Blood flow restriction training (BFRT) may allow for changes in strength, hypertrophy and endurance when used for an extended period of time without excessively loading the joint and soft tissue.
What is it?
BFRT is exercising at a sub-maximal load (20-40%) 1 Rep maximum (RM)) while using a cuff or a tourniquet to restrict arterial blood flow and occlude venous outflow(2).
This training method is used to increase strength, hypertrophy and endurance(2). This is thought to be advantageous for any populations who may not be able to train and load their bodies at higher intensities due to injury.
Where did it come from?
BFRT was originally developed in the 1970’s by Yoshiaki Sato in Japan, which he later called KATSUU training(14).
How does it work?
There are many hypothesized theories for why muscular adaptations take place with BFRT, however these have not all been proven. Whether or not these mechanisms work together or depend on the exercise stimulus is still to be determined.
Here are some proposed theories:
1. Reduced oxygen available to the muscle and metabolite accumulation can increase the threshold for type II fiber recruitment(9).
2. Accumulation of metabolites has been proposed to facilitate the increase in production of insulin-like growth factors and growth hormone(9).
3. Cell swelling is thought to cause a shift in metabolism towards a more anabolic state(6).
4. Increased production of reactive oxygen species by nitric oxide can help to stimulate muscle growth by activating muscle satellite cells(7)
Current Research Evidence
There has been research done looking at BFRT used with endurance-type training like walking and cycling. Sakamaki et al., (2011)(11), found that treadmill walking used with BFR caused significant changes in muscle hypertrophy when compared to a control group in just 3 weeks. Abe et al., (2010)(1), found that cycling using BFR caused greater changes in VO2 max, as well as muscle hypertrophy, when compared to a control group with 8 weeks of training.
Studies have also looked at BFRT with conditions such as: Knee Osteoarthritis(4), Patellofemoral pain syndrome(5), ACL reconstructions(10), and following an Achilles rupture(13). All of these studies have shown positive results with using BFRT – primarily with increasing strength, and muscle hypertrophy. Some of the studies also found significant improvements in pain and function when compared to resistance training at a high intensity.
Training Principles & Protocol
Although there is not a standardized protocol for this training method, the training principles and protocol below are reflected the most in the current research.
Frequency:
2-3 x/week clinical populations(12)
2-4x/week for athletic populations(12)
Intensity:
20-40% 1 RM(12)
Type:
Cycling(1), walking(11), low intensity resistance(12), and combined with traditional high intensity resistance training(12)
Time:
4-12 weeks (>8 weeks ideal for strength and hypertrophy changes)(3)
Protocol:
4 sets: 30, 15, 15, 15 repetitions(12)
Rest:
30-60 seconds in between sets(12)
Pressure:
Although 160-200 mmHg(7) is the most widely used in research, the pressure of the cuff should be individualized(8). You must take into account the individuals blood pressure, limb circumference and the size of the cuff(8) (wider cuffs restrict blood flow at lower pressures(12)).
Recommendations are: 130% of systolic blood pressure, and 50-80% occlusion of arterial blood flow if you have a doppler Ultrasound(12).
Another useful tip is making sure the participant can complete their goal number of repetitions per set - if they can’t, then the cuff is too tight(12).
References
1. Abe T, Fujita S, Nakajima T, Sakamaki M, Ozaki H, Ogasawara R, Sugaya M, Kudo M, Kurano M, Yasuda T, Sato Y, Ohshima H, Mukai C, Ishii N. Effects of low-intensity cycle training with restricted leg blood flow on thigh muscle volume and VO2 max in young men. Journal of Sports Science and Medicine. 2010; 9:452-458. http://www.jssm.org
2. Bowman EN, Elshaar R, Milligan H, Jue G, Mohr K, Brown P, Watanabe DM, Limpisvast O. Proximal, Distal, and Contralateral Effects of Blood Flow Restriction Training on the Lower Extremities: A Randomized Controlled Trial. Sports Health.2019;11:149-155. DOI: 10.1177/1941738118821929.
3. Day B. Personalized Blood Flow Restriction Therapy: How, When and Where can It Accelerate Rehabilitation After Surgery? Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2018;(34):8: 2511-2513. https://doi.org/10.1016/j.arthro.2018.06.022
4. Ferraz RB, Gualano B, Rodrigues R, Kurimori CO, Fuller R, Rodrigues Lima F, De Sa-Pinto AL, Roschel H. Benefits of Resistance Training with Blood Flow Restriction in Knee Osteoarthritis. Journal of the American College of Sports Medicine. 2018;897-905. http://www.acsm-msse.org .
5. 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 randomized trial. Br J Sports Med. 2017;51:1688-1694. doi:10.1136/bjsports-2016-096329
6. Loenneke JP, Fahs CA, Rossow LM, Abe T, Bemben MG. The Anabolic Benefits of Venous Blood Flow Restriction Training may be Induced by Muscle Cell Swelling. Medical Hypothesis. 2011;78:151-154. doi:10.1016/j.mehy.2011.10.014
7. Loenneke JP, Wilson JM, Marin PJ, Zourdos MC, Bemben MG. Low Intensity Blood Flow Restriction Training: a Meta-analysis. Eur J Appl Physiol. 2012;112:1849–1859. DOI 10.1007/s00421-011-2167-x
8. Loenneke JP, Wilson JM, Wilson GJ, Pujol TJ, Bemben MG. Potential safety issues with blood flow restriction training. Scand J Med Sci Sports. 2011; 21: 510-518. doi: 10.1111/j.1600-0838.2010.01290.x
9. Manimmanakorn A, Hamlin MJ, Ross J, Taylor R, Manimmanakorn N. Effects of low-load resistance training combined with blood flow restriction or hypoxia on muscle function and performance in netball athletes. Journal of Science and Medicine in Sport. 2012;16: 337-342.
10. Ohta H, Kurosawa H, Ikeda H, Iwase Y, Satou N, Nakamura S. Low-load resistance muscular training with moderate restriction of blood flow after ACL reconstruction. Acta Orthop Scand. 2003;74(1):62-68. https://doi.org/10.1080/00016470310013680
11. Sakamaki M, Bemben MG, Abe T. Legs and trunk muscle hypertrophy following walk training and restricted muscle blood flow. Journal of Sports Science and Medicine. 2011;10:338-340. http://www.jssm.org
12. Scott BR, Loenneke JP, Slattery KM, Dascombe BJ. Blood flow restricted exercise for athletes: A review of available evidence. Journal of Science and Medicine in Sport. 2016;(19) 360-367. http://dx.doi.org/10.1016/j.jsams.2015.04.014
13. Yow BG, Tennent DJ, Dowd TC, Loenneke JP, Owens JG.Blood Flow Restriction Training After Achilles Tendon Rupture. The journal of Foot & Ankle Surgery. 2018;57: 635-638. https://doi.org/10.1053/j.jfas.2017.11.008 14. Katsuu. Wikipedia. https://en.wikipedia.org/wiki/Kaatsu. Published Dec 3 2016. Accessed May 30th 2019.
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