The Science of Blood Flow Restriction (BFR) Training

Blood Flow Restriction/Occlusion Training

What You’ll Takeaway –

1. BFR involves wrapping cuffs or wraps around the top of a limb to create sufficiency pressure to obstruct blood flow

2. BRF causes growth via increase metabolite build up, a mechanism of muscle growth.

3. The advantages BFR has over heavy lifting is it does not cause muscle damage, and therefore can lead to easier and quick recovery from a session. This can be very beneficial for rehab or elderly individuals.

4. BFR does not replace your heavy training!

This is a type of training that involves restricting blood flow to the target muscle to cause a stimulus to cause an increase in muscle growth and strength.

We know blood flow is essential for life and we are always told that we want our muscles to have lots of blood flowing to them whenever we are playing a sport or working out, so how can BFR be beneficial?

BFR involves wrapping a cuffs or wraps around the top of a limb to create sufficient pressure to obstruct, blood flow to the veins, but not the arteries. (1,2) The blood, therefore, pools in the muscle.

BRF allows you to create a stimulus to your muscles with very lightweight when performed correctly. It can increase muscle size and strength using training loads as light as 20% of a 1 rep max. (3)

BRF causes growth via increase metabolite build up, a mechanism of muscle growth. These metabolic by-products would normally be ‘washed out’ by normal blood flow, but occlusion allows them to accumulate near the muscle. (4-5). BFR also pre fatigues your slow twitch muscle fibers which are recruited first at the start of a set and forcing the bigger, more responsive to growth, fast twitch fibers witch fibers.

The advantages BFR has over heavy lifting is it does not cause muscle damage, and therefore can lead to easier and quick recovery from a session. Meaning frequency of training or volume can increase on your heavy training.

One problem with a lot of the research into BFR is that it is not tested in trained athletes. I would like to, therefore, share an extract from Alan Aragon’s Research Review March 2012, reading this topic (seen below.) This is a problem because the stimulus and relative loads that are required to cause in increase in size and strength differ between trained and untrained athletes.

*For anyone interested in the research of nutrition and training I highly recommend  Alan Aragon’s Research Review

Should I Just Use BFR?

BFR does not replace your heavy training but goes with it, to aid your accessory work. I am not using BFR every day and every set. I use it once per week for 3 sets on my arms at the end of a session, after having lifted heavy with loads of approximately 70-80% of my 1RM.

It has been shown in the research that a variety of rep ranges (6) will be best for improving strength and size, targeting all the mechanisms of muscle growth (damage, tension, and metabolic stress.) This is why solely using occlusion training (reps of 20+) would not be ‘optimal.’

The load is important to anyone wanting to increase size and strength and as we become more experienced at lifting the required percentage of our 1RM to create a sufficient stimulus increases. Rhea at al. (7) found that to produce the best results in trained and untrained individuals, individuals would have to lift loads around 80% and 60%, respectively, of their 1RM.

* One point to note about BFR is to not wrap to tight as it can be very painful and cause huge problems. It is advised that you wrap to a tightness of about 7/10.

References

1. Wilson JM, Lowery RP, Joy JM, Loenneke JP, & Naimo MA (2013). Practical Blood Flow Restriction Training Increases Acute Determinants of Hypertrophy Without Increasing Indices of Muscle Damage.J Strength Cond Res, epub ahead of print.
2. Loenneke JP, Abe T, Wilson JM, Ugrinowitsch C, & Bemben MG (2012) Blood flow restriction: how does it work?Front Physiol, 3, 392.
3. Loenneke JP and Pujol TJ. The Use of Occlusion Training to Produce Muscle Hypertrophy. Strength & Conditioning Journal. 31(3): 77-84, June 2009.
4. Takarada Y, Nakamura Y, Aruga S, Onda T, Miyazaki S, and Ishii N. Rapid increase in plasma growth hormone after low-intensity resistance exercise with vascular occlusion. J Appl Physiol 88: 61–65, 2000.
5. Takano H, Morita T, Iida H, Asada K, Kato M, Uno K, Hirose K, Matsumoto A, Takenaka K, Hirata Y, Eto F, Nagai R, Sato Y, and Nakaajima T. Hemodynamic and hormonal responses to a short-term low-intensity resistance exercise with the reduction of muscle blood flow. Eur J Appl Physiol 95: 65–73, 2005
6. Schoenfeld BJ1, Ratamess NA, Peterson MD, Contreras B, Sonmez GT, Alvar BA. Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men. J Strength Cond Res. 2014 Oct;28(10):2909-18.
7. Rhea MR1, Alvar BA, Burkett LN, Ball SD. A meta-analysis to determine the dose response for strength development. Med Sci Sports Exerc. 2003 Mar;35(3):456-64.