BFR (BFR without exercise), has the potential to attenuate muscle loss during periods of immobilization (2). Though, for obvious reasons this application is inferior to active modalities.

For the initial stage post-surgery or in some chronic cases, joint swelling and symptoms can be triggered by even low load resistance training. This is especially in such cases that BFR cycling can be the key to regain muscle and mass strength (3).

In the BFR literature, it seems that both continues or interval training can be utilized for hypertrophy and muscle strength (4). But as the muscle specific adaptations seems superior for conventional high intensity training (HIIT) vs. continues, it seems coherent that this is also the case for BFR training. Thus, a single study actually discover the opposite trend (4).

The central paradigm of this ladder-principle, is the reverse nature of progression or regression for early stage rehab vs. prehab, respectively:

Conventional high-load resistance training →

⬆️ Low-Load resistance BFR training, moderate pressure (mmHg) →
⬆️ Very low-load resistance BFR training, high pressure (mmHg) →
⬆️ High intensity interval BFR Cycling →
⬆️ Continuous cardiovascular BFR i.e. steady state walking or cycling →
⬆️ Passive BFR

As described above, we propose that this extended progressive model should be reversed for the general population. That is, if you are able to lift heavy without any pain, conventional exercise should be first line healthcare, but if this is not applicable regress one step, etc.

In the video, a woman with a total knee replacement is training with high intensity intervals for late stage rehab, as in her case, even very low-load training is associated with excessive joint swelling.

Source:

(1) Loenneke et al. (2012) Blood flow restriction: An evidence based progressive model (Review).

(2) Barbalho et al. (2019) Addition of blood flow restriction to passive mobilization reduces the rate of muscle wasting in elderly patients in the intensive care unit- a within-patient randomized trial.

(3) Slysz et al. (2016) The efficacy of blood flow restricted exercise: A systematic review & meta-analysis.

(4) Oliveira et al. (2016) Short-term low-intensity blood flow restricted interval training improves both aerobic fitness and muscle strength.

The default recommendation for upper body and lower body BFR exercise is to use at least 40% LOP and 50% LOP, respectively, for non-failure BFR protocols like the standard four sets of 30-15-15-15 reps. But because both BFR Stimuli and load contribute to the fatigue caused by BFR exercise, we must also consider relative load for a final recommendation (1,2):

Because higher blood flow restriction pressures are likely to be beneficial for muscle growth when very low loads are used (1), it turns out that simple bodyweight-based BFR exercises such as squats and lunges are sufficient to increase muscle mass and strength in active adults (3).

For practical applications, if the relative load is very low (10-15% 1RM), then it can be compensated by higher reps and using a higher pressure (1), as about 70% and 80% for upper and lower body, respectively. This is especially relevant for well-trained people who do not have the opportunity to hit the gym, because of travel, lack of time or simply just for convenience.

Reversely, the current data suggest little or no differences in muscle growth, muscle size or endurance in response to 40% vs. 90% LOP when using higher relative load (30% 1RM). But the 90% LOP condition produced higher ratings of perceived discomfort (2), which is counter productive for adherence to about any exercise program.

But as the data also suggests, that the combined effect of higher loads and higher pressures means less exercise volume, this might have some relevance. So, if you can withstand the high discomfort by combining higher pressure and load, aim for about four set of about 30-10-10-10 reps (2).

As displayed in the video, a higher relative load (30-50% 1RM) is being used, but as a tradeoff, use less pressure (40% LOP) and maybe slightly longer inter-set rest (45s -1 min).

Source:

(1) Dankel et al. (2017) Are Higher Blood Flow Restriction Pressures More Beneficial When Lower Loads Are Used?

(2) Counts et al. (2016) Influence of relative blood flow restriction pressure on muscle activation and muscle adaptation.

(3) Kang et al. (2015) The effects of bodyweight-based exercise with blood flow restriction on isokinetic knee muscular function and thigh circumference in college students.

A newly published review on BFR and discomfort concludes that particularly for the upper body, narrower cuffs seems to be favorable as wider cuffs seems to increase discomfort during exercise (1). For the general public and healthcare this is of huge importance as the adherence to exercise or rehabilitation is imperative for effect regardless of goal setting.

Though, there is a range of tradeoffs or pros and cons to consider when choosing the right cuff width:

Narrow cuffs require higher absolute pressures to elicit the same relative pressure which can inhibit estimation of LOP and increase compression into the underlying tissue (2). The relative fluctuation of pressure and mechanical compression during muscle contractions is also larger.

On the other hand, narrow cuffs allow for more freedom of movement and even though the localized pressure is higher, a smaller area of the muscle is affected by this which seems of importance (1).

During the prolonged development of Fit Cuffs into it’s current form, the cuff material has also been discovered as extremely important especially for the upper body, Thus, the research has yet to confirm this point (3).

Since muscle contractions in the upper arm expands the girth relatively more compared to the upper leg, a stiff material is not alone discomfortable, but also hinders muscle contractions and in extreme cases can lead to tissue damage (1,2).

For a visualization of the inherent properties of different cuff material, see the figure from Mcewen & Casey (cuff type B vs C). This is also why Fit Cuffs is designed with differentiated properties with the upper body cuffs being more pliable.

Source:

(1) Spitz et al. (2020) Blood Flow Restricted Exercise and Discomfort A Review.

(2) Mcewen & Casey (2009) Measurement of hazardous pressure levels and gradients produced on human limbs by non-pneumatic tourniquets.

(3) Buckner et al. (2016) Influence of cuff material on blood flow restriction stimulus in the upper body.

When assessing BP you should always use a calibrated cuff in terms of the width of the cuff relative to the circumference of the limb you are assessing. The recommended cuff width is 0.4 relative to the circumference of the limb (3).

That is why a standard BP cuff is about 14 cm wide, which is a calibrated cuff size relative to the upper arm for most adults. But if you are assessing BP on obese or bodybuilders, this would not be a valid measurement of BP, as in these cases you would need a wider cuff to avoid overestimating BP (4). The same principles apply for a very small upper arm, as you need to use a narrow cuff (4).

So even though measurement of BP is only valid when using a calibrated cuff, the amount of pressure to completely stop arterial blood flow is both valid and reliable (5).

Practical Application – how to find LOP via Bluetooth:

Connect the Unit with your phone via standard bluetooth tech.

Connect the Bluetooth Unit with the hose of the Fit Manometer, then connect the unit to the cuff.

Completely rest the corresponding limb and follow the displayed guide provided by the app.

After appropriate measurement you will find SYS (SBP) on the top left corner on the phone. This is the Limb Occlusion Pressure (LOP) for that limb in that particular position, just as the standard but prolonged method with a hand held doppler.

When preparing for exercise just detach the Bluetooth Unit and set the pressure relative to SYS (40-80%).

Research has shown that this method (oscillatory blood pressure measurement), is more precise compared to a hand held doppler ultrasound, relative to the golden standard i.e. invasive methods (5).

Our preliminary testing is showing a very good inter-rater reliability, by comparing this bluetooth device vs. LOP by hand held doppler, as a variance of only 3-6%.

Source:

(1) Babbs (2012) Oscillometric measurement of systolic and diastolic blood pressures validated in a physiologic mathematical model.
(2) Berger et al. (2001) How Does It Work? – Oscillatory blood pressure monitoring devices.
(3) Beevers et al. (2001) ABC of hypertension Blood pressure measurement Part I -Sphygmomanometry: factors common to all techniques. Clinical review.
(4) Croft & Cruickshank (1990) Blood pressure measurement in adults: large cuffs for all?
(5) Jordanow et al. (2018) Comparison of oscillometric, Doppler and invasive blood pressure measurement in anesthetized goat.
(6) Zachary et al. (2020) Limb Occlusion Pressure: A Method to Assess Changes in Systolic Blood Pressure.

First of all, there is no such thing as an optimal rehab regime, and secondly, optimal rehab must be individualized. No people are alike, the same goes for any injury, because of this an individual approach is always recommended.

Individual components such as daily activity, type of surgery, pain levels and not at least personal preference of exercises should be considered. But for most people or relevant stakeholders, the expected time to return to sport or daily activity is of high priority.

Especially in cases of load or weight bearing restrictions, the application of BFR is an effective way to attenuate muscle loss as a supplement to other rehab modalities, as this can accelerate muscle strength and function much earlier compared to a conventional rehab protocols. Though, as always consider the healing properties of subsequent tissues.

E.g. post ACL reconstruction, muscle strength and function can conceivably be reestablished at a higher rate than the remodelling properties of the transplanted tendon. But by following the guidelines and time for return to play, the inclusion of BFR can lead to greater functional symmetry (1) and probably higher estimated pre-injury capacity (2), which are both proven to lower the risk of reinjury.

In rare occasions there can be adverse side effects or other contra indications that inhibits the use of BFR, especially for early stage rehab (0-2 weeks post op.). That is why it is recommended to consult the surgeon before implementation of early stage BFR and always be aware of any additional swelling compared to other conventional exercises.

Conclusion: BFR should be used on the basis of an individual preference with consideration of physical components, such as healing properties of surrounding tissues and potential contra indications.

Video material from @cjmcfarland17

Source:

(1) Kilgas et al (2019) -Exercise with Blood Flow Restriction to Improve Quadriceps Function Long After ACL Reconstruction.

(2) Wellsandt et al. (2017) Limb Symmetry Indexes Can Overestimate Knee Function After ACL Injury.