How Does BFR Work?
In a sport where the majority of our time is spent figuring out how to increase blood flow, blocking it seems backward. How could that possibly that be beneficial? The short answer is that you should not completely restrict blood flow. That’s important to remember, so take a second to let it settle in.
Occlusion training involves wrapping a device like a pressure cuff or knee wraps around the top of a limb at a pressure sufficient to occlude, or obstruct, blood flow to the veins, but not the arteries.[2,3] This way, the arteries continue to deliver blood to the limb, and the blood pools in the limb as the veins struggle to take it back to the heart.
There are at least three ways that BFR works.[3, 5-7] You may have used the phrase “get my swole on” before—it’s OK, we all have—but you’ll really learn what it means once you apply a wrap. During BFR, muscle cells reach a point where they are so full of fluid that they have to either burst or grow.
The second way BFR works is that the low oxygen level in a muscle during the accumulation of blood forces your body to recruit larger fast-twitch fibers, resulting in extreme growth.
Finally, when oxygen is low, lactic acid rapidly accumulates. This may sound bad, but studies show lactic acid by itself can increase protein synthesis!