Wrapping your arms up and doing bicep curls may seem like a gimmick to increase vascularity and impress other gym goers. As it turns out though, there is actually quite a bit of science behind this technique indicating that it could very well be a worthwhile addition to a well balanced resistance-training protocol. If used correctly, practical blood flow restriction training (BFR) could help you bust through hypertrophy plateaus, pack on additional mass and even aid in growth or maintenance of muscle mass during times in which lifting heavy weight is either impossible or ill-advised.
Chances are if you’ve ever noticed somebody in the gym with their arms wrapped up with either knee wraps or a make-shift tourniquet, they were practicing a style of training popularized by Dr. Yoshiaki Sato known as ‘Kaatsu Training’ or more commonly known as ‘Blood Flow Restriction training.’
Blood Flow Restriction training (BFR) is a style of resistance training that utilizes the practice of wrapping a form of a tourniquet around a limb and training with a relatively light load. It’s a practice that has gained quite a bit of traction in the resistance training science realm over the past few years and is something that may benefit your training protocol if used correctly. However, before we get into how to use it, let’s understand what is actually happening in the body when you use it.
The Science Of Blood Flow Restriction
As such, the purpose of using some form of a tourniquet is to inhibit the ‘venous return’ of blood to the heart while still allowing arterial blood flow into the muscle. By doing this, the blood continues to be shuttled to the muscle and pools without being able to escape.
As mentioned prior, BFR requires the use of some form of a tourniquet around a limb in order to inhibit blood flow. However, not all blood flow is in fact restricted. The purpose of the tourniquet is to prevent what is called ‘venous return’ of blood to the heart. When you contract a muscle, more blood than normal is shuttled towards the muscle in use via arteries to provide a myriad of different nutrients to the muscle, such as oxygen. Typically if ‘un-wrapped,’ the blood then returns to the heart via veins in order to rid the muscle of metabolic by-products such as carbon dioxide, lactate, and hydrogen ions (the acid that makes your muscle “burn”).
The purpose of using some form of a tourniquet is to inhibit the ‘venous return’ of blood to the heart while still allowing arterial blood flow into the muscle. By doing this, the blood continues to be shuttled to the muscle and pools without being able to escape. It is thought that the accumulation of blood and bi-products leads to activation of fast-twitch muscle fibers, which is typically thought to only occur after going to failure or utilizing fairly heavy loads. By doing this, you increase the potential for your muscle to grow.
For starters, the research seems to indicate that you can complete significantly less work in order to achieve the same results.
So why in the world would wrapping your limbs be a good idea for resistance training? As it turns out, the use of BFR training provides similar benefit in terms of muscular reaction to training as heavy resistance training or lower load resistance training taken to failure (1,2). In addition, BFR seems to afford you this benefit while allowing you to use very light loads (roughly 40% of your 1 RM) and with far fewer repetitions than had you used the same weight without wrapping your limbs. In fact, a recent study by Farup et al., in 2015 indicated that when participants used the same load (40% of 1 RM) and either used a tourniquet or did not, the group using BFR observed the same increases in strength and muscle volume as the group which did not. The catch: the BFR group had completed significantly fewer repetitions, and thus less total volume, in addition to less time under tension. This means they observed the same benefit but achieved in significantly less time.
You may be asking why you would ever need to utilize this style of training. For starters, the research seems to indicate that you can complete significantly less work in order to achieve the same results. Utilizing BFR training is perfect for times that you are fatigued or just too sore to perform heavy resistance training or are just in a time crunch. Additionally, using BFR is a prime candidate for times when the use of heavyweight is seemingly impossible or ill-advised such as post-injury or operation, or being elderly.
How To Use Blood Flow Restriction Effectively And Safely
Considering the nature of this style of training, BFR requires the use of some form of a tourniquet. The easiest and most convenient way to achieve this is to use some form of the elastic strap such as an ace bandage or weightlifting knee wraps. If you can find a strap with a similar elasticity, yet smaller width, this would be more optimal. When wrapping your limbs, you want to avoid wrapping ‘over’ the limb being trained. Otherwise, you can risk limiting your range of motion and the muscle’s ability to fully contract.
You’ll want to place the wrap near the ‘proximal portion’ of the muscle you are working. This means above the muscle and close to the torso. For example, if you are planning on training your biceps and forearms, you should place the wrap on the upper portion of your arm above the bicep, and below the deltoid. Using this technique for the lower body has some less certain instructions. Some experts say that when practicing BFR for the lower body, your leg should be wrapped above the quadriceps, near the groin area. This would include if you are training calves. Personally, when training BFR for calves, I choose to wrap just above the calf and below the knee. This is primarily because the wraps I use are simply not large enough to effectively wrap above my quadriceps.
When wrapping your muscle, remember to keep in mind that you are not trying to completely restrict blood flow. You still need blood flow to the muscle. As such, when you wrap, you should try to shoot for wrapping the arm at about a 7 out of 10, with ten being very painful and a complete loss of blood flow. If your arm is totally asleep before you even begin training, the wrap is too tight. If you complete a set and your arm isn’t pumped or fatigued, then you have probably not wrapped tight enough.
When training with this style, you’ll need to keep in mind that you need to approach muscular failure on each set. For each body part being trained, you should aim for completing roughly 4-5 sets, close to failure on each set with minimal amounts of rest in between. A good setup for BFR bicep curls would be as follows:
- Exercise: Machine Preacher Curls
- Weight: 40% of 1 Rm
- Set 1: 30 repetitions
- 20-30 seconds of rest
- Set2: 15 repetitions
- 20-30 seconds of rest
- Set 3: 15 repetitions
- 20-30 seconds of rest
- Set 4: 15 repetitions
- Remove wraps from limbs.
A majority of experts agree that this style of training is, in fact, a safe practice as long as it is executed properly. In order to maintain safety, ensure that you have not completely restricted blood flow.
First and foremost, a majority of experts agree that this style of training is, in fact, a safe practice as long as it is executed properly. In order to maintain safety, ensure that you have not completely restricted blood flow. Further, once you have completed your sets, make sure to remove the wrap immediately in order to provide the muscle with a fresh blood supply and allow the used blood to be recycled. If you keep the wraps on too long or have them too tight, you run the risk of causing cellular and tissue death. This is not advised. Further, if you have existing heart conditions or high blood pressure, using BFR is not suggested.
There is also some evidence to indicate that musculature that is not directly occluded such as chest and shoulders, may experience some benefit from BFR. This is interesting because there was a long withstanding belief that only muscle below the tourniquet would see a benefit. A recent meta-analysis indicated that despite have fairly week evidence, the articles included indicated that indirect muscle (chest and shoulders) may see increased benefit from using BFR in comparison to the same training without a tourniquet. If you feel fatigued, yet still want to get a chest and shoulder pump, it may benefit you to wrap your arms the same way you would if you were training biceps and forearms.
Lastly, BFR should not be used solely in place of other types of training. Outcomes such as strength, power output, hypertrophy and force production rely on training specificity and varying resistance (i.e in order to optimize strength, you need to train with heavier loads for lower repetitions). The research indicates that BFR training may be ‘as good’ as other types of training, not superior. As such, BFR may be a useful tool within a well-rounded resistance-training schedule.
About the Author
Sam is a Certified Strength and Conditioning Specialist (CSCS) and holds a Master’s of Exercise and Nutrition Science from the University of Tampa. Additionally, he holds a B.S. in Behavioral Neuroscience. In his free time, he lifts heavy stuff, loves to run long distances, is an avid video gamer, and recently began his journey to be a big game bow hunter.