What in the world is Blood Flow Restriction therapy?

Blood flow Restriction therapy uses either an elastic band or pneumatic cuff to restrict blood flow of a muscle group or limb while during exercise. The purpose of the cuff or band is to block or occlude arterial or venous blood flow from the targeted area, while being able to exercise with a significant decrease in weight or load. The restriction of blood flow to the muscle is done strategically to increase metabolic stress on a muscle group while using lighter weight or resistance. Metabolic stress builds muscle, strength and endurance.

BFR is often used to rehab a musculoskeletal injury where injured tissue requires a moderate to heavier load or stimulus to change, but the injured tissue is often unable to withstand a load large enough to create the required change. 

Many rehab programs use a theraband to add mild loads on joints or muscles, but therabands alone may not provide enough load to achieve the appropriate stimulus. This is where the use of blood flow restriction therapy shines. 

This is a method that seems to be new, but has actually been around since the 1960’s. Blood Flow Restriction Therapy was developed in Japan and is also known as KAATSU training, which means “additional pressure” in Japanese. Since then, BFRT has gained popularity worldwide, particularly among athletes, military personnel, and individuals who are recovering from injuries or surgeries.

Without getting too deep into muscle physiology during exercise we need to describe what happens so you see the need to use Blood Flow Restriction Therapy. In general while exercising muscles have access to oxygen because of normal blood flow in the area. This oxygen is used in the surrounding tissue while under exercise to help provide ATP which is energy for the muscles to contract. This process happens all day long and increases as intensity increases. 

A major reason why blood flow restriction therapy has a positive outcome of muscular size and strength is because of the metabolic response from this training. As there is less oxygen used for muscular contraction, a metabolic byproduct of lactate is seen to increase. Lactate increases along with Insulin Growth Factor help to increase muscle size.

The underlying principle of BFRT is that by restricting blood flow to a muscle, you can reduce the amount of oxygen and nutrients that are delivered to the muscle, which leads to a buildup of metabolic waste products such as lactic acid. This, in turn, triggers a number of physiological responses that can promote muscle growth and strength.

When performing Blood Flow Restriction Therapy the cuff or band is placed around the upper portion of the limb (ei: arms or legs). The cuff or band is then inflated to a pressure that is slightly higher than the systolic blood pressure (the highest pressure in the arteries during a heartbeat) and left in place for a period of time, usually between 10 and 30 minutes. During this time, the individual performs a series of low-intensity exercises such as lifting light weights, using bands, or performing bodyweight exercises.

This can be especially beneficial for individuals who are unable to tolerate high levels of stress on their joints such or who are recovering from an injury or surgery.

A deeper dive into the benefits show that BFR can:

  • Increases production of anabolic hormones such as growth hormone and insulin-like growth factor-1 (IGF-1), which promote muscle growth.
  • Increased recruitment of type II muscle fibers, which are responsible for explosive movements and high-intensity exercise.
  • Increased muscle protein synthesis, which is the process by which muscle tissue is built and repaired.
  • Increased blood flow to the muscle, which can improve the delivery of nutrients and oxygen.

BFRT has been shown to be effective in a variety of populations, including older adults, individuals with osteoarthritis, and individuals who are recovering from anterior cruciate ligament (ACL) surgery. It can also be used to enhance athletic performance and improve muscle strength and endurance in healthy individuals.

While this modality seems like a miracle cure there of course are certain reasons why this would not be for everyone. Known contradictions for BFR training includes:

  • Acidosis
  • Cancer
  • Extremities with dialysis port
  • Excessive swelling in port surgical limb
  • Lymphedema
  • Infection
  • Increased intracranial pressure
  • Impaired circulation
  • Open wound or fracture
  • Pregnancy
  • Previous revascularization of limb
  • Hormone replacement therapy

Aside from contradictions, just like most procedures, there are some risks involved.  Risks may include:

  • Blood clots
  • Nerve damage
  • Muscle damage
  • Rhabdomyolysis, a condition in which muscle fibers break down and release their contents into the bloodstream, which can lead to kidney damage.

It is important to note that BFRT should only be performed under the guidance of a qualified healthcare professional, such as a physical therapist or athletic trainer. These professionals can ensure that the cuff or band is properly applied and that the individual is using the correct amount of weight or resistance during exercise.


  1. “Blood Flow Restriction Training: Implementation into Clinical Practice,” published in the International Journal of Sports Physical Therapy in 2020, provides an overview of the benefits of blood flow restriction therapy, including improved muscle strength and size, and reduced muscle damage and soreness.
  2. “Blood Flow Restriction Training: Evidence, Devices, and Regulations,” published in the Journal of Orthopaedic & Sports Physical Therapy in 2019, discusses the use of blood flow restriction therapy in both clinical and athletic settings, including guidelines for safe and effective implementation.
  3. “Blood Flow Restriction Training: A Review of the Literature,” published in the International Journal of Exercise Science in 2018, provides a comprehensive review of the existing research on blood flow restriction therapy, including its effects on muscle strength, endurance, and hypertrophy.
  4. “Blood Flow Restriction Training: A Mechanistic Overview,” published in the Journal of Science and Medicine in Sport in 2017, explores the physiological mechanisms behind the benefits of blood flow restriction therapy, including increased protein synthesis and growth hormone production.
  5. “Blood Flow Restriction Exercise: Considerations of Methodology, Application, and Safety,” published in Frontiers in Physiology in 2019, provides a detailed discussion of the practical aspects of blood flow restriction therapy, including appropriate cuff pressure, exercise selection, and safety considerations.