What Is Blood Flow Restriction Training? (Advanced Training & Rehabilitation Technique)
Let’s quickly discuss with an emerging training and rehabilitation technique titled ‘blood flow restriction training’. This modality has been utilized by the US military for several years. You will be hearing more about this as it gains traction in professional sports and weight lifters.
What is blood flow restriction training?
The idea of restricting blood flow is built around a simple concept: increased blood flow to a muscle group improves oxygen and nutritional delivery; greatly improving it’s potential growth. This is well understood dogma in the world of athletics, weightlifting and rehabilitation. There are lots of approaches to achieving increased perfusion and blood flow restriction training is one of the emerging methods.
Blood flow restriction training (BFRT,), from a mechanical standpoint, occludes venous return from the muscles back to the heart without blocking the arteries. Ultimately, the venous blood pools in the occluded limb. This blocks the plumbing, allows arterial blood to pool in the capillaries increasing oxygen and nutrient extraction. You can use a blood pressure cuff, knee wraps, or anything really and wrap them around a limb to achieve this level of decreased flow.
What are the benefits?
There are some very significant implications to this technique. Perhaps the most important is in rehabilitation of injuries, for example in the military, where there are limitations in how much weight can be placed on a limb. Doing so allows you to decompress your joints, ligaments and tendons from the potentially brutal stress of high weight resistance training.
Using BFRT, one can achieve impressive anabolic gains using as little as 20% of your one rep max. In addition to injury prevention and rehabilitation, it almost certainly has utility in more traditional training regiments.
How does it work?
So from a technical point of view, there are some good resources out there that can better explain this process for those who are genuinely interested in the biochemistry and physiology of muscle fiber recruitment, but I will briefly summarize it.
Essentially, you are fatiguing your slow twitch muscle fibers (type I) by restricting blood flow. This forces your body to recruit more fast twitch muscle fibers (type 2), which have much more potential for growth. And from a metabolic perspective, you are achieving very similar effect to lifting heavy but are accomplishing it with much lighter weights.
Animal studies have shown that by forcing metabolic waste products to accumulate in the skeletal muscle as a result of occluded blood flow, there is an upregulation of human growth hormone. Similarly, there is an increase in muscle protein synthesis, reduce myostatin levels (good thing), and upregulated mTOR and NOS-1 signaling pathways. Accumulation of lactic acid in the muscle cells is also believed contribute to increased muscle growth.
How to use it?
The most practical applications are injured limbs where there are limitations to (a) the amount of weight you can use and (b) how much you are willing to stress the connective tissues of the joints involved. This is why it has gained traction in the military and is catching up in pro circles. For example, Houston Texans pro football players Jadaveon Clowney and Ryan Fitzpatrick are currently using it to rehab their injured knees.
Obviously, it also has a role in conventional exercise and weight lifting. I would certainly advise you to discuss it with your doctor or at least a personal trainer before you start using it. It should surprise no one that this is a painful approach as you are literally starving your muscles of oxygen every set and the buildup of waste products adds to the pain as well. There are some good videos and tutorials online if you’re interested in learning more.
As a final stamp, I will say that this is pretty cutting edge stuff really only taking off in the last few years. If you’re skeptical, do some more research.