If you’re in weight-lifting or occupational therapy circles, then chances are you’ve heard about blood flow restriction training. Because of what it entails, BFR is also known as occlusion training.
In this article, we will give you a drill-down of what blood flow restriction training involves – specifically, the science of it. You will be able to discern what steps to take if it is something that may interest you, or that can address any relevant problems you have.
Defining Blood Flow Restriction Training
If you are in the fore-mentioned circles – occupational therapy, general fitness, rehabilitation etc. – then you have likely encountered discussions involving blood flow restriction training. The recent prevalence of professional athletes touting its benefits on television has caused search results to explode.
Although this news might be enticing, it’s important to know that BFR isn’t a new phenomenon by any means. Official medical research involving it is well over two decades old and counting – were talking about-reviewed medical trials that have returned great results.
What, exactly, is BFR? Basically, if you possess a strap or a cuff which can be tightly wound, then you can try it with a minimum of online research to guide you as to the proper technique. You place a strap around the appendage in question to restrict the flow of blood; take care not to completely cut off the flow of blood however. Usually, the names used are the armor and the land since these are the ones most prevalent in athletic activities.
It turns out that when you restrict blood flow, this allows you to work out your arm or leg at a lower intensity; your body treats the workout as if you’re working out at high-intensity. Basically, you’re able to derive the high quality benefits of high-intensity exercise with low intensity effort.
Perhaps this sounds too good to be true – after all, there are literally dozens of fly-by-night exercise products which claim to give you stellar results with minimal effort. All it takes is an especially late-night infomercial for you to encounter electric shirts that you can wear which will purportedly give you six-pack abdominals. These come and go without any medical backing or research to show for it.
Blood flow restriction training, on the other hand, has dozens of years of such evidence. When combined with the centuries-worth of data on strength training and exercise benefits, BFR stands head and shoulders above the other fitness claims.
If you’re anything like us however, it’s going to take more than a little bit of touting to convince you as to the benefits of blood flow restriction training. We aim to give you a comprehensive understanding, and that begins with first knowing the mechanism behind muscle strengthening.
Muscle Strengthening Mechanism
The very basics of muscle strengthening are fairly straightforward: you effectively tear them down, in order to build them back up stronger. Not only does this get your muscles stronger, it also get them bigger – as long as you are eating or supplementing your diet with enough protein with which to fuel the building process.
The purpose of resistance training is to put your muscles through enough of a trial to send signals to your brain that you’re going to need more power for the load next training session. This adaptation takes place through mechanical first, neural second, and the resulting metabolic mechanisms last to complete the circuit.
A detailed scientific explanation is not really necessary – especially since it could take up a college textbook. For you to completely grasp how and why blood flow restriction training works so well, all you need to know are the basics of muscle dynamics.
Inside of your body, your cells are instrumental in the release of hormones such as testosterone, which is tailor-made to respond to load and volume in your journey towards bigger and stronger muscles. It turns out that when you are engaging in multi–joint workouts with heavy weights, your testosterone will increase dramatically to meet the demand for more power. Often concomitantly, if you are engaged in multi-joint workouts at high-volume (that is to say, many repetitions), your body will respond by releasing growth hormone.
Therefore, you can see that if you engage in high intensity exercises for very short periods of time, then you will not see an infusion of growth hormone. On the other hand, if you engage in moderate intensity exercises at high-volume/many reps, your body will release growth hormone to help you meet the demand.
There are several cellular structures and pathways which are instrumental in the above activities.Let’s get into a tiny bit of the science behind this – the following are activated to help you accomplish and benefit from high-load (heavy weights basically) training:
- Vascular endothelial growth factor (VEGF)
- Insulin-related growth factors (IGF’s)
- mTORC1 pathway
You don’t have to workout very long to benefit from the above being activated when you use high loads in your workouts. In some for this section, these are absolutely essential if you want your muscles to grow large and strong.
Blood Flow Restriction Training: The Basics
There are several ways to ascertain the effectiveness of blood flow restriction training. The first way that will analyze pertains to muscle annotations based on the use of anabolic signaling pathways, muscle activation and muscle fatigue. When studies based on this are undergone, they are compared to a control group in which the participants engage in the same exercises without the benefits of BFR.
Based on the above, analyses seem to show that when you have limited arterial blood flow, this induces an accumulation of certain metabolites that form exclusively/primarily in a hypoxic environment. Therefore, the indirect effect is the muscle activation, fatigue and preferential anabolic pathways mentioned earlier.
From our earlier explanation of what is required to make muscles bigger and stronger (volume and high loads), we can see how BFR can be useful to people nursing chronic injuries, or getting back to working out after a surgery – basically, whatever your situation is which actively prohibits the use of high loads.
As you can see from the scientific results, blood flow restriction actually mimics high load activities at moderate volume – precisely what’s necessary to make muscles bigger and stronger. Meanwhile, by using the strap to limit blood flow, those preferential metabolites develop in the hypoxic environment, such that low load exercise routines can confer to your muscles the same benefits as high load exercises without the strap.
BFR can be of great use even in extreme situations, such as when muscle atrophy may set in due to severe injury or incapacitation. BFR training can even be very useful in situations where no load is used, in order to maintain the muscle protein synthesis necessary to staving off atrophy. In fact, by activating the necessary pathways, BFR no-load training can actually activate muscle protein synthesis.
Due to the hypoxia created by the blood flow restriction training apparatus, your body effectively recruits more muscles to the area while simultaneously getting tired faster – despite the much lower loads. This simultaneous firing of muscle fibers induces hypertrophy, such that you can even simulate the gym-favorite muscle pump due to the swelling induced. Once the constriction is abandoned, the arterial pathways will experience an inrush of muscle building ingredients to the site.
The Utility of BFR in Physical Therapy
From the above, we can see how proper blood flow restriction can be extremely useful in occupational therapy and physical therapy. One of the chief drawbacks of recuperating a muscle is the tendency for weakness and outright muscle atrophy to set in. Although in the very early stages of recuperation, electrical stimulation, isometrics, biofeedback and others are useful; once the tissue starts to heal back these are less effective.
The subject is certainly not ready to start placing the affected muscles under heavy load soon after the tissues heal sufficiently. However, BFR is a tactical measure that does not jeopardize re-damaging the healing tissue. At the same time, you can benefit from the ability to start regaining strength early in the recovery process – as long as you use BFR of course.
It is generally accepted that in order to benefit from high load resistance training, you should be employing weights for repetitions that are 60% of your one-rep max for a minimum of 8 reps and a maximum of 12 reps. When undergoing physical therapy for muscle recovery, you can stave off muscle atrophy by training with loads averaging about 25% of your one-rep max with 15-30 reps per set.
The Real Question: Is BFR Training Effective Beyond the Theoretical?
The answer to this is a resounding “Yes!” There has been terms of research explicitly stating just how effective blood flow resistance training has been on a myriad of subjects. The specific results run the gamut:
- BFR has improved aerobic capacity
- BFR training has significantly attenuated muscle atrophy
- BFR training has elevated muscular strength
- BFR training has activated muscle hypertrophy
Indeed, there has also been diagnosis-specific results when blood flow restriction training has been implemented in physical therapy trials and facilities. Let’s take a look at a handful of the outcomes stemming from the specific diagnoses as listed below.
Geriatric BFR – Mature Patient Population
It turns out that blood flow restriction training techniques show very promising results when used within the geriatric population. In particular, aged patients have benefited from noticeable/significant pain relief.
Due to the age of this group, the necessary precautions must first be taken. The studies conducted did precisely that (in terms of preparation for exercise), and they noticed significantly-increased muscular strength and size in the older patients after 6 weeks of BFR training (in one study in particular), when compared to a control group of patients who didn’t use BFR training.
Post-ACL Reconstruction Surgery – BFR Training Results
An uncomfortable number of professional athletes can attest to the significant loss in quadriceps strength post-ACL reconstruction surgery. The studies we looked at involved regular athletes who’d undergone various similar knee surgeries with the same loss in quadriceps strength. A multitude of such studies proved that blood flow restriction training was very effective in helping to restore strength after the significant losses of muscular strength that are usually endemic to ACL reconstruction. Additionally, there was noticeable while hypertrophy (increase in muscle size) in the same muscles.
Keep in mind that further studies are being funded even as you read this, but for the meantime you can rest assured that BFR training for the specific diagnosis of ACL reconstruction surgery confers the listed benefits above.
Blood Flow Restriction Training After Muscle Immobilization
The chief muscle-related problem with extended immobilization of a particular limb or appendage is muscle atrophy. If you’ve been involved with occupational therapy or physical therapy in any way, then you have doubtless seen many of the detrimental effects that this has.
Blood flow restriction training has definitely conferred benefits in these cases; just think about it – usually, such patients are rooted to a hospital bed and definitely cannot undertake resistance training with heavy loads. The significantly lower loads with the use of BFR has produced some seriously good results.
Blood Flow Restriction Training Used on Knee Pain
Out of all the specific cases on this list, the most popular one that we encountered was how BFR works for knee pain relief. Knee pain is probably the chief endurance for a variety of leg-related workouts – from power walking, jogging, running, jumping to engaging in weightlifting. Clearly, since knee pain is not often experienced while sitting or laying down, it is the load-bearing aspect of these activities that presents a problem.
Since the very definition of BFR training is the use of low loads, this is proved to be quite useful in reducing the need for pain associated with knee osteoarthritis, patellofemoral pain and ACL reconstruction surgery.
BFR Training Primer: Safety first
Because of the wealth of information weaned from the many varied trials using BFR, we can conclusively say that it is generally safe. Obviously, if it is misused – just like anything – it can produce negative results.
The range of musculoskeletal issues that have been successfully addressed by blood flow restriction training is unquestionable. For every single one of the studies, there is yet to be an adverse event reported. With that said, there are certain side effects which are consistently short-lived and are generally regarded as part-and-parcel of the treatment process itself. Some of these include discomfort, skin abrasions, bruising and numbness, delayed muscle soreness and petechial hemorrhage.
With all that said, a medical review has returned very positive results with respect to the risk of blood clots with the usage of BFR training therapy: the risk is virtually negligible. Experts in BFR training recommend that you wait a minimum of two weeks post surgery in the affected region before you begin blood flow restriction training; this wait-period. Dramatically reduces the risk of any address events.
Are There Any Contraindications With BFR Therapy?
There are, indeed, a few contraindications associated with blood flow restriction training – however, all of these are associated with patients who possess cardiac issues or other vascular insufficiencies.
As you might have surmised, the restrictive techniques involved with BFR training can lead to an elevated risk of cardiac stress as the blood vessels have to work harder to shuttle arterial blood throughout the body – in particular, to the muscle tissues.
Some of the other conditions conducive to vascular insufficiencies include diabetics, those with a prior history of DVT or stroke, blood clot disorders, active infections and cardiac disease, hypertension or even pregnancy. All of these, including varicose veins of sufficient severity, are notable contraindications to BFR training.
This is why, as a matter of course, it is advisable to consult with a primary care doctor in order to help ascertain the appropriateness of BFR training for a particular patient. The importance of clinical reasoning cannot be understated when making a decision regarding the appropriateness of BFR therapy for a given situation.
Who Is Qualified To Provide BFR Training?
First of all, the general principles of BFR training are well within the scope of expertise of athletic trainers, physical therapists and occupational therapists. As a result, there’s no extra certification required to legally practice it (generally). With that said, perform due diligence in certifying this with the laws of the state.