Different perspectives on limb occlusion pressure (LOP). Arterial or venous?

A very popular question I will get from several clinicians is “When you pump up the B Strong BFR bands to 200 mmHg, what percentage of limb occlusion pressure (LOP) is achieved?” This is a valid question as many BFR bands are designed to occlude during the setup of the bands to determine a safe training pressure. With both B Strong and Kaatsu, a limb occlusion pressure isn’t achieved as the design of band allows the bands to be maximumly inflated without occlusion taking place. I go into this more extensively in Your overview to understanding 3 categories of BFR bands.

Why confusion tends to take place is due to the perspective taken when looking at applying pressure into the limb with BFR bands.  I will break down the two perspectives below which I’ve titled arterial perspective and venous perspective.

Arterial perspective

An arterial perspective places a high priority on the arteries when setting up the bands and determining a training pressure. An artery brings blood into the limb from the heart. 100% LOP is when the artery is completely closed and no blood flow is entering into the limb. Safe BFR training will take place at a certain percentage (ie 50% LOP) of full occlusion to allow blood flow to continue to come into the limb.    

Venous perspective

A venous perspective will focus on the veins when setting up the bands with a goal of manipulating venous blood flow. A vein returns blood to the heart from the limb. The artery is still respected as it is important to keep the artery open, but there is less concern with a certain percentage of the artery that remains open.

Can both perspectives be safe?

Yes. Safety can be achieved with applying either perspective as long as you are using equipment that accurately determines LOP or using a device that ensures the artery stays open. It is important that you are confident that blood is continuing to enter and exit the limb while the BFR bands are applied.

Can both perspectives be effective?

Yes. Research indicates that 40-80% of LOP is needed to produce outcomes(1) when you come from an arterial perspective. Using bands that are unable to determine percentage of LOP can still be effective as the bands slow blood flow, but they require monitoring the individual’s fatigue with exercise.  It is important to ensure the pressure in conjunction with the exercise selection produces the desired fatigue stimulus.

What is another example of how two different perspectives in strength training can yield similar results?

Programming for resistance training can successfully be applied from two different perspectives as well. The first perspective would be determining a 1 repetition max. This would test the individual’s ability to lift the maximum weight possible with a lift and then train at a percentage of that maximum. This perspective would be similar to the arterial perspective with BFR, where you start from the top and then train at a percentage of the maximum.

 A second perspective would be to estimate a load that would be challenging for the individual to complete the desired number of repetitions. The individual completes a set of the exercise, while their fatigue is monitored. If the load was too heavy or light, it is adjusted until the proper fatigue with the exercise is induced. This is repeated and methodically adjusted over time as the body adapts and gets stronger. This perspective would be similar to the venous perspective with BFR, where you start from the bottom and then gradually build up while staying below the maximum threshold. This individual may not know exactly, what percentage of their 1 repetition max they are training at, but they know they are making progress.

Conclusion

 Both of these perspectives can help an individual get stronger. One approach comes from the top down, while the other comes from the bottom up. It is very similar to BFR. Both can be individualized, both can be incredibly helpful, but the direct side-by-side comparison can be difficult.

(1) Lorenz DS, Bailey L, Wilk KE, et al. Blood Flow Restriction Training. J Ath Train. 2021; 56: 937-944.