Recent studies have suggested blood flow restriction, or BFR, works as well as standard methods of building muscle, even while lifting less weight. Nevertheless, when I ask people if they’ve tried it, the answer is always the same. There’s a lingering doubt in the back of their minds that if they try BFR, they will sacrifice their usual routine for something no one else in the gym is doing. Enter a recent study in the Journal of Strength and Conditioning Research, the first study I’ve seen that combines BFR with a regular exercise routine.
If you’re not familiar with BFR, let me take a moment to explain it. Essentially you apply a simple tourniquet, such as an elastic band, around your arm or leg. The tourniquet should be tight enough to restrict venous blood flow (the blood flow from your body to your heart), but not enough to fully prevent arterial blood flow (the flow from your heart to your body, which requires more pressure). When you exercise with this tourniquet, even with weights as low as 20% of your max, you’ll still see gains as though you had lifted much heavier weights. BFR has even been shown to increase size when paired with slow walking. Pretty crazy stuff.
The results of the latest study further demonstrated the usefulness of BFR. One group performed a traditional strength program, with an added session of bench press and squats at the end using BFR. The other group performed a strength program with no BFR. Sure enough, the BFR group did indeed experience greater strength gains than the one that did not use BFR.
The reasons for BFR’s effects aren’t totally known, but it seems to work for athletes at any level of ability. The theory is that the blocked blood flow increases the levels of metabolites (such as the waste products from exercise), and decreases available oxygen. This results in the recruitment of the most powerful muscle fibers, which are generally reserved for heavier loads. A further theory is that the cells swell up, stimulating anabolism.
However, it should be noted that although the athletes who used BFR were stronger, size gains were not improved in the BFR group. This result may be due to the limited BFR used in this program, how the tourniquet was applied, or the fact that the lifters were highly trained athletes.
Despite this one oddity, we have more evidence now that BFR is effective even when combined with an already-existing program. What we need now is a better understanding of how the average person can actually apply this knowledge in the gym. The researchers in this study recommend using an elastic band (they used powerlifting knee wraps) at a perceived tightness of seven on a one-to-ten scale.
1. Paul Luebbers, et. al., “The Effects of a Seven-week Practical Blood Flow Restriction Program on Well-trained Collegiate Athletes,” Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000385
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