If Carlsberg did physical training it would probably involve Blood Flow Restriction (BFR) training…

If Carlsberg did physical training it would probably involve Blood Flow Restriction (BFR) training…probably the best in the world

So how would you feel if I told you there was a way to increase your muscle size and strength without having to lift really heavy weights? And increase your cardiovascular fitness without having to work at high intensity? Interested? Thought you might be! So how is this possible? Well the answer is something called Blood flow restriction training – and it’s probably one of the best kept rehabilitation and fitness secrets. I have been using this technique since 2014 when I first saw it in action at the English Institute of Sport as part of the rehab process. It’s not a fad, nor is it snake oil; it is however grounded in research (a lot of it) used widely in professional sport and could be the thing that gives you the edge or boosts your training to the next level.

So what is BFR?

The main principle of Blood Flow Restriction training is to restrict superficial venous return and the deep arterial flow while exercising at low intensity – typically 20 – 35% of 1Rep max or in zone one for heart rate (we will cover heart rate zone further on – don’t worry too much right now) BFR helps to improve muscular strength, size and functional aerobic capacity more quickly and with less physical stress or load on the body as traditional training methods. It is a safe, effective and portable solution to improve performance, recover from injury or just add to current training routine.

How does it work … Strength and Size.

BFR effectively tricks the brain into thinking one is performing high intensity exercise, the brain and body respond to this with the following effects.

- Increased strength

- Reduced muscle atrophy – important if you are injured or recovering from injury

- Create hypertrophy (muscle growth)

Heavy resistance training generally requires lifting of heavy loads (80-95% of 1RM) and adaptations take between 12-16 weeks to occur for increased muscle mass and 8 weeks for increased muscle strength – this is because the mechanisms by which the adaptations occur require physical albeit minute damage to the muscles – this is the basis of overload training. Now this is great if you have access to an array of gym kit, and are physically able to lift heavy load to force the adaptations to occur. But what if you either don’t have access to or cant physically lift enough load to make the changes? Maybe you have a bad back and cant squat, maybe you are recovering from surgery and are not able to lift anything heavy or maybe you are just don’t feel comfortable lifting weight heavy enough to cause overload.

This is where Blood flow restriction training is perfect. Blood Flow restriction training has been shown to improve strength within 4 weeks, muscle size within 2 weeks and improvements in cardiovascular function with 6 weeks. All while using very low or minimal loads. So this is a fantastic option if you cannot get to the gym ( if, I don’t know, you are like in the middle of a world health pandemic and everything is closed…) to train normally, or cannot tolerate high loads – for example recovering from injury, during an athletic season, to supplement existing training programs or in the elderly. Because you are achieving alterations in the physiology opposed to muscle overload (damage) you gain results faster and can train multiple times per day as there is little recovery required.

The Science bit

This all sounds too good to be true … increased muscle strength, increase muscle size but decreased requirement to lift large loads… how can this be?

Well without jumping back to A Level Biology several things happen – all of these occur at the cellular level – meaning you are working on the cell physiology rather than the muscle structure.

This is simplifying things quite a bit but there is a simple equation for muscle growth

Muscle growth = Muscle protein synthesis – Muscle protein breakdown

If you add more protein than you break down you achieve muscular growth.

As we have already mentioned traditional resistance exercise involves high load, essentially causing damage to the muscle (albeit on small it is damage) this stimulates a series of processes that lead to muscle growth. During BFR – the measures of these processes show that their elevation is minimal – effectively there is NO or very little muscle protein breakdown.

During BFR we are limiting the delivery of oxygen to the working muscle. Which means the recruitment of Type 1 muscles fibers is suppressed as these require oxygen for energy – which we are limiting – which leads to greater recruitment of type 2 muscle fibers. These are bigger. Normally to recruit these we have to work at very high intensity, but because we are controlling or limiting the available oxygen this threshold is lowered.

This leads to an increase in 4 hormones

1. Human growth hormone – up to 170% increase in fact – more on this in a second

2. Increased IGF-1, MTOROC1 and Myostatin.

The 3 hormones mentioned in number 2 means we crease a significant increase in protein synthesis. So we now have more protein synthesis and less protein breakdown which results in a net gain in muscle growth.

The increase in Human growth hormone is also really important as this is what stimulates the synthesis of collagen. Collagen is the most basic building block in the human body – so to effectively recover from injury you need more collagen production – making BFR a fantastic tool for recovery from fractures, surgery as well as tendinopathies to mention just a few.

But the benefits of BFR are not solely limited to increasing muscle size and strength – it has an extraordinary ability to improve cardiovascular fitness or VO2 max. Again working at much lower intensity than would normally be required to bring about such adaptations.

First of all though we need to understand a little about aerobic fitness training and what ‘zones’ we should be working in to improve this and how we go about calculating these zones based off our Heart rate and Heart rate reserve.

Heart rate training zones are worked out by your heart rate reserve – this is your resting hear rate minus your maximal heart rate. Maximal heart rate is widely accepted at 220 minus your age. So for example if you are 35 – you theoretical Max hear rate is 220-35 = 185. If you had a resting heart rate of 65 beats per minute your Heart rate reserve would be 185-65 = 120. This is effectively the ‘cushion of beats’ per minute you have for elevation during exercise.

Traditionally to improve cardiovascular fitness you need to be working in Zone 4 or your aerobic zone (75 – 85% of your heart rate reserve) in this example 75% of 120 = 90 , 85% of 120 = 102 – add your resting heart rate of 65 to both figures and you would need to be working at 155 – 167 beats per minute to be in the aerobic zone. And sustain this for 30 – 60 minutes. This is quite hard work – trust me!

BFR can achieve similar results while working in the ‘low intensity’ zone or zone 1 – this is 20-30% of your heart rate reserve. So using the same example as above 20% of 120 =24, 30% of 120 = 36 add in your resting heart rate of 65 and you get a range of 89 – 101 beat per minute. Significantly easier to obtain than 170 BPM for 60 minutes!

This is a game changer if you are recovering from injury, starting to improve your fitness, want to maintain or improve your fitness without going too hard ‘in season’ or in the older population who its either not a brilliant idea to push that hard or who physically can’t. In this population not only are you improving fitness but you will see the benefits listed in above in relation to strength and muscle size – this will in turn reduce fall risk. Could BFR get any better?

The Science bit

So we all know that when we perform endurance exercise we are working aerobically and when we train for endurance events generally speaking we will do speed sessions and High intensity sessions – the point of these is 2 fold – 1. To increase speed and 2.more importantly to increase our Lactate threshold.

Lactate is a by-product of exercise, once it reaches a certain level (threshold) we start to fatigue. We perform high intensity sessions to produce lactate but more importantly improve the body’s ability to clear it. The more efficient your body is at clearing lactate, the less fatigue you experience and the longer you can exercise for. BFR allows this adaptation to occur more readily due in part to the restriction of oxygen the working muscle becomes incredibly efficient at working with high lactate levels.

But you also need an improved blood pump. Endurance training achieves this by increasing the number of capillaries – a process called Angiogenesis – this is a natural adaptation that occurs with normal training. More capillaries means more blood and therefore more oxygen being delivered to the working muscle, it also means a greater capacity to remove by products such as lactate from the working muscle so that it can work harder for longer, which in turn will mean improvements in VO2 max. BFR allows this process to occur at much lower intensities of exercise than without. It is worth noting that all of the studies so far that have looked at this effect have involved highly trained athletes, to achieve improvements in already highly fit individuals is impressive and it can be presumed that the effect on the lay population will be even more profound.

How to use BFR?

Literally any type of exercise that you would normally perform to improve strength and hypertrophy can be performed with BFR, from body weight to weighted.

Sets and reps we use and most seem to use in the literature is as follows


30 reps , 30 secs – 1 min rest , 15 reps – 30 secs-1 min rest ETC. So 75 reps in total.

What you need –

We highly recommend a set of pneumatic cuffs – these allow accurate occlusion pressures. We use Airbands and sell these in clinic – they are a brilliant system and the only self-assessing, self-inflating cuff on the market. They link via Bluetooth to an app on your phone to accurately record each session.

You can find them on our shop Here.

So in summary BRF is brilliant! You can improve muscle strength and size while lifting low load – which means it’s safe, it can help improve rehabilitation, and improve prehab if waiting for surgery. It also helps in endurance athletes by increasing VO2 Max and increasing Lactate thresholds while training at low intensity. What’s not to love?

Want more info on how BFR can help you maximize your potential – drop me an email and we can arrange a free video call to talk through the options. David@activetherapy.info


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