Is Blood Flow Restriction Training Safe?

What is Blood Flow restriction Training (BFRT)?

Blood flow restriction training is a technique that can be used to perform exercises with a reduced amount of blood flow to the arm or leg.  This is often achieved by using a cuff or strap placed tightly around the limb to reduce, but not wholly occlude, blood flow.  The benefit of blood flow restriction training is to allow the person to exercise with lower intensity but still have the help of high-intensity training.

Blood flow restriction training has emerged in the fitness and rehab worlds as the latest modality to help patients get their strength and muscle mass back faster than ever. Much research has shown that hypertrophy (muscle mass) gains can be achieved at very low loads (20-30% of an individual’s one-rep max) versus conventional training requiring loads at 75% or more.

Can Blood Flow Restriction Therapy Help You?

The answer is yes.  There are beneficial implications in the rehabilitation world.  BFRT can help us get patients stronger without loading injured muscles, tendons, ligaments, and joints to the point where we further damage the tissues.

For the sports performance world, creating muscle strength & hypertrophy at low loads without the breakdown of muscle proteins also makes it a possible addition to training programs.

I’ve reviewed this research previously in the following articles. Still, today, we’ll focus on the question of “Is Blood Flow Restriction Training Safe?” as there are several dangerous myths around the use of BFR.

Blood Flow Restriction Training – What Trainers Need to Know

Does BFR Cause Blood Clots?

This is an obvious concern with the implementation of BFR. Does placing a tourniquet and restricting blood flow increase-clotting risk?
Fortunately, several studies have examined these questions and support that BFR does not increase clot risk. Blood flow restriction and heavy resistance training are associated with releasing several anti-coagulation factors (Jarrett 2004). Studies have shown no increases in clots when BFR training programs are implemented (Hylden 2014).

Is Blood Flow Restriction Safe on the Cardiovascular System?

This is the second concern with the use of BFR. Are we potentially damaging the heart and blood vessels with BFR?

Let’s start with the incredible amount of stress that heavy resistance training places on the body. During high-intensity training, blood pressure values as high as 480/350mmHG during heavy lifting (80%1RM) and 255/190mmHG during simple bicep curls are seen (McDougal 1985)! And heart rates have been shown to reach 170BPM.

In contrast, while BFR training does increase both of these markers, research has shown blood pressure readings to only increase to 180/100mmHG and heart rate values to 110BPM (Takano 2005). Both are considerably lower than that seen with heavy resistance training.

Other research has shown either no change or improvements in arterial compliance and stiffness with BFR (Kim 2009, Fahs 2011, Ozaki 2013, Ozaki 2011). Hunt (2013) found improvements of 14% in capillarity vs no changes in work matched controls.

THE BIGGEST RISK FACTORS

The biggest risk factors come from a few variables: improper tourniquet width, too much tourniquet pressure, and improper placement of the tourniquet.

First up we’ll tackle tourniquet width, which has been improperly interpreted by many in the fitness world. BFR works through the partial occlusion of blood flow. According to multiple research studies, WIDER CUFFS DECREASE THE PRESSURE NEEDED TO RESTRICT BLOOD FLOW. This means that the small cuffs sold by many “BFR” manufacturers increase the risk of soft tissue damage. It would help if you used a wider tourniquet to minimize this.

The next risk factor is too much pressure, which has already been partially covered. In the BFR certification courses I teach, we discuss LIMB OCCLUSION PRESSURE, the MINIMAL amount of force needed by a specific patient, in a particular limb, on a specific day, needed to impede the proper amount of blood flow.

Think of this as working hard for the same amount of money…you’d NEVER do that, right? So we only want to use the minimum amount of pressure necessary to make our strength & hypertrophy goals happen.

TOP RECOMMENDED PERSONALIZED BLOOD FLOW RESTRICTION SYSTEM

This is where the Delphi PTS system comes in for medical professionals.  This system takes care of most safety concerns with BFRT and is the only device approved by the FDA for use on patients.

Finally, the placement of the BFR device is critical. There are only two places where a BFR device should be placed. That is the upper arm and upper thigh. This will minimize the risk of nerve damage. Tourniquets in other areas have been known to cause nerve damage issues, including nerve palsies such as drop foot.

Contraindications

Several contraindications of BFRT training should also be observed.  Would you please review the table below.

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