Blood Flow Restriction Training: Just a fad, or a future in PT
Recently more and more articles about Blood Flow Restriction Training (BFR) have surfaced, especially on social media. A few patients have asked about BFR, how it can be used, and its benefits. BFR is a technique used to produce hypertrophy of a muscle, or muscle group, by restricting venous blood flow from leaving that area. This practice has been around for many years, but typically has been used by body builders and other athletes in order to gain muscle quicker. Over the last few years, research has shifted to talk about benefits of BFR in more of a rehabilitation setting (ie: Physical Therapy for individuals who are post-operative ACL reconstruction, lower extremity pain and weakness, and other diagnoses).
You may be asking yourself, how does restricting blood flow help to build muscle? And, don’t you want blood going to your muscles when trying to increase strength?
Yes, in order to build muscle you must have oxygenated blood flowing to that area. The idea behind BFR is that you are only restricting the venous blood flow from escaping that area, not occluding the arterial blood flow from getting there. For those unfamiliar with the circulatory system, arteries carry blood filled with oxygen to muscles and tissues, while veins bring it back to the heart.
The reason you restrict venous blood flow is to cause a pooling of the blood and lactic acid around the muscle. Having an influx of blood and lactic acid causes your cells to increase in size. This increase in size can cause a metabolic stress on the cells, which in turn, increases the cell’s production of protein and stimulates an individual’s growth hormone. Stimulation of your growth hormone and production of protein will both help to build muscle quicker.
The technique requires a band or cuff that you place around a muscle. To only restrict venous blood flow you tighten the cuff until it feels like a 7/10 on a perceived pressure scale. The band should be tight, but not too tight that it is very uncomfortable or you begin to notice any numbness or tingling into the extremity. Once the cuff is on and tightened properly, you begin to perform an exercise. You should perform 15-30 repetitions, for 3-4 sets, with 20-50% your 1 rep maximum resistance. Rest for at least 30 seconds in between sets. For example, if you want to strengthen your quadriceps you would put the cuff around your upper quads and perform a seated leg extension. See ex below:
So, is this appropriate for people rehabilitating from an injury? As a part of physical therapy, a full screen should be performed on each individual whom may benefit from BFR. Contraindications include people with high blood pressure, history of a DVT/blood clot, pregnancy, cardiac diseases, or other significant co-morbidities. Specific individuals who may be appropriate are patients recovering from an ACL injury, patients with patellar tracking issues, various upper extremity injuries, or in a patient who is de-conditioned. The benefit of performing BFR on these people is that you are doing exercise at a low intensity (20-50% max rep), with a low load. It is common that patients have difficulty performing certain weight bearing exercises due to the increased stress on your joints. Adding BFR may contribute to an increase in muscle strength, with less irritation to a patient.
While this may sound like a great option, BFR is a new treatment in the rehab world. The current available research is still relatively new and only contains information from the last few years. Physical Therapy is a field that heavily values evidence based practice and those practices tend to be supported by many years of evidence/research. As new evidence emerges, more research on the topic is usually done over a longer time period. Further studies should be conducted to determine the validity of BFR at this time. I believe this treatment will grow and become more popular within the next few years. Keep your eyes open, as Blood Flow Restriction Training may truly be part of the future for Physical Therapy.
Sources
Blood Flow Restriction Training After Knee Arthroscopy: A Randomized Controlled Pilot Study.
Tennent DJ, Hylden CM, Johnson AE, Burns TC, Wilken JM, Owens JG.
Clin J Sport Med. 2017 May;27(3):245-252. doi: 10.1097/JSM.0000000000000377.
PMID: 27749358
Egerton, Tim. “Blood Flow Restriction Training.” Strength & Conditioning Research. Strength & Conditioning Research, 04 Dec. 2016. Web. 24 May 2017.
Wilson, Jacob. “Jake Wilson’s Project Mass: Blood Flow Restriction Training.”Bodybuilding.com. Bodybuilding.com, 12 May 2017. Web. 24 May 2017.
