What is it?
Blood flow restriction training (BFR) is the latest modality gaining traction in physical rehabilitation. Although it seems too good to be true, the practice of exercise under partial limb occlusion is holding up to research. The primary benefit seen with BFR is muscle hypertrophy with low relative mechanical loads. More recent research on BFR has been directed towards plausible mechanisms of action. The locally induced swelling of muscle cells with BFR is thought to improve local neural function via increased fiber recruitment, improve central neural function via increased cortical motor excitability, and increase muscle protein synthesis via increased metabolite accumulation.
Why consider using BFR?
Traditional resistance training guidelines recommend loads greater than 65% of the 1-repetition maximum (RM) to improve muscle mass and strength. However, many clinical populations are unable to tolerate heavier loading, making them susceptible to muscle atrophy, strength loss and functional impairment. Blood flow restriction (BFR) therapy has been shown to produce similar muscle mass and strength gains as heavier loading programs with less than 30% 1RM.
A meta-analysis study has revealed that BFR augments muscle mass and strength gains in clinical populations. Results show that the addition of BFR to low-loading programs is superior to low-loading alone. Statistical analysis showed that 69% of the population would experience greater gains in muscle strength with the addition of BFR to low-loading programs. However, when comparing low-load BFR training to heavy load training, heavy training is superior for strength (76% would show better results training heavy than with low-load BFR).
It can also reduce pain
In addition to the benefits of hypertrophy with reduced mechanical load, BFR has been shown to be efficacious in reducing pain acutely and improving movement tolerance. The benefit of improved exercise tolerance is also retained for the duration of the session, beyond the occlusion application time. BFR has been consistently shown to be an effective tool to load painful or restricted areas of the body and realize the benefits of exercise. Interestingly, the positive effects of occlusion have been observed in proximal synergistic muscle groups as well. BFR may therefore also be a helpful treatment tool for pathologies located on the axial skeleton including the shoulder, hip, and trunk.
Limitations
It is important to note that traditional heavy resistance training is still superior to BFR for its effects on muscle strength and high threshold motor unit recruitment. Progression to heavy-load resistance training continues to be the gold standard for long term improvements in strength and power. BFR has proven to be a helpful interim step in cases where heavy loading is contraindicated or not well tolerated. Despite the exercise-induced analgesia observed with the application of BFR, there is less compelling evidence to show it has an additive or lasting effect on the reduction of pain. The evidence at this stage does not support the use of BFR to replace resistance training in otherwise healthy populations and patients who can tolerate heavy loads.
Remember to always consult your health professional before proceeding with blood flow restriction training.
