Blog

Blood Flow Restriction Training

Blood flow restriction training, or BFR, is far from a new discovery, however, its use in rehabilitation over the last decade has really come into culmination. The concept of blood flow restriction was initially discovered in 1966 by Yoshiaki Sato in Japan after he injured his lower leg and was placed in a cast for 6 weeks. He spent that time sitting cross-legged, as is common in Japanese culture, and essentially restricted blood flow to his lower leg. When the cast was removed 6 weeks later, he surprisingly had no atrophy. Fast forward to the early 90’s, and clinical units for blood flow restriction training started to enter the market, however, it wasn’t until around 2012 that this intervention really took off. 

Blood flow restriction training creates a hypoxic environment in the muscle, meaning an environment that lacks oxygen. This causes cellular swelling, activates protein synthesis, causes intramuscular anabolic signaling, increases growth hormone, and increases muscle fiber recruitment.1,2 Through these mechanisms, blood flow restriction training can elicit muscular hypertrophy and strength by using light external loads of 20-30% repetition maximum (RM).3 This is fundamental for creating adaptions in a tissue that may be load compromised or recovering from injury. For this reason, BFR has really gained popularity in the rehabilitation settings where the goal is to improve overall muscle hypertrophy and strength, even when you are dealing with the healing soft tissues and joint complexes.3 

The ability of a muscle to create force is going to be dependent on the balance between motor unit recruitment and development of muscular fatigue, due to the lack of oxygen delivery to the muscles.6 When lacking oxygen and under fatigue, the force producing capacity of exercising skeletal muscles are slightly altered.6 When exercising with BFR, there is a greater decline in the maximal voluntary isometric muscle contraction (see as a decrease in force production) compared to lower pressures or no BFR intervention at all.7 Especially under isometric conditions, the maximum voluntary contraction EMG amplitude is greatly reduced (72.5% vs. 46.3% of maximum EMG activity).4 However, in order to maintain force output levels during BFR when under accelerated fatigue, motor units of high threshold excitability are recruited, therefore a hypertrophic stimulus would be provided to a greater proposition of the muscle fibers creating an increased level of myoelectric activity in resistant exercise with BFR.8 The use of BFR targets the recruitment of Type II fast twitch muscle fibers4, the same type of muscle fiber that is first to atrophy. Furthermore, the addition of BFR has been shown to increase the neuromuscular activation and MVC (maximal voluntary contraction) of targeted muscles 15 minutes after BFR was applied.4,5 

BFR is an excellent tool across a variety of conditions and populations. BFR is great for individuals who have suffered from atrophy or are unable to train with heavy loads. It can be an essential tool following surgery where you may be non-weight bearing for several weeks or months. BFR with low loads is a safe and effective tool we utilize at Four Pines for musculoskeletal rehabilitation. Additionally, it can be used to build muscle hypertrophy and create adaptations in those already training but need to get in a strength/hypertrophy session without overloading their joints with heavy weights. Our clinicians are trained to utilize blood flow restriction training to meet your needs, goals, and personal aspirations. 

References: 

  1. Scott BR, Slattery KM, Sculley D V., Dascombe BJ. Hypoxia and resistance exercise: a comparison of localized and systemic methods. Sports Med. 2014;44(8):1037-1054. doi:10.1007/S40279-014-0177-7
  2. Yasuda T, Loenneke JP, Thiebaud RS, Abe T. Effects of blood flow restricted low-intensity concentric or eccentric training on muscle size and strength. PLoS One. 2012;7(12). doi:10.1371/JOURNAL.PONE.0052843
  3. Patel S, Amirhekmat A, Le R, Williams III RJ, Wang D. Osteochondral Allograft Transplantation in Professional Athletes: Rehabilitation and Return to Play. Int J Sports Phys Ther. 16:2021. doi:10.26603/001c.22085
  4. Lauber B, König D, Gollhofer A, Centner C. Isometric blood flow restriction exercise: acute physiological and neuromuscular responses. doi:10.1186/s13102-021-00239-7
  5. Nie J, Dankel SJ, Laurentino GC, et al. Blood Flow Restriction During Futsal Training Increases Muscle Activation and Strength. 2019. doi:10.3389/fphys.2019.00614
  6. Hammer SM, Alexander AM, Didier KD, Barstow TJ. The Journal of Physiology C 2020 The Authors. The Journal of Physiology C 2020 The Physiological Society. J Physiol. 2020;598:4293-4306. doi:10.1113/JP279925
  7. Head P, Waldron M, Theis N, David Patterson S. Acute Neuromuscular Electrical Stimulation (NMES) With Blood Flow Restriction: The Effect of Restriction Pressures. J Sport Rehabil. 2020;30(3):375-383. doi:10.1123/JSR.2019-0505
  8. de Queiros VS, de França IM, Trybulski R, et al. Myoelectric Activity and Fatigue in Low-Load Resistance Exercise With Different Pressure of Blood Flow Restriction: A Systematic Review and Meta-Analysis. Front Physiol. 2021;12:786752. doi:10.3389/FPHYS.2021.786752/FULL