Today I bring to you some application principles on how to utilise blood flow restriction (BFR) training in your programming and also some brief information on what BFR is, why BFR is a great addition, any concerns of BFR and finally how to actually apply it.
If you haven't read my BFR theory article yet, I recommend doing that here first. Leeeeezzz go!
What is BFR?
BFR refers to a training technique whereby a cuff, tourniquet or even something as simple as a knee wrap is used to wrap the proximal end of a joint at a moderate to high intensity in order to restrict venous blood flow out of the muscle. The goal is not to prevent arterial blood flow but instead, solely restrict venous return blood flow causing a localised pooling of blood in the target muscle.
The primary muscles that can be subjected to BFR training are:
Biceps - Wrapped above the deltoid (coracoid process) or at the top of the arm where the deltoid inserts into the humerus
Triceps - Wrapped above the deltoid (coracoid process) or at the top of the arm where the deltoid inserts into the humerus
Forearms - Wrapped just below the elbow
Knee extensors (quadriceps) - Wrapped at a 45-degree angle at the proximal hip joint through the groin region
Knee flexors (hamstrings) - Wrapped at a 45-degree angle at the proximal hip joint through the groin region
Calves - Wrapped just below the knee joint
Is BFR better?
No, it’s not. The primary determinants for hypertrophy (volume/intensity/frequency) do not change and at this stage have not been trumped by any other training methodology, however, BFR is certainly, like many other modalities, a great supplemental way to support your dominant training programming.
In essence, based on the current research available, BFR offers the same hypertrophy benefits as normative training without the risk of injury or overtraining as you train at a much lower intensity (20-30% of 1RM). This makes it a great addition to de-load phases, during times of injury or even just a simple program switch to minimise the risk of injury due to a reduction in intensity.
How does BFR work?
If you’re familiar with my writing you will know I consistently refer to the two types of muscle growth, of which are myofibrillar (increase in muscle tissue) and sarcoplasmic (increase in muscle content). Traditionally when we look at lower intensity sets focusing on metabolic stress through lactic acid accumulation etc, the primary hypertrophy you experience is sarcoplasmic.
However, the awesome thing about BFR is that despite its affinity to low intensity training, its primary function of hypertrophy is through the activation of type 2 muscle fibres (fast twitch), which are traditionally only recruited under maximal load for maximal effort once slow twitch fibres are fatigued. Which is exactly what happens with BFR, however, due to the metabolic demand of the high rep nature of BFR sets, slow twitch fibres are fatigued quicker meaning a greater stimulation of type 2 fibres and those are the fibres with the greatest growth potential.
Secondly, BFR training has also been shown to stimulate muscle protein synthesis through mTor signalling and may even reduce the activity of myostatin locally, which is a circulating protein responsible for the prevention of muscle growth.
BFR training essentially achieves all of the major positive benefits of traditional higher rep percentage training in causing mechanical myofibrillar growth responses but also shows tremendous promise in inducing metabolic stress as well leading to a greater overall muscle protein synthesis response.
Contra-indications (potential concerns)
Now I know it sounds all good to be true and therefore you should swap out all other training modalities for BFR, however, I would not recommend doing that. While BFR has grown in its support via both scientific and applicative literature, I would still like to see some more studies implemented in younger populations looking at its effects on Blood Pressure (BP), Heart Rate (HR), Muscle Stress Indicators (MSI) and Whole Body Lactic Acid Accumulation (WBLAA) during an extended study using it to its maximum capacity.
While the current studies on the above indicate there are little concerns, some have shown increases above baseline in HR, BP and WBLAA. These are only precautionary concerns, however, BFR needs to be used with precaution and as always may be worth referencing some important cross testing with your health care practitioner.
So let's get to implementation:
Phase 1 – When can you use BFR
My top 3 recommendations on when BFR can best be used to maximise hypertrophy:
- If injury limits your ability to train heavy, swap 1-2 exercises for BFR at the end of a workout and keep the rest of your session volume based. This is a great way to overload the muscle without the presence of true mechanical load and with low injury risk
- During a de-load phase. This allows you to maintain growth stimulus without affecting the benefits of your reduced volume or intensity week
- As a 2nd or 3rd session option for high-frequency training to minimise joint stress. This allows you to overload smaller muscle groups like arms that can't handle high frequency and high volume at once due to a high risk of tendon inflammation and joint pain.
I find doing BFR at the end of a big compound week is a great way to still get hypertrophy gains without the joint and tendon pain from heavy isolation work.
Finally, you can also utilise BFR for injury recovery as some studies indicate benefits in reducing expected muscular atrophy in an immobilised limb, however, it is best to discuss this with your physiotherapist as tourniquet pressure is of critical importance given the current research on BFR for rehabilitation is limited.
Phase 2 – How to apply BFR
1) Wrap style
First let's discuss tourniquet tightness, as this is extremely important and can impact your ability to complete the sets drastically as well as increase the risk of any adverse reactions occurring like increased BP and HR etc.
The easiest way to determine tightness is to scale your tightness on a 1-10 level, however it will take time for you to find your groove on this one but aim for a 7 in general for all muscle groups. Larger muscles like the legs can generally take a little more and conversely smaller muscles handle less but aim for about 70% tightness as this will cause venous restriction as intended without arterial restriction, which if that were to occur your performance would be negatively effected and therefore so would your hypertrophy.
Secondly, the tourniquet width itself is important too. Aim for a tourniquet that is approximately 2-3 inches in width for the smaller muscle groups and 3-4 inches for your thighs, which you could easily just use knee wraps for if they have high elasticity.
There are two things to consider with BFR timing and that is the number of reps you should aim for as well as the total amount of sets.
Please note that the tourniquet should remain on for the entire BFR set. Removing the wrap and allowing return venous flow during a BFR set will completely mitigate the proposed benefits.
Aim for 20-30% of your 1RM for a given exercise and focus on isolation style movements like bicep curls, tricep push downs, leg extensions/curls and calf raises. You can use compounds as well if you wish, however my preference is to save these for standard volume/intensity progressions.
Your sets should look something like this:
- Set 1: 30 reps
- 30 seconds rest
- Set 2: 15 reps
- 30 seconds rest
- Set 3: 15 reps
- 30 seconds rest
- Set 4: 10-15 reps
Most will find in set 4 your ability to maintain performance is drastically reduced, however, if you can maintain performance a 5th set is optional, however, 4 will usually get the job done.
Choose a weight that should have you failing at around 10-12 reps in your 4th set.
Only once the 4 sets are completed can you then remove the tourniquet.
BFR is hands down one of the most painful training modalities you will experience. Use it sparingly and be smart with your exercise prescription to minimise the risk for any unnecessary injuries.
People will look at you weird but that’s ok… my partner once said to me “when you see someone do something weird in a gym you always know they are either completely cuckoo or know something you don’t and are smart.”
Moral of the story… don’t worry about what other people think of you, enjoy the pain and embrace the gains!