5 Things to Know About Blood Flow Restriction Training

Blood flow restriction training, or BFRT, is an exercise training approach that promotes muscle strength and growth using lighter than conventional weight loads. It manipulates oxygen flow to the working muscles to optimize recruitment of Type II fast twitch muscle fiber.

The goal of BFRT is to create the optimal environment for muscle growth without causing breakdown of muscle tissue. BFRT provides a means of rehabilitating injured muscle tissue without overloading damaged tissues and bony structures.

Conventional workloads for muscle hypertrophy and strength are typically calculated at around 70 percent of one-rep max (1RM), while BFRT uses workloads as low as 20-30 percent 1RM. For example, if a healthy athlete can perform a biceps curl one time with a maximum load of 70 pounds, their conventional training load would be 70 x 0.70, or about 50 pounds. With BFRT, the training load for the same athlete with an injury would be 70 x 0.20, or about 15 pounds — a big difference!

During a BFRT session, special occlusion bands are applied to the patient’s upper thigh or upper arm, depending on the exercise. The bands are similar to a blood pressure cuff, and occlusion is measured in a similar way. The idea is to apply enough pressure to restrict, but not entirely cut off, blood flow to the working muscles.

Once the cuff is in place and inflated to the appropriate occlusion level, the patient exercises in the same way as in any traditional training program, but at a lower resistance. Typically, three sets of multiple repetitions are performed to volitional fatigue, with a 30-second rest between sets.

Whenever an unconventional treatment approach gains traction, it is not uncommon for critics and skeptics to emerge from the woodwork. In the case of BFRT, there are a few common misconceptions about the method:

1. Misconception: BFRT is only safe for athletes and bodybuilders.
   Fact: A growing body of research indicates that BFRT has applications in a wide variety of clinical cases, including post surgery, osteoarthritis treatment, and strengthening of deconditioned patients.
2. Misconception: Practitioners of BFRT need a special certification.
   Fact: While there are certification programs available through device manufacturers, a qualified therapist who understands the science underlying BFRT does not need to obtain a special certification.
3. Misconception: To be effective, BFRT requires a complicated exercise program.
   Fact: BFRT is effective using traditional exercises that are common in basic workout programs. The important thing is to monitor speed, range of motion and intensity, to ensure a training effect occurs.
4. Misconception: To legally practice BFRT, the therapist must use an FDA-approved occlusion device.
   Fact: BFRT devices are relatively simple, and are considered low risk by the FDA. Devices sold on the market do not need the agency’s approval, although some manufacturers may use FDA approval as a marketing tactic.
5. Misconception: The higher the occlusion pressure, the greater the effect.
   Fact: Applying too much pressure can cause tissue damage, yeilding the opposite of the desired effect. The goal of occlusion is to restrict venous blood return. Since veins are closer to the skin’s surface than arteries or nerves, moderate pressure occludes veins without hampering the function of nerves or arteries. Too much pressure can cause damage to those structures.

It is important to note that every patient is different, and pressure and training loads should be personalized to meet individual needs. Doppler ultrasound is the best tool for determining individual limb occlusion pressure.