Blood Flow Restriction (BFR) training has gained popularity in physical therapy and sports medicine in recent years. There has been a lot of positive research regarding BFR and how to use it to improve recovery from injury and following surgery.
What is Blood Flow Restriction training?
Blood Flow Restriction (BFR) training is a training method that partially restricts arterial blood flow and fully restricts venous blood flow in muscles while performing exercise(8). BFR training involves using a tourniquet system, typically one that is pneumatic and similar to a blood pressure cuff, to apply pressure to the limb. With a pneumatic device, a healthcare professional can use an ultrasound doppler to find the exact amount of pressure to fully occlude blood flow. The pressure from the device is then reduced to a percentage, typically 50-80% of full limb occlusion pressure for the lower extremity and 30-50% of full limb occlusion pressure for the upper extremity, and the person then performs exercise while wearing the device. This should be done under professional supervision and may be contraindicated in certain situations or with certain individuals.
How Does Blood Flow Restriction Training Work?
Blood Flow Restriction training causes an ischemic and hypoxic environment in the muscle tissue. This creates increased muscular fatigue and therefore, requires the muscle to recruit more muscle fibers to generate the work required to perform the movement. Although the exact mechanisms of BFR are not fully understood it is proposed that the mechanisms of BFR include: elevated hormone production, cell swelling, production of reactive oxygen species, intramuscular anabolic/anticatabolic signaling pathways, increased fast-twitch muscle fibre recruitment, and satellite cell activity(9).
Benefits of Blood Flow Restriction Training
There have been numerous studies that have shown similar results between low load Blood Flow Restriction training and high load resistance training. Research continues to show an increase in muscle hypertrophy and strength with resistance training using BFR while using at 20-40% of 1 rep max at high repetitions. The increase in strength and hypertrophy is comparable to working at 80% of 1 rep max without BFR(8). BFR has also been shown to improve the vascular health of an individual when flow mediated dilation testing was performed along with strength and endurance of a muscle (3).
Blood Flow Restriction training has also been shown to be a safe and effective intervention for older adults to increase muscle mass, strength, as well as balance(1,7). With regards to post menopausal women, BFR training resulted in an increase in strength, balance, increased bone mineral density and bone turnover markers which may be beneficial for treatment for women with osteoporosis and osteopenia(7).
Blood Flow Restriction Training After Surgery
BFR with low load resistance may be beneficial in helping individuals recover following surgery. Often after surgery there are restrictions regarding the amount of load or resistance placed on a limb. Multiple studies have shown that BFR training has resulted in an increase in hypertrophy of the quadriceps as well as strength following ACL reconstruction surgery. Quadriceps atrophy and weakness are often a common complication following ACL reconstruction(2,4). Low load BFR training may also be beneficial in decreasing pain and have an analgesic effect which will help increase an individual’s tolerance to exercise and movement (6).
Contraindications of Blood Flow Restriction Training
While Blood Flow Restriction training has been found to be safe it is contraindicated with those with the presence of a blood clot and open wounds or infection in the limb. It is recommended to be cautious for individuals taking blood thinner medication, the presence of a stent or port in the limb, history of blood clots, and those with peripheral vascular impairment (5).
Resources
1. Centner C, Wiegel P, Gollhofer A, König D. Effects of Blood Flow Restriction Training on Muscular Strength and Hypertrophy in Older Individuals: A Systematic Review and Meta-Analysis. Sports medicine (Auckland, NZ). 2019;49(1):95-108. doi:10.1007/s40279-018-0994-1
2. Charles D, White R, Reyes C, Palmer D. A Systematic Review of the Effects of Blood Flow Restriction Training on Quadriceps Muscle Atrophy and Circumference Post Acl Reconstruction. International Journal of Sports Physical Therapy. 2020;15(6):882-891. doi:10.26603/ijspt20200882
3. Early KS, Rockhill M, Bryan A, Tyo B, Buuck D, McGinty J. Effect of Blood Flow Restriction Training on Muscular Performance, Pain and Vascular Function. International Journal of Sports Physical Therapy. 2020;15(6):892-900. doi:10.26603/ijspt20200892
4. Jacobson J, Chaltron C, Sherman D, Glaviano NR. Blood Flow Restriction Training in Clinical Musculoskeletal Rehabilitation: A Critically Appraised Paper. International Journal of Athletic Therapy & Training. 2020;25(6):303-306. doi:10.1123/ijatt.2019-0010
5. Johnny Owens. Owens Recovery Science. Blood Flow Restriction Rehabilitation Accessed from www.owensrecoveryscience.com
6. Korakakis V, Whiteley R, Giakas G. Low load resistance training with blood flow restriction decreases anterior knee pain more than resistance training alone. A pilot randomised controlled trial. Physical therapy in sport : official journal of the Association of Chartered Physiotherapists in Sports Medicine. 2018;34:121-128. doi:10.1016/j.ptsp.2018.09.007
7. Linero C, Choi S-J. Effect of blood flow restriction during low-intensity resistance training on bone markers and physical functions in postmenopausal women. Journal of exercise science and fitness. 2021;19(1):57-65. doi:10.1016/j.jesf.2020.09.001
8. Patterson et al. Blood Flow Restriction Exercise: Considerations of Methodology, Application, and Safety. Frontiers in Physiology. Volume 10. 2019. https://www.frontiersin.org/article/10.3389/fphys.2019.00533
9. THOMAS K. The Benefits of Blood Flow Restriction Training for Rehabilitation. Co-Kinetic Journal. 2019;(79):24. Accessed December 22, 2020. http://search.ebscohost.com/login.aspx?direct=true&db=edb&AN=133611279&site=eds-live