In this interview, Mario Novo, doctor of physical therapy, discusses the many health benefits of blood flow restriction (BFR) training. It’s a phenomenally easy way to take control of your health, especially if you’re elderly. I don’t know of any intervention that will improve your health as dramatically.
BFR training was developed by Dr. Yoshiaki Sato in Japan over 50 years ago. In Japan, BFR training is known as KAATSU, which translates into “additional pressure.” It’s a perfectly descriptive name, as the KAATSU device consists of inflatable bands that provide additional pressure on your limbs.
Sato is now 73 years old and in fantastic shape for any age. He’s a really strong testament to the fact that it works. But it’s not just for strength building. Metabolically, BFR will radically improve your health and decrease your risk for sarcopenia and most other age-related diseases.
BFR in Physical Therapy and Limb Salvage
BFR didn’t arrive in the U.S. until 2010. In the years since, it’s become increasingly popular, not only among fitness experts but also among physical therapists such as Novo. Novo is also the owner of the Lifters Clinic,1 which specializes in strength and conditioning.
“At this point, I have about 12 years of experience in the world of rehab,” Novo says. “As most people who have ever experienced rehab know, when you’re in rehab, there’s a huge recommendation, and often with very good reason, for you to use very light loads.
This could be after post-injury, post-surgery or post-fracture, when exercising with heavier weights may place healing tissue at a greater risk … In the world of physical therapy, we’ve always relied on light-load training …
The San Antonio Military Medical Center has a facility called Center for the Intrepid (CFI). In that facility was one of my mentors, Johnny Owens, who … was tasked with understanding how to operate within a department known as ‘limb salvage.’
He was in a similar environment of rehab, but his patients were in a very critical state, where if they weren’t cared for appropriately, they were going to have an amputation. He had heard about KAATSU training. He had heard about how these light loads, these low-intensity exercises, are being used to increase muscle mass.
At the time, they were having trouble with certain drugs on the market to reduce scar tissue, which would help provide a more appropriate environment for collagen, but also for muscle building because one thing we’ve discovered in this process of building bigger muscle is that it’s a pathway that is very specific, and as we get older, we really rely on exercise and nutrition to stimulate it.
Once it’s stimulated, it shuts down other pathways used for making scar tissue. One would imagine when you’re hurt, your body is going to choose a path that provides protein that is not very dynamically or calorically expensive to build; hence, scar tissue, versus building muscle, which is very expensive to build. Same with collagen to a degree.
At the time, he said, ‘You know what? People are using these bands. They’re increasing muscle size. As a result of them increasing size, they are, by definition, shutting down this scar tissue pathway. There may be a way that we can start applying this in this limb salvage department, where the biggest issue we have is scar tissue.”
Owen’s experimentation with patients at CFI confirmed BFR training helped inhibit scar tissue formation and salvage more muscle. Aside from boosting strength, BFR also helped reduce pain associated with arthritis and nerve injuries.
BFR for Post-Fracture Recovery
Around 2012 or 2013, BFR was adopted by the National Football League (NFL), where it was applied for post-anterior cruciate ligament (ACL) injury, reconstruction and repair. A couple of years after that, BFR’s benefits for bone breaks also became more widely appreciated.
“One of my first jaw-dropping experiences with [BFR] was in 2015, when a player from the New York Giants came to see me after having had about 16 weeks of a malunion to a metal device put on his tibia. He had had a fracture. They attempted to put this metal device to help prevent the fracture from increasing in size.
His body was not grafting or growing onto the metal device. The screws were loose. This obviously is a large risk to him and [caused] a lot of pain. They tried bone stimulators. They tried different drugs to help uptake bone marrow nutrition, aquatic therapy, land-based training, using something that’s called an AlterG, which looks like a treadmill, but it reduces your body weight so you can stay active at a lighter impact.
Nothing was working … At that time, I was certified underneath Johnny. I just started applying a surgical tourniquet … Applying the tourniquet reduces the amount of oxygen available for his legs to continue to keep doing exercise, which means we can take very light-load exercises and have the environment in his muscle look more like if he was doing moderate- to higher-intensity exercises.
When we perform exercise at higher intensities, we consume more oxygen to continue to fuel contraction. But at a given point, our muscles and the process of contracting and using oxygen and using adenosine triphosphate (ATP), which is an energy source we all use, will begin to produce byproducts.
End of the story is, we apply BFR for this gentleman. In four weeks, he grafts onto the piece of metal. And the doctors like this. It’s fantastic. He went back out, played for a little while. He didn’t like the metal plate being in there. They took it out. We saw him again for another four weeks, and [he had] full complete closure [of the fracture].
That kind of started this huge boom, looking at BFR for not just muscle, not just strength, but also potential benefits for post-fracture …
All the NFL, the National Basketball Association (NBA), the Major League Baseball (MLB), the National Hockey League (NHL), soccer — predominantly in the U.S. and Europe — all divisional universities and some division teams are now getting on board. They all now have BFR as a modality that’s used in physical therapy.”
BFR Is Now a Standard Rehab Modality
In 2018, the American Physical Therapy Association approved BFR as an indication for rehab, making it part of physical therapists’ scope of practice. So, it’s not an alternative medicine or an alternative modality. It’s indicated for knee pain, for example, including knee pain associated with osteoarthritis (OA).
It’s also a tool used to address osteopenia, sarcopenia, high blood pressure and diabetes. It may also be useful in the treatment of traumatic brain injury (TBI) and post-stroke. Unfortunately, it still does not have a reimbursable current procedural terminology (CPT) code (a medical code used for billing), but eventually, there will be.
How BFR Affects Your Physiology
There are two primary types of muscle fibers: Type 1, the slow, endurance-type fibers; and Type 2, the fast-twitch fibers, which are primarily anaerobic and use glucose, not oxygen. Type 2 fibers are larger than Type 1 and tend to kick in when the oxygen supply runs out and the Type 1 fibers are exhausted.
The activation of Type 2 fibers generates lactate as a metabolic byproduct. The lactate builds up because the BFR bands don’t allow the lactate to diffuse systemically. This buildup of lactate provides many of the metabolic benefits of BFR.
With age, or when you’re injured, exercising intensely enough to maintain health can be a challenge. This is where BFR shines, as the light load required doesn’t overstrain you, while still providing benefits you’d normally only see with heavier exercise loads. Novo explains:
“BFR can benefit muscle tissue by increasing the amount of muscle hypertrophy. That means, at a very fundamental level, we’re increasing the health of the muscle. We’re helping the muscle to have to rely on less insulin, to allow for energy — carbohydrate and sugar — to make its way into the cell.
That can provide other benefits, such as reduced blood glucose levels and reduced blood pressure. Obviously, less reliance on insulin also means less inflammation generally in the body. Other benefits seen at the level of the muscle have to do with the muscle and its ability to become more resistant to forces being placed on it.
As the muscle gets bigger, it doesn’t only get bigger in the proteins that contract, but it also gets bigger in the proteins that just provide structural support for the muscle, which means your muscle gets better at resisting the day-to-day loads you place on it. It does that through a very particular mechanism of a pathway called mammalian target of rapamycin (mTOR).
The one specific to muscle, mTOR complex 1 (mTORC1), is activated when muscles are stressed. When you stress a muscle, it experiences something called mechanotransduction. It’s a fancy word for, ‘I provide a mechanical stress on the muscle, and it provides a chemical signal to itself and to the brain.’ As a result, your brain will begin to contract more and more muscle …
Some people, when they retire, they just retire to the chair. Then they find themselves [asking] ‘Why can’t I move fast? Why am I losing my balance? Why am I unable to mow my lawn?’
There are a lot of changes happening, but fundamentally, a lot of them are happening in the muscle, because muscle is so metabolically active and requires good supply of regular nutrition, a good supply of exercise. If we’re not doing these things, we’re missing out.
BFR can help activate this mTOR pathway that helps to grow more and more muscle … You’re also building more capillary networks as muscle becomes more and more stressed.”
Benefits of Lactic Acid
As mentioned, BFR significantly increases lactic acid, which can cross the blood-brain barrier. Once you release the bands, the lactate travels in your blood to your brain, where a monocarboxylate transporter shuttles it into your brain to use it for fuel.2,3 It also increases brain derived neurotropic factor (BDNF),4 a brain growth factor that contributes to neuroplasticity and enhances cognitive performance.5,6
BFR also downregulates a hormone called myostatin, which is a negative regulator of muscle growth and mass.7,8,9 In other words, when your myostatin levels are high you cannot grow muscle. This is important because the elderly have levels twice as high as the young.10
In the past, lactate was traditionally viewed as a metabolic waste product, but today it is understood that lactate is an important molecule that is responsible for many metabolic processes and results in many structural adaptations. It is even referred to as a pseudo-hormone.11
The lactate that your Type 2 muscle fibers generate during BFR actually down-regulates the production of myostatin and helps improve skeletal muscle loss. Amazingly, BFR can decrease your myostatin levels by 45%,12,13 which has been shown to increase muscle protein synthesis.14,15,16 Novo explains:
“A simple way to view this is like a light switch. When you are in a state of injury, your body will shut off the mTOR building pathway, which will allow myostatin to become more active. Myostatin is a member of the TGF-beta family that is largely linked with the formation of scar tissue, another part of protein but not metabolically expensive.
In the military, they were already experimenting with drugs. One of them was losartan, in combination with platelet-rich plasma (PRP) to address the rate of scar tissue formation. What they noticed was that while administering losartan, which is a myostatin inhibitor, they were able to see [increased] rates of muscle growth and decreases in scar tissue.
The problem though was side effects. So, the next thought was, ‘What else inhibits myostatin?’ Exercise. As a result of inhibiting myostatin, it allows for the light switch to go on and allow for mTOR to become active to essentially aid in muscle building.”
KAATSU Versus Other BFR Devices
One of the greatest areas of controversy when it comes to BFR centers around the equipment used. KAATSU uses a special inflatable cuff device that can provide pulsed and continuous pressure.
When KAATSU was initially introduced into the U.S. in 2010, the device had a price tag of $16,000. Most physical therapists could not afford it so they used surgical tourniquets that already had FDA approval for surgery to substitute for KAATSU. Novo uses these wider tourniquet-type bands or devices.
KAATSU uses thinner inflatable elastic bands, so they stretch as you exercise. As a result, your blood flow, including your venous return, is not completely obstructed. The Delfi surgical tourniquet system Novo uses, which involves a static, nonelastic, wider band, is controversial in that it causes a near-complete obstruction of blood flow.
KAATSU leaders are quite opposed to it for this reason. One major concern is that the wider bands may increase the risk of blood clots. Another is that it could potentially create a hypertensive crisis in susceptible individuals. The KAATSU bands, because they’re elastic, doesn’t seem to cause that. Novo addresses these objections, saying:
“With BFR exercise, thus far we’ve not seen any increases in a clot formation or a deep vein thrombosis (DVT). There are studies that look at formations of tissue plasminogen activator (TPA), a clot-busting enzyme that has been viewed with BFR …
Mind you, the [BFR devices] used in the military are attached to a computer. So those systems actually regulate the pressure. Pressures go up and pressures go down [during the exercise]. So, as you contract against it, it pumps air. As you relax, it pumps it back up. In the U.S., the only company that does that is Delfi.
The device itself is essentially using the change in pneumatic pressure on the hose, right as your arm or your leg is pumping against the actual tourniquet. That change in air pressure is being read by the computer, and then the computer’s algorithm is adjusting the pressure as you exercise.
There’s another system in Europe called MAD-UP that does the same thing. But predominantly, a lot of the tourniquets used now in general treatment are round bladders that do give when you contract against them, but they’re not elastic. So, it’s not a hard cast-type bladder. It still has give to it. So, as you contract against it, the pressures will go up. And as you relax, the pressures go back down.
It’s different than an emergency tourniquet. That’s where KAATSU is right. We wouldn’t want to use an emergency tourniquet, which is essentially used for austere environments. Usually they’re made of canvas …
What we use in clinical care and in exercise are tourniquets that are very much in the same nature — they are meant to restrict venous flow. They’re meant to attempt to reduce arterial flow, but you have to understand that microcirculation is always occurring.”
To be clear, it’s important to not use a regular tourniquet, such as what you’d find in an emergency room, for BFR. Applied hard enough, the lack of elasticity could make it very dangerous, potentially causing a blood clot or nerve damage.
“Elastic BFR cuffs are safe to use. Tourniquets, austere tourniquets, that’s not at all to be used with this. Don’t apply it to yourself. Don’t apply it to anybody if you’re training them,” Novo warns.
BFR for Cardiac Rehab
Another magnificent benefit of BFR is its ability to promote the growth of new capillaries, thus improving your microcirculation, which is important for cardiovascular, heart and brain health. Your microcirculation tends to diminish with age, and BFR can go a long way toward maintaining healthy circulation.
In Japan, BFR is actually used for cardiac rehab, and in the U.S., Novo says there are some cases in which it’s been used to rehab after a heart attack. Like your brain, your heart can also use lactate as a form of fuel during ischemia or reperfusion injury. Novo explains:
“When we apply these BFR cuffs, we reduce the amount of blood returning back to the heart. That reduces stroke volume. Stroke volume is the amount of blood reentering the heart to be pumped out next. Stroke volume makes up one of the factors that allow us to understand cardiac output, with heart rate being the other factor.
Stroke volume times heart rate equals cardiac output. We would imagine that when we put these cuffs on — when we reduce blood flow, reduce stroke volume — that heart rate goes up to maintain cardiac output. Well, after a cardiac event, we essentially want the heart to work. It’s a muscle.
We want it to get a little stronger, but we don’t want it to have to pump so much blood that it’s put under more stress. It’s also that the tourniquets can reduce some of the stroke volume, hence reducing some of the actual stress volume that the heart stretches out to.
But the heart will have an elevation in heart rate that can actually help the heart to recover after the event — plus the benefit of the lactic acid acting as an energy for the heart to use during this period of time.
Chronically, we’re likely going to see benefits due to that same mechanism of reducing stroke volume and increasing heart rate, but then, in addition, down in the muscles, by improving the vascular network, which helps to have better oxygen diffusion and removal of waste products.
Ultimately, elderly individuals who apply [BFR] also get the additional benefits of increased strength and increased muscle size. Just putting on these cuffs and walking on a treadmill for 10 to 20 minutes a day … four to five days a week for four weeks, has very positive benefits for strength, size, cardiovascular function, blood flow into the actual limbs and, more importantly, improve measures of frailty. That means reducing your risk of falling …
And all of those positive benefits come by means of reducing sarcopenia, which is the normal age-related loss of muscle, and as well as reducing osteopenia, which is the, albeit not necessarily normal age-related loss of bone.”
Sample Protocol for Strength Building
While BFR is certainly ideal for the elderly, even competitive athletes stand to gain from it. According to the American College of Sports Medicine (ACSM), you need to use a weight that is 70% to 85% of your one rep max (1RM) if you want to build muscle and strength. With BFR, you’re using only 20% to 40% of your 1RM.
“The recommendations from the ACSM are quite well-researched,” Novo says. “When we train at those intensities, there are a lot of changes that happen to the tissue integrity of our body. Essentially, our body itself gets stronger at resisting those weights we use commonly.
When we’re not able to use those weights, using BFR can help to really set up a foundation to allow us to eventually progress back to them. With BFR, we can use weights that are as light as about 20% of your 1RM, or you would report as maybe being a 2 out of 10 in difficulty, where a 10 is only something you might be able to do one time.
A 2 is something that is relatively easy that you might be able to perform 30 to 40 times … If 2 out of 10 [is your] starting point, you’d want to progress upwards until you’re at about a 4 out of 10. That progression is necessary. Like with any exercise, we don’t want to be training at a weight that’s the same all the time, because eventually, we will plateau.
We want to kind of set forth a plan ahead of us, where we start at, maybe, body weight. We get used to what BFR feels like for about a week. We maybe do this for about three or four times that week.
We’ll mix it in where we have some exercises that are close-chain, like squats, some exercises that are open-chain, like knee extension and hamstring curls, and then throwing in some cardiovascular exercise; walking, riding a bike for five to 10 minutes.
By the time we get to Week 2, we want to try to start scaling that weight up. We’ve gotten used to it.
What it shows, also, is that your body becomes more metabolically resistant to the metabolic stress, because we have [both] mechanical stress and metabolic stress. BFR is high in metabolic stress, but your body will accommodate to it because of an increase in reactive oxygen species or heat-shock proteins …
Avoid [lifting to failure] in the second week … We don’t want to do that just yet, because at that week, if we start pushing failure … you’ll get really sore … Wait until you get to Week 3.
At that point, we’re going to really start working on going towards the higher weight, maybe 25% of a 1RM. Or we stay at 20%, but we’re now starting to hit failure. Failure allows us to increase in strength. That’s the key. If we’re not failing with BFR, we’re actually not increasing in much strength. A lot of that has to do with what defines neuromuscular strength.
Once we get to that 40% of that 1RM, we can start to pull back on BFR and start to expose ourselves to heavier loads without BFR. And then we can start mixing things. We call it the 80-20 rule, where at the beginning, 80% of the workload is going to be through BFR and 20% of the workload is not.
That 20% of the workload should work on things like isometrics, where there’s not a lot of movement occurring at the joint. There’s less muscle damage. But those isometrics are really beneficial for helping the bones and tendons to start catching up because, again, remember, with BFR, loads are lower.
You are increasing in neuromuscular strength, but your tendon doesn’t adapt the same way at all. Your tendons only adapt to pure mechanical stress. If the muscle’s contracting really hard, the tendons still has a lot more that it can tolerate … [Heavier loads] will help the tendon to start uptaking collagen and get thicker, so it’s able to keep up with the muscle …”
Now, if you’re elderly, it would be wise for you to revise this 80-20 rule to something like 60-40, where BFR makes up at least 40% of your fitness routine. The reason for this is because as you get older, your microcirculation diminishes.
By the time you’re in your 80s, you’re bound to have a fairly significant decrease is your w. For the elderly, having BFR make up just 20% of your exercise is likely to be too little, as conventional strength training has not been shown to increase microcirculation.
My BFR Recommendations
After careful review, it is clear to me that the KAATSU equipment is the best BFR equipment on the market, as it is the only one that allows you to do cycling or automatically cycling pressure on for 30 seconds and off for five seconds. You can review my comprehensive review on BFR from January 3, 2020.
The equipment used to be $16,000 when first introduced in the U.S. and even last year when I purchased mine it was $2,300. However, the new Cycle 2.0, which is the one I use every day, is now only $899.
Novo teaches formal courses on BFR around the country. At present, all live workshops are done through Novo’s company, The BFR Pros, which offers workshops for both performance and rehab. You can find more information about each class and register on theBFRpros.com.
“For right now, I am taking on individual clients so that they have a customized plan. You can access that by emailing me at [email protected],” Novo says. “The [online] store will have cuffs that you can purchase. Some of these cuffs are water-resistant. I work with swimmers. They actually have some very good protocols for the pool.
As well, there are some good protocols for post-menopausal women that have osteopenia that incorporate aquatics into what they do with BFR. I’m really trying to find a way to work at that one-to-one level.”
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