Blood Flow Restriction (BFR) Training: An Overview

Blood Flow Restriction (BFR) training involves applying external pressure to the extremities. This pressure is enough to maintain arterial inflow while occluding venous outflow distal to the occlusion site. The aim is to enable patients to make significant strength gains while lifting lighter loads, thereby reducing overall stress on the limb.

Origins of BFR

The concept of BFR originated in the 1960s with Yoshiaki Sato. He noticed his legs swelling while kneeling at a Buddhist memorial and felt sensations similar to those experienced during strength training. After a skiing accident in 1973, which resulted in fractured ankles, knee cartilage tears, and a torn MCL, Sato requested his doctor to put his legs in casts. He performed isometric exercises with periodic rest, leading to pressurization and depressurization. Upon removing the casts, he observed hypertrophy in his legs. In the late 1970s, BFR became popular among bodybuilders for achieving a "major pump." By the early 2000s, more research on BFR emerged, and it became common in limb salvage procedures. About a decade later, BFR gained popularity among professional athletes.

Benefits of BFR Training

Research has shown that BFR enhances muscle hypertrophy, increases strength, improves aerobic capacity, attenuates atrophy, and spares joints due to reduced loading (Patterson 2019, Bowman 2019, Hughes 2019, Korkmaz 2022). BFR reduces blood flow to muscles, increasing energy demand and deficit. This accelerates fatigue, producing metabolites and increasing Type II muscle fiber recruitment, resulting in greater strength and hypertrophy. Essentially, BFR tricks muscles into feeling maxed out with lighter loads, stimulating hypertrophy.

BFR for Rehabilitation

BFR is ideal for rehabilitation since high loads (> 60% 1RM) are necessary for increasing strength, but such intensity is not suitable immediately after surgery or injury. For example, BFR following ACL repair showed significant improvements in girth and knee extension and flexion strength compared to non-BFR groups (Ohta 2003). In patients with patellofemoral pain, a 93% reduction in pain with ADLs was observed after BFR-integrated PT (Giles 2017).

BFR for Performance

BFR can supplement or substitute for aerobic training, performed at 30-45% heart rate reserve for 10-20 minutes, 2-5 times per week (Patterson 2019, Hughes 2017). For resistance training, BFR is set at 20-40% 1RM with 75-90 reps (e.g., 30x15x15x15 scheme) with 30-60 seconds rest between sets, performed 2-3 times per week. BFR with low-intensity rowing (2x10 minutes, 3 times per week for 5 weeks) significantly increased VO2 max (Held 2020). Similar findings were reported in cyclists doing sprint intervals with post-exercise BFR (Mitchell 2019). High-intensity cycling with BFR improved function within Type I and Type II muscle fibers, reducing fatigability (Christiansen 2019). While no direct recommendations for BFR in performance training exist yet, the resultant increase in hypertrophy and strength could indirectly enhance performance.

BFR for Recovery

BFR has potential benefits for enhancing recovery. Ischemic preconditioning (IPC), a relative of BFR, involves 2-5 bouts of 4-5 minutes of compression followed by 5 minutes off, totaling 20-40 minutes. Studies in athletes have shown improved maintenance of muscle oxygenation during sprint cycling (Patterson 2015) and improved immediate and 24-hour post-swim and sprint performances (Beaven 2012). The suggested mechanisms include the release of factors that reduce blood pressure, calm the central nervous system, and lower creatine kinase levels, indicative of muscle damage (Luokogeorgakis 2005). Additionally, reports indicate reduced ATP depletion and lowered fatigue sensations (Crisafulli 2011). In summary, the body becomes conditioned to perform more with less, although further research is needed on the metabolic effects of IPC and BFR in athletes.

Conclusion

Overall, BFR offers numerous benefits, including increased strength and hypertrophy, attenuation of muscle atrophy, and improvements in bone density, cardiovascular function, and aerobic capacity. BFR provides the benefits of high-intensity training at low loads (20-40% 1RM) compared to traditional high loads (> 60% 1RM). While research in this area is still evolving, BFR shows promise as a beneficial adjunct to rehabilitation, performance, and recovery in athletes, continually optimizing outcomes for patient benefit.

Resources

-Patterson SD, Hughes L, Warmington S, et al. Blood Flow Restriction Exercise: Considerations of Methodology, Application, and Safety [published correction appears in Front Physiol. 2019 Oct 22;10:1332. doi: 10.3389/fphys.2019.01332]. Front Physiol. 2019;10:533. Published 2019 May 15. doi:10.3389/fphys.2019.00533

-Bowman EN, Elshaar R, Milligan H, et al. Proximal, Distal, and Contralateral Effects of Blood Flow Restriction Training on the Lower Extremities: A Randomized Controlled Trial. Sports Health. 2019;11(2):149-156. doi:10.1177/1941738118821929

-Hughes L, Rosenblatt B, Haddad F, et al. Comparing the Effectiveness of Blood Flow Restriction and Traditional Heavy Load Resistance Training in the Post-Surgery Rehabilitation of Anterior Cruciate Ligament Reconstruction Patients: A UK National Health Service Randomised Controlled Trial. Sports Med. 2019;49(11):1787-1805. doi:10.1007/s40279-019-01137-2

-Korkmaz E, Dönmez G, Uzuner K, Babayeva N, Torgutalp ŞŞ, Özçakar L. Effects of Blood Flow Restriction Training on Muscle Strength and Architecture. J Strength Cond Res. 2022;36(5):1396-1403. doi:10.1519/JSC.0000000000003612

-Ohta H, Kurosawa H, Ikeda H, Iwase Y, Satou N, Nakamura S. Low-load resistance muscular training with moderate restriction of blood flow after anterior cruciate ligament reconstruction. Acta Orthop Scand. 2003;74(1):62-68. doi:10.1080/00016470310013680

-Giles L, Webster KE, McClelland J, Cook JL. Quadriceps strengthening with and without blood flow restriction in the treatment of patellofemoral pain: a double-blind randomised trial. Br J Sports Med. 2017;51(23):1688-1694. doi:10.1136/bjsports-2016-096329

-Held S, Behringer M, Donath L. Low intensity rowing with blood flow restriction over 5 weeks increases V̇O₂max in elite rowers: A randomized controlled trial. J Sci Med Sport. 2020;23(3):304-308. doi:10.1016/j.jsams.2019.10.002

-Mitchell EA, Martin NRW, Turner MC, Taylor CW, Ferguson RA. The combined effect of sprint interval training and postexercise blood flow restriction on critical power, capillary growth, and mitochondrial proteins in trained cyclists. J Appl Physiol (1985). 2019;126(1):51-59. doi:10.1152/japplphysiol.01082.2017

-Christiansen D, Eibye KH, Rasmussen V, et al. Cycling with blood flow restriction improves performance and muscle K⁺ regulation and alters the effect of anti-oxidant infusion in humans. J Physiol. 2019;597(9):2421-2444. doi:10.1113/JP277657

-Patterson SD, Bezodis NE, Glaister M, Pattison JR. The Effect of Ischemic Preconditioning on Repeated Sprint Cycling Performance. Med Sci Sports Exerc. 2015;47(8):1652-1658. doi:10.1249/MSS.0000000000000576

-Beaven CM, Cook CJ, Kilduff L, Drawer S, Gill N. Intermittent lower-limb occlusion enhances recovery after strenuous exercise. Appl Physiol Nutr Metab. 2012;37(6):1132-1139. doi:10.1139/h2012-101

-Loukogeorgakis SP, Panagiotidou AT, Broadhead MW, Donald A, Deanfield JE, MacAllister RJ. Remote ischemic preconditioning provides early and late protection against endothelial ischemia-reperfusion injury in humans: role of the autonomic nervous system. J Am Coll Cardiol. 2005;46(3):450-456. doi:10.1016/j.jacc.2005.04.044

-Crisafulli A, Tangianu F, Tocco F, et al. Ischemic preconditioning of the muscle improves maximal exercise performance but not maximal oxygen uptake in humans. J Appl Physiol (1985). 2011;111(2):530-536. doi:10.1152/japplphysiol.00266.2011