Blood flow restriction training is a technique that restricts blood flow in your arms and / or legs during exercise to help rehabilitate injuries, tendinitis, postoperative surgery (such as knee surgery), maintain strength during recovery, and even optimize performance for competitors. . When I was treating an injury while training for my last race, my physiotherapist used BFR training as part of my tendinitis recovery process. This was a tool I never used during other rehabilitation sessions.
The best way to describe it is this: Imagine having a blood pressure-like garter or cuff wrapped around each of your legs, making simple exercises (or at least they looked like it) much harder. The first time I tried this technique, my fours were much more painful than I expected the next day. The type of pain I felt was something I would usually feel a day or two after a day of intense squats.
After a few rounds of BFR training I noticed that the pain after training was not so strong and my legs were stronger and recovered. I was convinced that BFR training was on something and I was curious to learn more about the method. I was interested in a better understanding of how BFR training works, how it benefits people with different goals, as well as the risk factors associated with it. I spoke with Nicholas Rolnick, a physiotherapist and owner of The Human Performance Mechanic in New York, about the benefits of BFR training and how it works to help almost everyone (regardless of age and background) recover better and work out better in the gym. Read on to learn more about this popular rehabilitation technique.
How does blood flow restriction training work?
To perform BFR training, a specially designed velcro cuff is placed on your arm or leg (or both). To determine your personalized pressure, the cuff is connected to a manual machine that inflates the cuff to the point where blood flow is blocked in the limb. This is known as arterial or occlusive pressure of the limbs.
Once blood flow is restricted and the cuffs are detached from the handheld device, you can perform exercises with little or no weight and still create a “pump” similar to that when lifting heavy or performing many repetitions.
The purpose of restricting blood flow is to provide the same benefits as lifting heavy weights, such as increasing muscle mass and strength, through low-intensity training. As a result of this technique, your muscles work harder to contract and you will get tired sooner than if your blood flow is not restricted. This is a good thing because it means you will get the same benefits as hard training – but in a less intense way. Therefore, you are less likely to get injured while building strength safely.
During BFR training, Rolnik explains, you usually perform resistance exercises using four sets for each movement. “For example, you would do 30 reps in the first set and then three sets of 15 reps with a break of 30 to 60 seconds between sets,” he said. “BFR is usually applied continuously – which means that the applied pressure is released only when the last repetition of the fourth set is completed.”
This was the same format I followed when I used BFR training with resistance bar exercises. The band walks, bridges and raises his heels which would otherwise require twice as many repetitions to make me feel tired, before it felt challenging while my blood flow was limited.
Blood flow restriction training is performed by restricting the blood flow in your arms or legs with a garter or cuff like blood pressure wrapped around each of your limbs.
Giselle Castro-Freedom / CNET
Although research on BFR training and its effects on endurance training is not so convincing in terms of its benefits in resistance training, if you plan to use BFR while doing aerobics, Rolnick said there are several ways to do it. “Usually for aerobic exercise, it’s 10 to 15 minutes of low intensity or less than 50% of your VO2max,” he explains. VO2max refers to the maximum amount of oxygen you use during intense exercise. If you are interested in measuring your VO2 max, there are several ways to determine that number, such as a treadmill test or a walking / running test performed by your doctor.
Benefits of training to limit blood flow
In addition to gaining muscle mass and strengthening, there are many benefits you can get from BFR training.
“Other potential benefits include pain relief, [improved] cardiovascular capacity and even increased tendon and bone strength, ”Rolnick said.
There are other modalities of physical therapy such as instrumental soft tissue mobilization, kinesiotaping or ultrasound used in rehabilitation clinics. However, what makes BFR training unique is that there are many studies that continuously confirm how effective it is in different groups of people.
“If an exerciser effectively incorporates blood flow restriction into his routine, he can be guaranteed to create a positive change in his body,” Rolnick promises.
How long should you do BFR training?
BFR training aims to prevent muscle atrophy (loss of muscle mass) and encourage hypertrophy (gaining muscle mass), even when you are unable to lift heavy. “In a rehabilitation environment, BFR is typically applied six to eight weeks before moving on to strength training with a higher workload in those who need to lift heavy loads because of their lifestyle or sport,” Rolnick explains. According to research, this treatment has been applied to at-risk populations over an extended period of two to six months. In addition, recent studies conducted on patients with chronic kidney disease have shown that it is safe to do BFR training for up to six months under the supervision of a specialist.
It is unclear whether the same training recipe would be applied to unsupervised environments, but a BFR resistance and aerobic program of eight to 12 weeks is generally recommended. Whatever approach you choose, conducting a thorough screening process is key to reducing the risk of adverse events.
Who should or should not do BFR training?
BFR training is a universal tool that can help almost anyone. People who have trouble carrying or lifting heavier weights due to injury, surgery, other health problems, as well as joint or muscle pain, are good candidates for BFR training. Rolnick recommends a review by a BFR-trained service provider that can offer a detailed assessment of your medical history, physical activity history, and other factors that may be relevant to determine if you are a good candidate.
As with any treatment, there may be certain risks associated with BFR training. There is a small risk of muscle damage or an excessive cardiovascular response, such as high blood pressure. Rolnick said some risks can be prevented by modifying an individual prescription for BFR training as needed and ensuring that the provider performing BFR training is qualified.
For example, muscle damage can occur during strenuous BFR training, such as performing multiple sets of exercises until it feels difficult to complete. “BFR-trained providers understand that this risk is easily managed by avoiding exercise to failure and / or temporarily reducing the training load to allow the body to adapt and become more resilient,” Rolnick explains.
BFR training increases blood pressure during exercise, which is to be expected. However, for people with certain health problems, a better strategy could include applying less pressure, reducing pressure during the rest period, and avoiding multi-joint exercises.
Rolnick said: “This response may be exacerbated in those with certain health conditions and justifies considering other approaches to training and / or modifying BFR training prescriptions.” He suggests monitoring your blood pressure levels during the first few sessions to make sure your blood pressure doesn’t exceed critical values.
There have been security concerns about BFR training and blood clots in the past. But Rolnick said there is not enough evidence to show that BFR training increases the risk of blood clots, and instead may reduce the risk due to the way the body responds to temporary restraint and release during exercise.
Can BFR be done at home?

Smart Cuffs is one of the brands you can buy for home use.
Giselle Castro-Freedom / CNET
Similar to other forms of physical therapy, such as using a TENS machine, you can safely do BFR training at home. But it is important to first go through the screening process with a trained BFR provider to learn how to get the most out of your sessions.
“When BFR is performed properly, it’s embarrassing. So if you’re doing BFR and you don’t feel uncomfortable, it’s probably not doing anything,” Rolnick said. He explained that discomfort is the first signal that a useful stimulant for building muscle is appearing. “To promote adaptation, we need to push our physical and mental boundaries beyond that discomfort to expand our capacities and promote the benefits of muscle mass, strength and cardiovascular capacity.”
If someone uses BFR training for the purpose of relieving pain, they can be expected to feel discomfort such as pressure and some numbness in place during resistance training. Rolnick said that BFR training has a strong effect on pain relief reactions and that you should strive to achieve discomfort that is challenging but bearable, in order to maximize the therapeutic effect. However, excessive pressure or improper use of BFR tape can lead to burning or stabbing pain. This is something to watch out for because it can be a sign of nerve damage.
Take it away
BFR training is a useful option to keep in mind if you ever need to heal or strengthen after an injury. From personal experience, you definitely need to get a little used to it, because it is not everyday to do squats with partially interrupted blood flow. The good thing is that BFR training has been shown to be safe for most individuals, but if you have reservations, consult your physiotherapist or BFR-trained provider. In this way, you can get an appropriate assessment and get the most out of this type of therapy.
The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health care professional regarding any questions you may have about your health condition or health goals.