Blood Flow Restriction Training and Therapy

BFR Training is gaining popularity due to its ability to halve the load needed for muscle growth. Emerging research supports its effectiveness in therapeutic settings.

1. Introduction and Mechanism of BFRT
2. Training Effects
3. Training Modalities (BFR + Walking, Low-load BFRT, Technique Work)
4. Alternative BFRT Implementations
5. Therapeutic Applications
6. Summary and Conclusion

Introduction and Mechanism of BFRT

In its essence, blood flow restriction (BFR) or occlusion training is a tool that is being used to form a reduced oxygen environment in a specific body part in order to increase metabolic stress. By "occluding" the proximal part of your limbs with the use of some cuffs, you diminish circulation (completely restrict venous return and partially restrict arterial blood-flow) distal from the occluded area. This hypoxia (oxygen deficiency) will lead to increased metabolite byproduct accumulation, which seems to work across different physiological pathways and is highly anabolic. And as it seems, this might work not only for the distal musculature (muscles below the cuff, where the blood flow is limited) but also for muscles located proximal to the cuff (although increases there are smaller) (Pavlou et al., 2023; Dankel et al., 2016).

Training effects:

To be safe, we recommend sticking to the most used techniques, which include cuffing your upper arm around the deltoideal tuberosity and the leg around the gluteal fold. Simply put a cuff around your limb and make sure it's tight enough to limit blood flow, but not too tight to completely restrict it. Perceived (subjective) pain can be higher for the lower limb than the upper. There should be no tingling occurring downstream from the cuffs, else the cuffs are too tight. On a pain scale from 1-10, the feeling of discomfort should be around a 7 (or between 160 and 220 mmHg), which has been shown to provide adequate compression (Luebbers et al., 2019).

When it comes to training intensity, a wider range has been shown to be effective for muscles distal to the applied cuffs (Pavlou et al., 2023; Dankel et al., 2016), and can go as low as 20% 1RM.

BFR training will make light weight training much more effective, as such it can also be seen as an intervention after an intense training period for strength athletes to reduce stress on the joints. Muscle building effects are the similar to normal resistance training, so it can be a fun training alternative. Or if you are travelling and are a pretty strong guy, the hotel probably won't have enough weights for you, use occlusion to make light weights feel heavy. In short, you are having an easier time to train effectively with light weight using BFR than without.

BFRT also increases bone formation markers, which can improve bone mineral density (which is correlated with an increase in bone mineral density) that have been shown to augment after low-intensity occlusion training (Karabulut et al., 2011). And as ageing comes with negative effects on bone health and sometimes osteoporosis (which makes heavy resistance training a contraindication), it can be counter-worked by using occlusion training. Even slow walking in combination with BFR has been shown to improve bone formation markers in adults (Beekley et al., 2005) and BFRT causes minimal muscle damage, making recovery easier (J. P. Loenneke et al., 2014).

When training for strength, adding BFR to your normal regime seems to lead to increased benefits (Yamanaka et al., 2012). And as as there seems to be happening virtually no muscle damage from this training style (J. P. Loenneke et al., 2014), it can be added to a training regime without taking an extra toll on your recovery. But adding BFR to a traditional lifting regime doesn't seem to elicit higher hypertrophy, only greater increases in strength, when implemented as accessory work.

Effect summary:

In simple terms, by adding BFR to any normal low-load training you will fatigue faster. Making your workouts more time efficient. If you can do 30 reps with a certain weight, by adding BFR you are likely able to be able to do less than 20. The funny thing is, that usually training tools are used to increase repetition output and not decrease the amount of reps you can perform. Also, training to failure is not necessary for BFRT to be effective. As a recent study showed, comparing two groups doing low-load BFR, of which one performed the training to failure and the other not to failure, no great differences have been found (Bjørnsen et al., 2021).

Training modalities (BFR + Walking, Low-load BFRT, Technique Work)

BFR + Walking:

Incorporating blood flow restriction during walking can enhance its impact and upgrade the impact that walking has on your body, particularly for adults looking to maximise the benefits of their walking routine. Research indicates that when walking is combined with blood flow restriction, it leads to notable improvements in muscle mass and performance compared to standard walking, making it a valuable option for individuals who cannot engage in heavy lower body training (Clarkson et al., 2017). Not only have studies demonstrated increases in muscle mass, but they have also revealed improvements in cardiovascular health parameters (such as HRV and systolic blood pressure) after a 6-week walking intervention (Ferreira Junior et al., 2019).

(An exemplary walking program would look like this: 5 sets of 3 min walking at 6km/h with 1 min of rest in between sets. Performed on 3 days per week. Cuffs stay on the whole training session, rest time included.)

Low-load blood flow restriction training:

Low-load (20-30% 1RM) BFRT has been shown to cause the same training effect regarding strength and hypertrophy as heavy resistance training (Luebbers et al., 2019; Grønfeldt et al., 2020). The type of training you do can vary individually. This means that when you occlude your upper limb, you can simply perform biceps curls or chose other compound movements such as the bench press. It's the same for the lower leg, you can just walk, do leg extensions or squat. It's up to you.

A typical training protocol we recommend for BFR comprises of 4 sets. Where the first set consists of 30 repetitions and the other three of 15 (30-15-15-15), with 30 seconds of rest in between sets (Schwiete et al., 2021). The load used for this program is usually around 20% and 30% of your 1RM. Therefore you could start at 20% and increase the weight by 5% every 2 weeks if possible. For pace, a 1,5 second eccentric and 1,5 second concentric is recommended. All that while opting for a weight that will take you at close to failure in your last set. If you feel like you are far from hitting failure, slightly increase weight.

Technique work:

When you are trying to improve your technique on certain lifts or movements, BFR can be used to train with lower load, meaning you can lay more emphasis on technique work, while still making progress from a strength and hypertrophy perspective for athletes, and while giving their joints a break.

Alternative BFRT implementations

One possible downside to BFR is, that it's a very mentally demanding exercise option. Not only are 30 reps to failure a heavy hit without BFR, but with BFR muscular pain will rise to another level (but so will the pump). So be prepared to suffer, as this is no easy feat. With short rest times and high reps, lactic acid will crash up and create an intense burning sensation, which doesn't make it the most comfortable training tool out there.
So for those trying to reduce the discomfort of BFR training, here are some (slightly less effective) alternatives:

Intermittent BFR: here, the cuffs are released during rest periods, which has been show to elicit similar gains, even though total time under BFR is reduced, and training is perceived more comfortable.

Resting BFR: here, cuffs are applied only during resting intervals, which is significantly less pailful for trainees, due to reduced absolute metabolic stress. This method is still effective due to a scenario researchers call "metabolic freeze", where the muscle pump is being held there for the time of the rest interval and therefore unable to be worked off by circulation (Schwiete et al., 2021).

Therapeutic Applications

The most obvious reason to include BFRT in rehab is that low loads are easier to move for most people with pain.
As the loads utilized in BFR training are around 20-30% of 1RM and thus significantly lower than usual training loads needed to build muscle (60+% of 1RM). Therefore, using high enough loads to increase muscle circumference can be pretty demanding if not impossible and counterintuitive for an injured person or athlete. And there already exists plenty of data showing its effectiveness with patients. It should therefore be included in therapy more often by the general practitioner. As BFRT has been found to be as effective as normal resistance training in different patient groups, such as with knee osteoarthritis or after knee surgery (Wengle et al., 2022).

Is it safe?

Yes. As long as only the two recommended spots are being used for occlusion it can be stated that it is an evidence based and save training method.
(Applying the cuffs at other locations will probably be fine as well, just always be aware at how it feels and stay below an acceptable pain threshold (at or below a 7 out of a 1-10 pain scale)).

Caution should be taken only if you are a person who is either extremely out of shape or dealing with high blood pressure problems, as these two factors could prove to be problematic. Although BFR has been indicated to also be an effective training method for reducing high blood pressure (as most activities do), we still caution you to start BFR if you have more severe problems with blood pressure. But if you do it, cuff pressure will need to be even lower than a 7 out of a 1-10 pain scale (which is usually recommended).

BFRT after surgery:

A couple of studies have been conducted on the use of occlusion training after lower limb surgery, with astonishing results. The below model will highlight the most interesting and important effects when implementing BFR into a post-surgery rehabilitation program.

Exemplary progression model for after surgery from Loenneke (Loenneke et al., 2012):

1. In his paper the author explains how BFR per se (alone, without any exercise) is enough to minimise muscle atrophy in people who are immobilised, or too weak to begin even low-load exercise. This would make up the first step in an intervention (exemplary protocol: cuffs are applied for a total of 25 minutes per day, split up into 5 x 5 minute sessions with 3 min rest in between, while performing no movement of any kind) and has been shown to be a countermeasure to cardiovascular deconditioning.
2. Second, BFR slow walking can be used to measure significant gains in muscle mass as well as bone health, especially in the untrained. Or when patients are not yet strong enough to do resistance training, walking with BFR is a worthwhile training option. (exemplary protocol: 20 minute treadmill walking at 45% heart-rate-reserve (=moderate intensity) with cuffs on. Occlusion pressure can be slightly augmented each week as a progression (Ozaki et al., 2011))
3. Then, once the patient is able to handle greater loads, low-load BFR training is initiated. And as this training style is not associated with a greater health risk than heavy load training, it is recommended in this stage of rehab, as lighter weights can be used for the same effect. (exemplary program: 4 sets of 30-15-15-15 repetitions with 30 seconds of rest in between sets, cuffs stay on during the whole time (rest periods included))
4. Finally, in the last stage, low-load BFRT is performed in combination with high-load resistance training. Like this we are slowly implementing high-load exercises, which are highly beneficial for tendon stiffness, and are therefore still an important part of any rehab routine. (exemplary program: switch between heavy loads and low-load BFR either in between sessions, meaning you start with heavy loads and finish with low-load BFR, or switch between only low-load and only heavy-load sessions throughout the week)

Important caveat: when BFR is used in training with patients, the intensity should always be submaximal. Meaning that training sessions should not be taken to failure when starting out. But over time, intensity and effort can be individually progressed, with the end-goal of reaching the standard protocol: 4 sets of an exercise with 30, 15, 15 and 15 repetitions (Loenneke et al., 2012).

Summary and Conclusion:

BFR can be used to reduce atrophy in the immobilised or in people with incomplete spinal cord injuries, which can therefore possibly minimise the total time needed for rehabilitation, as quicker gains in strength due to greater remaining muscle mass will likely increase speed of functionality regain. Then it can be used as a tool to increase effectivity of walking, especially in less trained populations. And last but certainly not least can it make low-load training much more effective while simultaneously giving your joints a break.

Remember, occlusion training is just as effective as regular resistance training for muscle growth, but it's not necessarily better. This means it is an effective method for building muscle, but not superior to traditional resistance training for healthy individuals. This article has tried to make clear how BFR works and point out its effectiveness and simple to use mechanism. We want to inspire therapists and trainers to add occlusion training into their toolbox, as it has been shown multiple times to be save and effective (and cheap).

BFR can attenuate the effects of sarcopenia, have a positive effect on bone health and act as a surrogate for heavy load training, thereby enabling more people to lift, especially for those who are in pain.

Low-load BFR is more effective than low-load training without BFR and more tolerable than high load training in rehabilitation settings, making it a great and convenient exercise option.

So, is it the ultimate training method you need? Not necessarily, but it's a valuable tool that can easily be implemented into practice.

References:

Clarkson, M. J., Conway, L., & Warmington, S. A. (2017). Blood flow restriction walking and physical function in older adults: A randomized control trial. Journal of Science and Medicine in Sport, 20(12), 1041–1046. https://doi.org/10.1016/j.jsams.2017.04.012

Dankel, S. J., Jessee, M. B., Abe, T., & Loenneke, J. P. (2016). The Effects of Blood Flow Restriction on Upper-Body Musculature Located Distal and Proximal to Applied Pressure. Sports Medicine (Auckland, N.Z.), 46(1), 23–33. https://doi.org/10.1007/s40279-015-0407-7

Ferreira Junior, A., Schamne, J. C., Altimari, L. R., Okano, A. H., & Okuno, N. M. (2019). Effect of walk training combined with blood flow restriction on resting heart rate variability and resting blood pressure in middle-aged men. Motriz: Revista de Educação Física, 25(2), e101945. https://doi.org/10.1590/s1980-6574201900020005

Pavlou, K., Korakakis, V., Whiteley, R., Karagiannis, C., Ploutarchou, G., & Savva, C. (2023). The effects of upper body blood flow restriction training on muscles located proximal to the applied occlusive pressure: A systematic review with meta-analysis. PloS One, 18(3), e0283309. https://doi.org/10.1371/journal.pone.0283309

Hughes, L., Paton, B., Rosenblatt, B., Gissane, C., & Patterson, S. D. (2017). Blood flow restriction training in clinical musculoskeletal rehabilitation: A systematic review and meta-analysis. British Journal of Sports Medicine, 51(13), 1003–1011. https://doi.org/10.1136/bjsports-2016-097071

Luebbers, P. E., Witte, E. V., Oshel, J. Q., & Butler, M. S. (2019). Effects of Practical Blood Flow Restriction Training on Adolescent Lower-Body Strength. Journal of Strength and Conditioning Research, 33(10), 2674–2683. https://doi.org/10.1519/JSC.0000000000002302

Schwiete, C., Franz, A., Roth, C., & Behringer, M. (2021). Effects of Resting vs. Continuous Blood-Flow Restriction-Training on Strength, Fatigue Resistance, Muscle Thickness, and Perceived Discomfort. Frontiers in Physiology, 12, 663665. https://doi.org/10.3389/fphys.2021.663665

Beekley, M. D., Sato, Y., & Abe, T. (2005). KAATSU-walk training increases serum bone-specific alkaline phosphatase in young men. International Journal of KAATSU Training Research, 1(2), 77–81. https://doi.org/10.3806/ijktr.1.77

Karabulut, M., Bemben, D. A., Sherk, V. D., Anderson, M. A., Abe, T., & Bemben, M. G. (2011). Effects of high-intensity resistance training and low-intensity resistance training with vascular restriction on bone markers in older men. European Journal of Applied Physiology, 111(8), 1659–1667. https://doi.org/10.1007/s00421-010-1796-9

Wengle, L., Migliorini, F., Leroux, T., Chahal, J., Theodoropoulos, J., & Betsch, M. (2022). The Effects of Blood Flow Restriction in Patients Undergoing Knee Surgery: A Systematic Review and Meta-analysis. The American Journal of Sports Medicine, 50(10), 2824–2833. https://doi.org/10.1177/03635465211027296

Loenneke, J., Abe, T., Wilson, J., Thiebaud, R., Fahs, C., Rossow, L., & Bemben, M. (2012). Blood flow restriction: An evidence based progressive model (Review). Acta Physiologica Hungarica, 99(3), 235–250. https://doi.org/10.1556/APhysiol.99.2012.3.1

Grønfeldt, B. M., Lindberg Nielsen, J., Mieritz, R. M., Lund, H., & Aagaard, P. (2020). Effect of blood‐flow restricted vs heavy‐load strength training on muscle strength: Systematic review and meta‐analysis. Scandinavian Journal of Medicine & Science in Sports, 30(5), 837–848. https://doi.org/10.1111/sms.13632

Luebbers, P. E., Witte, E. V., Oshel, J. Q., & Butler, M. S. (2019). Effects of Practical Blood Flow Restriction Training on Adolescent Lower-Body Strength. Journal of Strength and Conditioning Research, 33(10), 2674–2683. https://doi.org/10.1519/JSC.0000000000002302

Bjørnsen, T., Wernbom, M., Paulsen, G., Berntsen, S., Brankovic, R., Stålesen, H., Sundnes, J., & Raastad, T. (2021). Frequent blood flow restricted training not to failure and to failure induces similar gains in myonuclei and muscle mass. Scandinavian Journal of Medicine & Science in Sports, 31(7), 1420–1439. https://doi.org/10.1111/sms.13952

Loenneke, J. P., Thiebaud, R. S., & Abe, T. (2014). Does blood flow restriction result in skeletal muscle damage? A critical review of available evidence. Scandinavian Journal of Medicine & Science in Sports, 24(6). https://doi.org/10.1111/sms.12210