You might have heard some buzz around Blood Flow Restriction Training (BFRt) over the last couple of years as actors like Chris Hemsworth and NFL teams have been using it to gain muscle and improve performance. Like many training methods out there, the amount of conflicting information is nauseating. In this post, I’ll give an overview of BFRt and try to answer some common questions and dispel some common misunderstandings.
First, let’s do a quick review of how the circulatory system works:
Image by: Freepik
Oxygen is essential for our cells to survive. The circulatory system’s most essential job is to take blood cells that aren’t carrying oxygen, give them oxygen, and then pump them out to the rest of the body. The hungry, oxygen poor blood cells pick up oxygen in the lungs, and then get shipped off to the rest of the body via the left ventricle of the heart.
When the oxygen gets to our muscles, the aerobic (type I) muscle fibers snatch it up and use it to function. These fibers are essential for endurance activities like distance running and cycling.
However, we have some muscle fibers that don’t need as much oxygen to function. These anaerobic fibers are called type IIa and type IIx. These fibers are most responsible for power as with lifting heavy, sprinting, jumping, and other explosive activities.
When we exercise, we use a combination of these muscles to generate force. Depending on the task, some are more active than others.
How Does BFR Work?
Fundamentally, BFRt involves exercising with some degree of restriction of blood flow using an inflatable cuff.
This restriction causes the body to over react to the load applied. The body will perceive an easy exercise as much harder when performed with BFR, which will cause a cascade of events in the body to make muscles grow and increase strength more than they would have without BFR. Here is a flowchart to see the cascade of events that lead to increased strength and muscle hypertrophy:
There is a lot of great research that has come out in the last 10-15 years in support of using BFR for gaining muscle mass and strength as well as some other systemic effects like increasing tendon stiffness and VO2max (a measure of cardiovascular fitness).
So obviously gaining strength is a good thing, but you still have to exercise with BFRt. What makes it better than just exercising normally?
Well, BFRt produces similar strength and hypertrophy gains as traditional heavy resistance training, which is training at or above 70% of your 1 rep max or 1RM (how much weight you can lift once with good mechanics)...
But at low exercise loads.
You can work at 30-50% of your 1RM with BFR and get the same or similar benefits as lifting at 70% of your 1RM. This can be exceedingly helpful for people who can’t lift heavy due to an injury.
What if you ARE able to lift heavy? Is BFRt still helpful?
Of course! BFRt is a great adjunct to any training program, and can help produce good muscular responses without causing the high metabolic stress of lifting heavy. It’s also a good way to focus on specific deficits.
For example, I never quite got my quad strength symmetrical after my ACL reconstruction that I had in college. BFRt is a great finisher to my workouts that provides some extra focused attention to my weaker leg.
Hopefully I’ve convinced you that BFRt is a great tool for gaining strength and overall fitness. Now I’d like to set the record straight on a few misconceptions about BFRt.
Is BFRt a Tourniquet?
No! BFRt is NOT occlusive. If you were on the battlefield and you lost your foot, and someone used a BFR cuff as a tourniquet, you would bleed out. IT IS NOT A TOURNIQUET! It takes a significant amount of pressure to fully occlude the flow of arterial blood (oxygen rich blood coming from the heart), and BFRt does not utilize those types of pressures.
How many cuffs can I put on my body at once?
BFRt is only performed on the arms or legs only, and only up to 2 at a time when performed safely. You may find people on the internet doing more than 2 extremities at a time…I would not recommend that, and neither would the creators of BFRt.
Is BFRt Safe?
Yes! When performed correctly with the guidance of a trained professional, BFRt is very safe, even for elderly folks! There are certain populations of people that are not safe to use BFRt, including some people with circulation or fluid management issues like lymphedema.
Is BFRt Painful?
It shouldn’t be. I wouldn’t call BFRt comfortable, just like I wouldn’t call lifting really heavy weights comfortable. Sometimes you can get some soreness under the cuff, but if I had a client using BFRt and it was really painful, I would change the parameters to make it more comfortable. It is challenging though!
Who are some examples of people that benefit from BFR?
People who are struggling with tendinopathy. Tendinopathy usually causes pain with loading the tendon that is involved, but most rehab protocols for tendinopathy require progressive loading of the tendon (see my last blog post on achilles tendinopathy). BFRt can often decrease hot spots of pain to allow you to tolerate more loading. Additionally, there is some research says that BFRt can increase tendon stiffness (which is a good thing).
People who are struggling with arthritis. Folks in this category often have a hard time lifting heavy weights because it hurts too much either during the workout or after. BFRt can help reduce the overall load on the joints, but still give the muscles a good workout.
People who have muscle loss after an injury or surgery. This is the big one. Anyone who has had an ACL reconstruction or an achilles tendon repair should have BFRt as part of their rehab if it is safe to do so, because the muscle loss in these conditions is so significant, and they can take a while to be cleared to lift heavy.
People training for a running race who need to cross train with non-running cardio activity. If you’re starting to develop an injury that would benefit from less running and less on feet time, biking with BFRt can be a great way to keep your cardiovascular system working while allowing your tissues to heal.
Ready to try BFRt with us at Alterra?
Disclaimer: The information provided in this blog post is for general informational purposes only and is not intended as medical advice.
Sources
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