Blood Flow Restriction Training During the COVID-19 Crisis

The challenges facing our elite athletes during the COVID-19 lockdown protocols have been well-publicized. The cancellation of major events and competitions has captured the attention of mainstream media, while fitness enthusiasts have bombarded the social media world with a barrage of “stay fit from home” workout routines. These challenges are no different for us at Edinburgh Rugby where we face the reality of having to prepare our players for elite-level rugby competition from the comforts of their living room, often with minimal exercise equipment. Blood flow restriction training (BFR), otherwise termed “KAATSU” was developed in Japan in 1966 by Dr. Yoshiaki Sato, as a unique strategy to maintain muscle mass during injury immobilization. Since then a large body of research has evolved supporting the use of BFR as a training strategy to optimize adaptations to training. BFR is typically used in combination with low-intensity resistance exercise, or cardiovascular training and has been shown to promote many positive adaptations within the musculoskeletal, cardiorespiratory, and vascular endothelial systems. Muscle mass is critically important in rugby union. The best players are strong, fast, and they win collisions, all qualities underpinned by a healthy muscle mass. To build muscle the body requires one of two things: a high mechanical load (typically considered >70% 1RM), and/or resistance exercise to muscle failure. If we consider lower body muscle mass, many of our players will back squat in excess of 200kg so training above 70% of a 1RM in their living room presents some challenges. BFR training with intensities of as little as 20% 1RM has been shown to elicit improvements in muscle mass in athletic populations that are equivalent to conventional strength training at 70% 1RM (Takarada et al. 2004). For this reason, BFR provides us with a useful strategy to maintain muscle mass in our athletes with minimal training equipment. The protocol we prescribe is as follows:

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• Occlusion pressure – 70% limb occlusion pressure
• Volume – 4 sets, completed as 30, 15, 15, failure with 1min rest
• Total time under occlusion 5-7mins
• Load – 30% 1RM – or failure between 10-20 reps on final set
• Exercise selection – Target 2-3 exercises recruiting a large muscle mass: squats, lunges, RDLs

*Our first option will be to progress the amount of load lifted to continue to progress the mechanical load imparted on the athlete. If this is not possible due to a lack of equipment, we will progress total time under occlusion. An emerging body of research suggests that we could likely achieve the same outcome by completing regular low-load strength training to failure (Pignanelli et al. 2020). While this is a training strategy that we certainly implement within our programme, consistently performing this method of training has limitations. Training to failure at low loads (20-30% 1RM) is likely to cause a high amount of central nervous system fatigue due to the high number of repetitions performed. Compared to this method of training, BFR involves less CNS fatigue because the number of repetitions the athlete can complete is much less. This means we can continue to prioritize other aspects of our training that remain important during the lockdown. A further challenge that we will face upon return to training and competition following the lockdown, will be re-building running and training loads in a safe and progressive manner. While there are many factors that contribute to injury risk modification, at a very basic level, a strong and fatigue resistant muscle will be less likely to suffer an injury. If we can maintain these qualities during the lockdown, the challenge that awaits us when we return will be much easier to overcome. We can learn from the example of the 2011 NFL lockout which lasted 132 days. Upon return to competition, there were 12 Achilles tendon ruptures in 1 month, while the normative average is 5 ruptures per year (Myer et al. 2011). While this is an extreme case, we are in an extreme situation. At Edinburgh, we have players with extensive injury histories that make them more susceptible to injuries in the future. During the COVID lockdown, we will use BFR training in bespoke individuals with specific injury profiles. For example, athletes that present as a higher risk for calf/Achilles tendon injury will complete the following protocol:

• Occlusion pressure – 50% limb occlusion pressure
• Volume – 3 sets completed to failure with 1min rest
• Total time under occlusion
• Load – Typically performed at body weight
• Exercise selection – Single leg heel raises (completed off a step) and bent leg soleus raises

This protocol was derived from Patterson and Ferguson (2010) and has been shown to increase calf 1RM strength, muscle mass, and microvasculature. As an additional benefit, Centner et al (2019) recently demonstrated that a similar protocol was able to cause adaptations in the Achilles tendon, which was previously thought to require a high-load training stimulus.

By implementing BFR training using the SujiBFR system we are ensuring that we give our players at Edinburgh Rugby the best chance to return from the COVID-19 lockdown fit, strong and most importantly durable, and ready to get back to training in the new world.

Takarada, Y., et al., Cooperative effects of exercise and occlusive stimuli on muscular function in low-intensity resistance exercise with moderate vascular occlusion. The Japanese Journal of Applied Physiology, 2004. 54: p. 585-592. DOI: 10.2170/jjphysiol.54.585

Pignanelli, C., et al., Low-load resistance training to task failure with and without blood flow restriction: muscular functional and structural adaptations. Am J Physiol Regul Integr Comp Physiol, 2019. 318: p 284-295. DOI: 10.1152/ajpregu.00243.2019 Myer, G. D, et al., Did the NFL Lockout Expose the Achilles Heel of Competitive Sport, Journal of Orthopaedic & Sports Physical Therapy, 2011. 41(10): p. 702-705. DOI: 10.2519/jospt.2011.0107