Maybe you’ve seen that one bodybuilder in your gym always crushing workouts with a cuff on their arm while they do preacher curls. Or maybe you’ve heard the rumor that blood flow restriction (BFR) training can help make your muscles bigger without the need to dramatically increase the weight you’re lifting. Whatever the case, you’re trying to figure out if BFR is worth your time — or if it’s just another gimmicky fitness fad.
Blood flow restriction training, also called occlusion training, involves placing an inflatable cuff on the limb you’re exercising. The idea is to restrict some — but not all — blood flow to your muscle while you’re lifting weights. This restriction is often touted as a way to make your muscles grow bigger, faster. This article will explore the science behind BFR so you can figure out whether this kind of specialized training is right for you and your goals.
What is Blood Flow Restriction Training?
To train with blood flow restriction, you’ll wear a cuff or tourniquet system specially made for this kind of training. Many lifters also use a band that their training partner may help them tighten. You’ll place it at the proximal end of whichever extremity you’re focusing on. Proximal (as opposed to distal) means the part of your limb closest to your body’s midline or trunk. In short — you want the cuff on the part of your extremity that’s closest to your heart.
What does this cuff placement do? It restricts some, but not all, blood flow. When you apply a firm pressure with the cuff or band — without it being tight enough to cause any pain — the idea is that you’re only restricting certain blood vessels. Basically, your arteries can still send oxygen-rich blood to your muscles during BFR training — but your venous, oxygen-depleted blood flow is restricted. In other words, BFR is about preventing blood from leaving the muscle rather than preventing blood from getting in.
There are multiple natural responses the body uses to compensate for muscle damage. But one of the main responses linked to increased muscle repair and size is called muscle protein synthesis. This is the body’s way of naturally repairing itself through the use of multiple anabolic mechanisms. With BFR training, you place additional stress on your muscle that regular training can’t induce (like venous occlusion and depleted oxygen). In response, your body may increase muscle protein synthesis. This is the theory behind using BFR to increase muscle hypertrophy.
Potential Benefits of Blood Flow Restriction Training
There’s more than one reason that a lot of people turn to BFR training when they want to enhance their gains. This method can help you get bigger muscles while working with very light weights, which is potentially a lot easier on your joints than going hard every day.
The main reason many athletes use BFR training is to spur on muscle growth. Research suggests that BFR can significantly increase muscle size compared to traditional resistance training. (1)(2) Studies have shown that athletes using BFR at 30 percent of their one-rep max made more strength and muscle thickness gains compared to participants who trained traditionally at 80 percent of their one-rep max. (1) So if you’re looking to increase muscle size with light weights, BFR might be a huge help.
Big Benefits, Lighter Loads
You don’t have to go hard for BFR to be effective. Studies have found that activities like low-intensity lifting and even walking can increase muscle strength and size when performed with BFR. (3) Even in terms of resistance training, studies generally show big hypertrophy benefits from BFR while using loads as low as 30 to 50 percent of each lift’s one-rep max. (4)
Easier on Your Joints
Because you’ll be lifting significantly less weight while training with your blood flow restricted, the work may be easier on your joints. It takes a lot of strain for your joints to be under so much shearing pressure when you’re lifting maximally heavy weights.
Being able to give your joints a break while lifting a bit lighter may well be a welcome, lower-impact change for your joints. Sure enough, BFR paired with low-intensity training has also been used to help reduce pain and increase muscle strength from knee injuries. (5)
How Does Blood Flow Restriction Training Work?
Studies suggest that BFR helps your muscles grow because it impacts the levels of vascular shear stress and the availability of oxygen in the muscle you’re restricting. (6) In preventing oxygen-depleted blood from leaving the muscle, BFR increases the amount of oxygen-poor blood in the targeted muscle. Overall, it creates a depletion in your muscle’s needed resources, since your muscle now has to contend with a build-up of blood that needs nutrients and oxygen. This added stress then causes an increase in natural anabolic responses by your body that normal training may not produce alone.
But even though you’re manipulating your blood flow, studies suggest that this kind of training generally shouldn’t negatively impact your cardiovascular, endocrine, or musculoskeletal systems. (7) That said, other research points out that even though BFR places less stress on your joints — because you can achieve hypertrophy with less load — scientists are still unsure as to whether this method can produce long-term endothelial (blood vessel) damage. (8)
How to Do Blood Flow Restriction Training
Doing BFR properly is key to its effectiveness. The first couple of times you do it, you might want to consult with an experienced professional just to make sure your grasp of the basics is solid.
BFR Cuff Location
To put your BFR cuff or band in the right location, you always want to place it on the proximal side of your chosen limb — the part closest to your midline, or your heart.
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That means you should place the cuff above your biceps instead of at your wrist when performing barbell curls. Place the cuff on your upper thigh instead of near your ankle when you’re going for hamstring curls.
BFR Cuff Tightness
In terms of wrap tightness, studies say that you want to aim to apply moderate pressure from the cuff without any pain. (9) Aim for a seven out of 10 on the tightness scale, as long as that seven doesn’t induce any pain or numbness.(9)
BFR Load and Rep Range
Research suggests keeping intensity on the lower side and often using 30 to 50 percent of your one-rep max to stimulate BFR response. (1) Since the load is so light, set your rep range between 15 and 30 reps per set. Training with higher intensities can lead to more muscle damage, which may be counterproductive.
What to Consider Before Trying Blood Flow Restriction Training
Whenever you’re starting a new form of training that you’ve never tried before, there are some important points to consider. Here are some of the factors to take into account when you’re thinking about starting BFR training.
When you’re starting an intense training method, there’s nothing wrong with checking in with your medical provider first. That may be especially true for BFR training. Research has been unclear about whether BFR can cause endothelial damage, so you may want to consult with your doc before proceeding. (8) This may be especially true if you have a history of issues with your blood pressure or blood flow in general. If that’s the case, you’ll more than likely want to take a hard pass on this method.
Your Body’s Response
You’ve put the cuff on properly and you’re reasonably certain it’s not too tight. But if it still gives you sharp pain, or makes your limb tingly or discolored, remove it. In any of those cases, your body is telling you that you should stop immediately — just as if you experienced sharp pains during a compound lift.
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If you’ve checked in with an experienced coach to make sure everything is on right and these types of problems persist, your body might just not respond well to this type of training. And that’s okay — there are plenty of other ways to grow big muscles.
You may have no physical contraindications to trying out BFR training. But if you’re the type of human that hates getting your blood pressure taken because the sensation or idea of the cuff just plain makes you queasy, then BFR training probably isn’t for you. There’s no reason you have to adapt this particular training method if you just plain prefer not to. Grab heavier weights and keep lifting — without restricting your flow.
Who Should (And Shouldn’t) Do Blood Flow Restriction Training
First things first: if you have a history of issues with your blood pressure or blood flow generally, you’ll want to avoid this style of training. And, as with anything that involves manipulating intense training variables like this, most athletes will want to check in with their doctor before moving forward.
Although there is a lot of research to suggest that BFR training can hold an important place in your program, there aren’t set guidelines for wrapping styles, tightness, programming, and training intensities. Also, different athletes will have varied responses due to training history, body type, and muscular profiles. But in general, your level of training experience might shed some light on whether you should try BFR training.
If you’re new to strength training, you probably should stick to the basics. As you’re starting out, get your body accustomed to lifting in various rep ranges at different intensities. Think about your training in terms of progressive overload. In other words, once your body adapts to new training stimuli, change one factor at a time to increase the intensity and continue your progress.
There are plenty of training variables to progress as a beginner — volume, load, and time under tension being just a few. It’s generally best to familiarize yourself with these before diving into more complex methods like BFR training.
Experienced intermediate lifters might benefit most from BFR training. When you’re genuinely an intermediate lifter (with at least six months of continuous training under your belt), you likely have a solid muscular base to build from. You’re very familiar with the essential moves of strength training and have cycled through different training variables before.
You can still stand to grow more muscle, and you don’t need quite as much load stimulation as an advanced lifter. So, the 30 to 50 percent loads involved in BFR training will be enough to potentially yield impressive results. (1)
If you choose to, you can incorporate BFR training as an advanced lifter. Maybe you need to shake up your program for psychological or physical reasons. But advanced lifters should be aware that research suggests using lighter loads for BFR training. (1) Because of that reduced load, your muscles may not get the kind of intensity you’re looking for, even while wearing a BFR cuff.
Figuring out whether to introduce a new component into your training can be tough — especially when it’s something that requires its own special equipment, like the cuffs in BFR training. But if you’re an experienced lifter who is ready to try something new, you might want to check in with your coach or doctor about getting started with blood flow restriction training. It may be able to help grow your muscles faster than traditional training does.
- Wortman RJ, Brown SM, Savage-Elliott I, Finley ZJ, Mulcahey MK. Blood Flow Restriction Training for Athletes: A Systematic Review. Am J Sports Med. 2021 Jun;49(7):1938-1944.
- Korkmaz E, Dönmez G, Uzuner K, Babayeva N, Torgutalp ŞŞ, Özçakar L. Effects of Blood Flow Restriction Training on Muscle Strength and Architecture. J Strength Cond Res. 2020 Apr 13.
- Centner C, Wiegel P, Gollhofer A, König D. Effects of Blood Flow Restriction Training on Muscular Strength and Hypertrophy in Older Individuals: A Systematic Review and Meta-Analysis. Sports Med. 2019 Jan;49(1):95-108.
- Pearson SJ, Hussain SR. A review on the mechanisms of blood-flow restriction resistance training-induced muscle hypertrophy. Sports Med. 2015 Feb;45(2):187-200.
- Li S, Shaharudin S, Abdul Kadir MR. Effects of Blood Flow Restriction Training on Muscle Strength and Pain in Patients With Knee Injuries: A Meta-Analysis. Am J Phys Med Rehabil. 2021 Apr 1;100(4):337-344.
- Pignanelli C, Christiansen D, Burr JF. Blood flow restriction training and the high-performance athlete: science to application. J Appl Physiol (1985). 2021 Apr 1;130(4):1163-1170.
- Miller BC, Tirko AW, Shipe JM, Sumeriski OR, Moran K. The Systemic Effects of Blood Flow Restriction Training: A Systematic Review. Int J Sports Phys Ther. 2021 Aug 2;16(4):978-990.
- da Cunha Nascimento D, Schoenfeld BJ, Prestes J. Potential Implications of Blood Flow Restriction Exercise on Vascular Health: A Brief Review. Sports Med. 2020 Jan;50(1):73-81.
- Wilson JM, Lowery RP, Joy JM, Loenneke JP, Naimo MA. Practical blood flow restriction training increases acute determinants of hypertrophy without increasing indices of muscle damage. J Strength Cond Res. 2013 Nov;27(11):3068-75.
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