Is cutting off blood circulation REALLY an effective way to build muscle? Yes, the pump is insane...But what’s really going on INSIDE the body when we use this technique? Because that’s all it really is, right? “Blood Flow Restriction” (BFR) Training or “Occlusion Training” is a technique that helps you increase the intensity of your workouts, just like drop sets or supersets, by increasing the amount of metabolic stress we induce in a single working set. Well, today we’re going to take a closer look at BFR training to see what the science has to say about whether or not you can build more muscle and strength with this technique when compared to traditional training.

But even if it can, is this even safe? You’re basically using a tourniquet to trap blood in an area you’re trying to train. Well, it should go without saying that you should first consult your physician to ensure you don’t have any pre-existing blood pressure complications before trying this technique and even though I’m sure I could easily find “before and after” photos and testimonials swearing that BFR training works wonders, in today’s article, we’re going to let the science do the talking.

Blood Flow Restriction Training – What Is It Exactly?

As I briefly mentioned already it is a technique to increase the intensity of your working sets where you will be able to in theory build the same amount or just as much muscle training with lighter weight, compared to traditional weight training. But this doesn’t REPLACE heavy lifting, it’s just a technique.

For example, we all know that in order to achieve muscle hypertrophy or muscle gains, our working sets should be around 8 – 10 reps using less than 80% of your 1RM. But the majority of BFR exercise and training uses lower intensity, closer to 20 – 40% your 1RM and closer to 15 – 30 reps per set.

But before we get to any conclusive evidence, I think we need to first talk about blood circulation so you can 100% grasp the concept BFR is built upon. You see, the human body circulates blood in two ways; The first is when blood is pumped out of the heart and into the muscles and organs via the arteries. The arteries then carry this “clean”, oxygenated blood wherever it needs to go. That’s why arteries appear red. But you can’t REALLY see them because they’re buried deep underneath the skin and for good reason.  Arteries are characterized by “high” blood pressure, which is why slicing them open is generally NOT A GOOD THING to do!  I’m sure you’ve all seen war movies where a soldier gets critically injured and blood just start spurting out everywhere. Well, that’s a severed artery and that’s why they’re buried deep. But VEINS are a different story.

Veins carry deoxygenated blood or “venous blood” from the muscles and organs back to the heart & lungs. Also, the pressure in your veins is quite low and the reason the blood can appear blue is because this blood is filled with metabolic sewage, including toxins and other garbage! But don’t worry, this venous blood will go back to the lungs to become re-oxygenated and then to the heart where it will be re-pumped into your body and the cycle continues!

So once more:

• Arteries = clean blood that travels INTO the muscles
• Veins = deoxygenated blood that travels OUT OF the muscles

How Does This Relate To BFR Training?

You see, BFR Training involves using a band to cut off VENOUS blood flow (or the flow of blood from veins returning deoxygenated blood back to your heart) while maintaining arterial blood flow into the muscle. Are you with me so far?

OK good, nowhere is the theory as to why this is effective when building muscle.  By cutting off the venous blood flow, this will lead to metabolite build-up within that particular muscle, or in this case the BICEPS.  Also, just to recap, metabolites are the substances (generally waste products) produced as a result of muscular contraction.

Now, normally what happens is that blood is able to flow into the muscle during training and as metabolites build up, they are carried away once your set is over allowing the muscle to recover from fatigue and one metabolite in particular, inorganic phosphate, which increases during your set due to breakdown of creatine phosphate, appears to be a major cause of muscle fatigue. 

This is why creatine is often used by athletes that train with a lot of intensity.  The stored creatine phosphate in the skeletal muscle helps resynthesize ADP back into ATP.  But that’s a video for another day.

However, with blood flow restriction training, because these metabolites can’t escape the muscle once the set is over, the result is MORE metabolic stress on the muscle during the next 3 – 4 sets, which in theory SHOULD lead to faster training adaptations and thus MORE MUSCLE GAINS!

Also, because you are only restricting venous blood flow and not arterial, this method is safe.  In fact, if you take a look at this study it’s been proven that “With heavy resistance training (or 80-100 percent your 1RM), mean arterial blood pressure has been shown to more than double, with heart rates reaching maximal levels. However, research on low-intensity BFR shows an increase in blood pressure and heart rate by only 11-13 percent. As such, traditional resistance exercise results in much greater blood pressure, heart rate, and even cardiac-output changes than low-intensity BFR Training.”

Just make sure you don’t crank the bands too tight.  I would say on a scale of 1 – 10, bring them to about a 6 to 7 and it’s better to be a little too loose than too tight. So it’s “safe”, but how do we prove that BFR Training actually works to help build more muscle?

What The Science Says About BFR Training

Let’s examine this study right here from MASSMEMBER.com. Two groups of powerlifters trained FRONT SQUATS for 6 and a half weeks. The group doing front squats with blood flow restriction used approximately 24% of their 1RM for week 1, and approximately 31% of their 1RM for week 3 and they performed four sets with 30 seconds rest between sets in each low-load BFR session, with the first and last sets taken to voluntary failure and rep targets of 15 and 12 reps for sets 2 and 3 and the BFR wraps remained on between sets.

The group doing heavier front squats performed 6 – 7 sets of 1 – 6 reps with 60 – 85% of their 1RM. Details of each session weren’t provided, but the training programs were designed by the national team coaches and were part of the lifters’ annual periodized plan. Overall, this group performed more sets of front squats in each session, but it doesn’t seem that they were taking any sets to failure.

What was the overall result?  In the group performing blood flow restriction training, type I or “slow-twitch” muscle fibers increased in size by roughly 12%, while type II or “fast-twitch” muscle fibers didn’t grow, which provided clear evidence of fiber type-specific hypertrophy, while the group performing traditional, heavier training failed to grow.

Also, this is super important, the group training with BFR had an increase in myonuclei in their type I muscle fibers as well!

So is this conclusive evidence that BFR Training is KING when it comes to muscle growth?  Well, I don’t think we should jump to that conclusion quite yet. If you remember, in my Nuclei Overload video I talked about our “natural potential” as athletes and that maybe our current plateaus are due to the fact that we have exhausted what’s capable in terms of muscle GAINS with our traditional ways of thinking about training.  To me, this study shows a group of powerlifters basically switching from heavy sets of 1 – 6 reps to NUCLEI OVERLOAD TRAINING (NOT) for 6 weeks.

When you think about it that way, I think it’s fascinating that a study was able to prove without trying that NOT can be effective even in seasoned powerlifters and that muscle gains gain be achieved with even just 24% of your 1RM! And if we take a look back at this study from 2012, this chart concludes that various other studies on BFR Training have proven that this technique also increases Growth Hormone as well. So by now, I am positive quite a few of you are looking to try BFR Training, so let me leave you with a few more tips and how to get started.

How To Implement BFR Training

Again, first, check with your physician for any pre-existing blood pressure complications because you can never be too careful.  Then, pick which body part you want to try this on.  I’m sure the majority of you will go for your arms and if that is the case always wrap just above the biceps. But if you want to train legs, always wrap your upper thigh, just below your hip.

As for how often, sets and reps, in an article by “Dr. Jacob Wilson” he recommended that you only utilize this method 1 – 3 times a week and complete 4 sets with 30 reps on set 1 follower by 3 sets of 15 reps with 30 seconds of rest between sets, using 20-40 percent of your one-rep max. Now Dr. Wilson also recommends that you use BFR Training as a finisher and on isolation type movements. I would suggest starting there as well. For example, if you were training back and biceps, I would still perform my heavy working sets, but finish the overall workout with BFR training on a curl type movement.

Also, I did try BFR training for a few weeks and I want to add my own input here as well.  Number one, you’re going to feel like your arms are going to explode and you need to FIGHT THE URGE to remove the bands. You have to leave it on for all 4 sets!  Number two, you’re going to be VERY vascular during your sets. That’s because BFR training increases vasodilation which is when the blood vessels expand for greater blood flow and as a result decrease blood pressure and increase your overall vascularity while exercising.

Another thing to note is that the first set is going to feel super easy, that’s why you’ll be able to complete 30 reps. Set 2…not so much because that’s the point of the blood flow restriction. We are increasing metabolic stress by preventing the venous blood from leaving the area! And lastly, it’s a lot easier to find the right amount of pressure when wrapping your arms versus your legs, so don’t be surprised if you need to readjust a few times when wrapping them.

Conclusion

One last thing I thought was really interesting that Dr. Wilson mentioned in his article was that “because BFR causes very little muscle damage, it can be used during deloading periods to supplement as much as 60 percent of the high-intensity workload. That way athletes can continue to progress while allowing their joints and/or injuries to heal.” So if you are due for a deload week, this could be right up your ally!