Vascular occlusion or blood flow restricted training (BFR) is an exciting and emerging technique within the fitness and rehabilitation communities.
Known as Kaatsu training (for its founder Dr. Yoshiaki Sato) the technique is performed using a cuff (Kaatsu Master Device) which is inflated to about diastolic pressure (Fleck & Kraemer, 2014) with the purpose of preserving arterial inflow while occluding venous return during exercise (Beardsley, 2016; Fleck & Kraemer, 2014). However, in the gym, wraps, elastic bands, bands with numbers to provide an objective measure on compression, Velcro or quick-release cam buckles are used.
Blood flow restriction training in practice
For clarity purposes, if not using the Kaatsu Master Device, “occlusion training” or “blood flow restriction training” should be used (Beardsley, 2016). It has been suggested when using such occlusion training bands that the trainee uses a subjective measure of 7 out of 10 of wrap/band tightness to regulate the amount of occlusion (Beardsley, 2016). However, guidelines are hard to come by and specific recommendations lack scientific vigor.
There is data that suggest that a 40 -50% arterial occlusion must occur for positive adaptations to occur (Beardsley, 2016). Body anthropometry is a factor in inflation/occlusion as it has been shown that thigh circumference will affect occlusion. Based on these findings it seems as if circumference measures should play into calculating the target cuff tightness/pressures (Loenneke et al., 2014).
The pressure of occlusion counts
It has been demonstrated too much pressure may increase risk, but that insufficient pressure will not produce desired results. Some research suggests that inflation pressures of 240 mmHg are required for adaptation to occur and pressures of 180 mmHg did not achieve desired results (Beardsley, 2016). More data is needed to find optimal occlusion recommendations.
Training intensity needs to be adjusted
With BFR training intensities are significantly lower than typical training at about 20-50% 1RM (Beardsley, 2016; Fleck & Kraemer, 2014). Continuous occlusion did not show any benefits over intermittent occlusion so the exerciser may loosen the bands in between sets to lessen discomfort (Beardsley, 2016). The material that the band or cuff is made of has not been of importance.
Benefits of blood flow restriction training
BFR has demonstrated benefits when used with walking programs. Persons using occlusion training when walking experienced improvements muscle cross-sectional area and isometric strength whereas the non-occlusion group did not.
When comparing BFR and typical resistance training, at the same intensities, BFR has demonstrated greater muscle activity, post-exercise muscle protein synthesis, superior growth hormone increases, and more vigorous molecular signaling responses (Beardsley, 2016). Also, at the same intensities, BFR demonstrated improvements in strength and hypertrophy compared to without BFR (Beardsley, 2016). There may be some evidence that BFR can enhance muscular endurance and power (Beardsley, 2016).
Is it contraindicated?
Even though no studies have demonstrated significant risk and the method is though as safe (Novo, 2018), given the nature of the training method it is contraindicated for persons with deep-vein thrombosis, pregnancy, varicose veins, hypertension, and cardiovascular disease (Beardsley, 2016).
Beardsley, C. (2016, December 04). Blood flow restriction training. Retrieved from https://www.strengthandconditioningresearch.com/blood-flow-restriction-training-bfr/
Fleck, S. J., & Kraemer, W. J. (2014). Designing resistance training programs (4th ed.). Champaign, IL: Human Kinetics.
Loenneke, J. P., Allen, K. M., Mouser, J. G., Thiebaud, R. S., Kim, D., Abe, T., & Bemben, M. G. (2014). Blood flow restriction in the upper and lower limbs is predicted by limb circumference and systolic blood pressure. European Journal of Applied Physiology, 115(2), 397-405. doi:10.1007/s00421-014-3030-7
Novo, M. (2018, January 17). Blood flow restriction training for strength and hypertrophy. Retrieved from https://drjohnrusin.com/blood-flow-restriction-scientifically-advancing-muscular-strength-hypertrophy/
Rhea, M. R., Kenn, J. G., Peterson, M. D., Massey, D., SimÃ£o, R., Marin, P. J., . . . Krein, D. (2016). Joint-Angle Specific Strength Adaptations Influence Improvements in Power in Highly Trained Athletes. Human Movement, 17(1). doi:10.1515/humo-2016-0006
Tumminello, N. (2017, March 16). Retrieved from https://www.t-nation.com/training/partial-range-reps-not-always-cheating