What is BFR?
Blood flow restriction, also known as occlusion training, is a distinctive training method that looks dangerous but has thousands of research articles supporting its safety and use in the practical setting (1). It allows you to train at low intensity (weight) with high reps and still achieve similar strength training benefits to heavy resistance training (1).
In the practical setting, blood flow restriction requires a lifter to apply a band or straps at the most proximal location of a muscle, i.e. the top of the biceps, at an 8/10 rate of perceived. So why 8 and not 10? The idea of BFR is not to restrict blood from entering the muscle but stopping it from leaving (1).
As you perform an exercise with BFR you would experience an influx of arterial blood flow into the muscle with a restriction of venous blood flow return (1). In simpler terms, this means blood will enter and be trapped in the muscle for the course of the exercise.
When you reach higher reps, you will experience a burning sensation known as lactate (1). Lactate creates an acidic environment that is suitable for the release of growth factors, which pool in the blood, providing a cellular response to the muscle and acute cell swelling (1). In other words, you are gaining muscle strength and size without the heavy lifting.
Not to mention, with BFR training, there is a lack of oxygen in the muscle, which rapidly fatigues the slow and medium twitch muscle fibers and activates the fast-twitch muscle, which in normal circumstances would only be achieved by heavy lifting (1).
BFR can also be combined with other compound lifts like the bench press or back row, preferably at the end of a training session which may pre-fatigue the secondary muscles i.e. bicep and triceps, thereby creating more tension on the prime mover muscle group (1, 2).
How to use BFR (4 step guide)
Below I have highlighted a step-by-step guide to performing BFR bicep curls, but remember that BFR can be applied to any muscle on both upper and lower extremities, including muscles on the legs and arms.
Step 1: Get a pair of leg straps or occlusion straps; I prefer cuffed leg straps as I feel they occlude the blood flow a lot better.
Step 2: Place the upper side of the biceps into cuffs and wrap the bands symmetrically around the arm at a 7-8 rate of perceived effort.
Step 3: Pick up an EZ curling bar that represents 30-40% of your 1RM (1 Repetition Maximum) intensity, so if you can bicep curl 88lbs, during BFR you could apply a total weight of 26-35lbs.
Step 4: Perform 4 sets of bicep curls with 30 seconds rest intervals in between. A bicep curl exercise would be as followed;
Set 1: 25-30 reps
Set 2:15-20 reps
Set 3: 15-20 reps
Set 4: 15-20 reps
What does the Research say about BFR?
From the information above, you may think that BFR can only benefit the limb that it is applied to, but in fact, Yamanaka et al. (2) compared BFR Applied vs No BFR muscles in male college athletes during their off season.
The participants performed the bench press and squat at a 20% intensity with an initial 30 reps and 3 sets of 20 reps after their regular offseason training. These exercises were performed 3 times per week.
The BFR condition provided more benefits compared to the no BFR condition, which I have highlighted bellow.
Bench press: +21lb vs. +9lbs
Squat: +31.1lbs vs.+16lbs
Upper chest size: +3.8cm vs. +1cm
Lower chest size: +3.1cm vs. +1.2cm
Right Thigh: +1.2cm vs. 0.7cm
Left Thigh: +1.1cm vs. 0.6cm
Who Should Use BFR?
#1 Injured Athletes and lifters
Skeletal injuries can hinder mobility and disallow lifters to perform heavy lifts, not to mention that heavy lifting is risky as it may cause the injury to reoccur (1).
For example, if a lifter has a bicep strain, they could opt to use BFR at a low intensity of 20%, which is not likely to hinder the rehabilitation process.
#2 Older Adults
If you have been following my previous articles, you must be well aware that in our older ages, we experience natural declines in physiological functions like; muscle, bones, tendon, and ligament strength (1).
It's common for older adults not to possess the physical capabilities to perform moderate-high intensity resistance training, which is crucial to counteract the natural declines with age (1).
BFR can be used by older adults at a low intensity and still achieve the same results as they would if they lifted heavy weights (1).
#3 Lifters during de-load phases
The idea of a de-load is to reduce the intensity to allow the body and central nervous system to recuperate from all the heavy lifting that takes place during strength-based programs (1).
For this reason, BFR is a great intervention as we have established that it utilizes very low intensities (1).
I would not replace conventional resistance training with BFR, but use it as a tool when you cannot and do not want to lift heavy; this can be for the injured, elderly, and de-loading lifter.
Moreover, BFR should not be limited just to training the limbs. Research has shown that BFR combined with low-intensity bench press and squat may help increase the muscle girth and strength of the upper and lower chest, legs, bench press, and squat as one rep maximum.
- Hwang, P.S., & Willoughby. Mechanisms Behind Blood Flow–Restricted Training and its Effect Toward Muscle Growth. Journal of Strength and Conditioning Research. 2019; 33(1): S167-S179
- Yamanaka, T., Farley, R.S., Caputo, J.S. Occlusion Training Increases Muscular Strength in Division IA Football Players. The Journal of Strength and Conditioning research. 2012; 9 (6): 2523-2529