Blood Flow Restriction (BFR) Training: Does Exercise Selection Matter?

Be Sure to Check With a Qualified Healthcare Practitioner Before Trying Any Training Tool, Including BFR.

Blood flow restriction (BFR) training is a concept that has been researched for a quite some time and appears to be a safe and effective tool for the training of strength and physique athletes as well as the rehabilitation of musculoskeletal pathologies in physical therapy.  Due to the increased popularity of BFR training, more and more questions have arisen about the optimization of its implementation (say that 5 times fast).  Today, we’re talking about why exercise selection may be key and, depending on the exercise, can either enhance or hinder the effects of BFR.  Let’s get to it!

At this point, you’ve likely crossed paths with BFR training.  You’ve sought out reputable resources, dove into some research, and maybe even read my article here, watched my extensive research review video here, and read Alberto’s stellar blog post here. You may have even implemented BFR into your own program.  You have all your boxes checked: wrap proximally…check. Use about a “7/10 tightness”…check. 3-5 sets with rep ranges on the higher side…check.  Have an understanding of the mechanism by which BFR works…check.  Defer your betting rights of the current hand and nonchalantly knock your knuckles on the table?…check.

Before we get started, it’s important to understand how blood flows through the body.  This quick review of the circulatory system also appears in my previously mentioned article, so if you’ve read it already, feel free to skip over the bracketed section below.

[The system is a cycle with the heart at the core. Oxygenated blood enters the heart and is pumped (with great force) into the arteries.  The arteries carry oxygen rich blood to all the tissues of the body, including muscle.  For simplicity, let’s use the biceps as an example.  As the arteries approach the muscle, they become thinner and thinner until they become so thin that the nutrients and oxygen diffuse across its walls and into the tissue.  These super thin blood vessels are called capillaries.   After the blood “drops off” its oxygen and nutrients, it is picked up by more capillaries, which feed into larger blood vessels called veins. The veins passively carry the deoxygenated blood back to the heart.  Once back at the heart, the deoxygenated blood gets sent to the lungs to get re-oxygenated, sent back to the heart, and is pumped back into the arteries to start the cycle all over again. 

So the force from the initial pump from the heart is enough to send the blood from the heart, through the arteries, through the capillaries, into the veins, and back to the heart all while fighting gravity, plaque build up, etc. (pretty amazing huh?).  So it is easy to see that the velocity of blood flow is MUCH greater in the arteries than it is in the veins.  Think of pushing a toy car across the floor.  The initial push (the heartbeat) gives the car a decent amount of velocity, however as the car travels further and further away, its velocity lessens.

What is BFR Training?

The goal of BFR training, or occlusion training, is to maintain arterial inflow of blood while occluding venous return during exercise.  We want to get that nutrient, hormone, and oxygen-rich blood to the muscle, while delaying its escape. This is accomplished by the application of a blood pressure cuff, knee wrap, or anything that can be tightly secured around the most proximal (closest to the midline of the body) part of a limb.  If we use the arm muscles as an example, the wrap would be tightly secured around the upper arm, as close to the shoulder as possible, causing the blood to pool in the arms.  It is thought to have a positive effect on hypertrophy while using much lighter loads than conventional weight training.

How is it possible to restrict venous return without restricting arterial flow?  Let’s think back to our circulatory system review.  The blood in arteries has a much higher velocity and propulsion force than the veins, so in order to occlude arterial blood flow, a much higher pressure is needed.  It is easier and requires less pressure to restrict blood flow in the veins because at that point, the flow of blood is not as forceful.  Think of in the movies when someone gets an injury and the blood is squirting and pulsing out.  The movie is depicting an arterial injury because of the high velocity of blood. If a vein were injured, the blood would just ooze out.]

The Silent Helper

Much has been studied and written about the effectiveness of BFR training, however there is something that, to my knowledge, has not been studied much and that I believe plays a key role in the efficacy of BFR training.  It has to do with a familiar silent force that we all know and love…gravity.

As previously mentioned, the goal of BFR training is to slow down venous return of blood to the heart and cause blood and metabolites to pool in our working muscles.  Gravity has one job and one job only…pull things downward, including blood flow.  This can help or hinder the restriction of blood, so work withit not againstit!  For example, when performing a traditional biceps curl with BFR, the cuff andgravity are working togetherto cause the blood to pool in the arms.  The cuff prevents blood from leaving as gravity pulls it downward. Together, the BFR cuff and gravity offer a 1-2 punch that restricts venous return and causes the blood to pool in the arms.

To show gravity’s impact on blood flow, try this test right now as you read this. Let your arms hang down at your sides. Open and close your hand and flex and extend your wrist a few times for about 15-20 seconds.  Take a look at your forearms.  See any veins popping?  Most likely, the answer is yes.  Now raise your arms over your head.  What do you notice immediately?  No more bulging veins!  Why? Because you didn’t have your apple cider vinegar, pre workout nitric oxide booster, and raspberry ketones yet today? No.  “Holding” water under the skin perhaps?  Nope.  It’s just gravity pulling the blood from your arms back to the heart.

So my suggestion is that if you’re going to use BFR, use it on exercises that place the targeted muscle in a dependent position (hanging downward).  That will allow gravity to work with you rather than against you and help keep that blood in the targeted muscle.

Keeping The Training Goal In Mind Will Help With Exercise Selection

Three primary factors of resistance training that result in muscle hypertrophy are mechanical tension(lifting heavy weight and accumulating volume), metabolic stress(the pump and burn), andmuscle damage(micro-tears in muscle fibers)^1,2. Progressive overload and volume accumulation are the driving forces behind these factors.  Of the proposed mechanisms of muscle hypertrophy, BFR, in general, taps into metabolic stress.  Training to maximize metabolic stress is different than training to accumulate maximum volume, where:

Volume = Reps x Sets x Load (weight)

If maximum volume is the goal, BFR may not be the best tool because it will cause your muscles to fatigue prematurely, decrease muscle performance, and increase “the burn.”  Good for metabolic stress, bad for overall volume.  That’s why it’s important to keep the goal in mind and train with a purpose.

I wouldn’t recommend using BFR with big compound movements like squats, deadlifts, and bench/overhead presses.  These exercises are highly complex and require every muscle involved to be firing on all cylinders.  BFR will cause certain muscles to fatigue quicker than others, which can be detrimental and even dangerous when performing a movement like a loaded squat. Using BFR during big compound lifts will result in premature fatigue of the arms and legs with minimal stress put on the pecs, lats, glutes, etc.  “I’d like to find a way to limit glute activation during a squat and would absolutely love to find a way to feel a bench press less in my chest and more in my arms…” said no one ever.  I am not saying BFR cannot be used with big compound movements.  Just be aware that your mechanics will likely be impacted and the weight, reps, etc. may have to be adjusted accordingly.

As mentioned in my previous article and video, as well as Alberto’s blog post, the goal of BFR is to cause the blood to pool in the muscles and veins downstream from the cuff.  So if you place the wrap on the upper arm, the targeted muscles are everything from the cuff down to the fingers.  If you place the wrap on the upper thigh, the targeted muscles are everything from the cuff to the toes.  Being that blood flow restriction is limited to the limbs, muscles of the trunk such as the pecs, lats, traps, rhomboids, shoulders, glutes, and abs cannot be occluded, as they are located proximally, or “upstream,” to where the cuff is applied.  That being said, studies have shown hypertrophic changes in the trunk muscles when restricting blood in the limbs, however further research is required before the efficacy of BFR training for increasing the size and strength of the trunk muscles can be established³.

Future Research

To my knowledge, there hasn’t been much research on exercise selection and BFR training.  If you’ve stumbled on some of the BFR training research, you may be familiar with the studies showing hypertrophy of the leg muscles after low intensity cardio (walking on a treadmill) with BFR applied.  Using treadmill walking and something like a stationary bike as examples, the targeted muscles are, by nature of the exercise, in a constant dependent position.  I’d like to see a comparison of traditional stationary bike riding with the legs in their normal dependent position with stationary bike riding in some sort of upside down or inverted position.  The legs are no longer in a dependent position in this hypothetical inverted position.  This would allow gravity to assist in the rapid removal of blood and metabolites from the targeted muscles.

A similar comparison would be that of a traditional biceps curl or spider curl, where the arms are in a dependent position, with something like a high cable curl where the arms are elevated.  I would not be surprised if the high cable curl showed less of a benefit than the traditional or spider curl variations.  Again, that’s just my guess.  Take a look at other BFR studies.  Are the targeted muscles in a dependent position or are they elevated?

Again, and just to be clear, to my knowledge, there hasn’t been much research on exercise selection for BFR training, but I’m sure it is on the horizon!  That’s the beauty of science.  As new concepts and ideas are born and old problems are solved, new questions and new problems prompting further study arise!

If my speculations are correct, here is a list of some exercises that may work well with BFR and other exercises that maynot work well with BFR.   This list is far from completebut if you use the dependent position rule as a guide, you will be able to use this concept with any exercise!

The Good

Spider Curl

Preacher Curl

Incline Dumbbell Curl

Standing Barbell/Dumbbell Curl variations

Triceps Pressdown

Grip/Forearm Work*

Leg Extension

Leg Curl

Calf Raise (standing or seated)*

*Remember to still wrap the cuff on the upper arm or upper leg even when targeting the forearms and calves.

The Not So Good

Squats

Deadlift

Bench Press

Overhead Press

Abdominal Work

Pull-ups

Pull-downs

Rows

High Cable Curl

Overhead Triceps Extension

Lying Triceps Extension (skull crusher)

Leg Press (45 degree or vertical set-up)

To Wrap It Up (Pun Intended)

Blood flow restriction training can be a great tool in your toolbox, however keep in mind that it’s not whatwe do that matters, it’s howand whywe do it.  By understanding the mechanism by which BFR training works, it is reasonable to think that exercise selection mayhave the ability to enhance or lessen our results.  Try sticking to exercises that place the arms and legs in a dependent position to maximize the effects of BFR training.  Keep your eyes open for new studies on this topic and if/when you find some, be sure to leave a comment and let me know!

References

¹Schoenfeld BJ. Potential mechanisms for a role of metabolic stress in hypertrophic adaptations to resistance training. Sports Med 43: 179–194, 2013. http://www.lookgreatnaked.com/articles/potential_mechanisms_for_%20a_role_of_metabolic_stress_in_hypertrophic_adaptations_to_resistance_training.pdf.

² Schoenfeld BJ. The mechanisms of muscle hypertrophy and their application to resistance training. J Strength Cond Res 24: 2857–2872, 2010. http://www.ucam.edu/sites/default/files/Oct_13/mechanisms_of_muscle_hypertrophy.pdf.

³ Yasuda, Tomohiro & Ogasawara, Riki & Sakamaki-Sunaga, Mikako & Bemben, Michael & Abe, Takashi. (2011). Relationship between limb and trunk muscle hypertrophy following high-intensity resistance training and blood flow-restricted low-intensity resistance training. Clinical physiology and functional imaging. 31. 347-51. 10.1111/j.1475-097X.2011.01022.x.

Further Reading

If you’re looking for more information in BFR training, here are some great places to start.  In addition to these references, please be sure to check out the work of Jeremy Loenneke as well as StrengthandConditioningResearch.com

Abe T, Kearns C, and Sato Y. (2006) Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training. J Appl Physiol100: 1460–1466.

Boucourt, B., Bouhaddi, M., Mourot, L., Tordi, N., & Ménétrier, A. (2014). Changes in tissue oxygen saturation with calf compression sleeves-before, during and after a cycling exercise. The Journal of sports medicine and physical fitness. 55(12):1497-501

Egerton, T., Beardsley, C. Blood Flow Restriction Training. Strength and Conditioning Research.Retrieved on 7/21/16 from https://www.strengthandconditioningresearch.com/blood-flow-restriction-training-bfr

Kubota, A., Sakuraba, K., Sawaki, K., Sumide, T. & Tumara, Y. (2008). Prevention of disuse muscular weakness by restriction of blood flow. Medicine and Science in Sports and Exercise, 40(3), 529-34. [

Loenneke JP and Pujol TJ. (2009).  The Use of Occlusion Training to Produce Muscle Hypertrophy.  Strength & Conditioning Journal. 31(3): 77-84.

Menetrier, A., Mourot, L., Bouhaddi, M., Regnard, J., & Tordi, N. (2011). Compression sleeves increase tissue oxygen saturation but not running performance. Int J Sports Med, 32(11), 864-868.

Takarada Y, Takazawa H, and Ishii N. (2000). Application of vascular occlusion diminish disuse atrophy of knee extensor muscles. Med Sci Sports Exerc32: 2035–2039.

Nicholas M. Licameli, PT, DPT

Doctor of Physical Therapy / Pro Natural Bodybuilder

Every single thing he does, Nick believes in giving himself to others in an attempt to make the world a happier, healthier, and more loving place. He wants to give people the power to change their lives. Bodybuilding and physical therapy just act as mediums for carrying out that cause. Love. Passion. Respect. Humility.   Never an expert. Always a student. Love your journey.

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