At the Tokyo Olympics, the new trend is blood flow restriction (BFR) training. The American swimmer Michael Andrew and the American marathon runner Galen Rupp have both been spotted with tourniquet-like bands on their limbs used for BFR, The New York Times reported July 21. RELATED: The Olympic Games Begin! But Under the Cloud of COVID-19 BFR training is a technique in which pressurized bands (which look similar to blood pressure cuffs) are worn around the arms or legs to slow blood flow to specific muscles during training. It’s thought to trigger the body to build more muscle mass than it otherwise would at that training intensity. During BRF training, periods of blood flow restriction are paired with periods of rest during which blood flow is restored to the area, explains Elizabeth C. Gardner, MD, an orthopedic sports medicine surgeon at Yale Medicine and the head team orthopedic surgeon at Yale University Athletics in New Haven, Connecticut. “This allows the involved muscles to reap the benefits of much higher intensity training, while protecting the injured limb from higher stresses.” And while it may be getting more attention thanks to this year’s Olympic Games, the technique itself is not brand-new. Yoshiaki Sato, MD, PhD, is widely credited with developing BRF for muscle training and injury recovery in the 1960s in Japan. He patented his version of the training technique in the 1990s under the brand Kaatsu (now a company that makes its own BRF devices and offers training programs).
What Does the Science Say About Blood Flow Restriction Training?
During BFR training the tight band or strap on the involved limb restricts the blood flow in (which carries oxygen) and out (which carries lactic acid and other waste from muscle activity) below the level of the compression. “This temporarily creates a low oxygen environment for the muscle,” Dr. Gardner explains. It’s this lack of oxygen that forces the muscles to work harder, increasing protein synthesis in the muscle cells, which is important to both muscle repair and growth. Training this way affects the fast-twitch, anaerobic muscle fibers (generally used for explosive activities, such as jumping and sprinting), Gardner says. There’s evidence that BFR training can indeed boost athletic training, and may even help patients with chronic pain or other conditions build muscle more easily, as long as it’s performed correctly. A study published in the Journal of Applied Physiology in December 2019 found that BFR paired with low-intensity resistance exercise yielded similar muscle gains when compared with high-intensity resistance exercise in a group of 55 adult men over a 14-week period. A review article published in October 2020 in Strength and Conditioning Journal concluded that evidence does suggest BFR training can improve muscle growth in athletes, with the caveats that research to date is limited and the mechanism of how it works is not fully understood. But research has also found that many practitioners aren’t properly facilitating the use of BFR with their patients. A study published in 2017 in the British Journal of Sports Medicine, for example, suggested that many rehabilitation professionals were still unclear about how to use it. BFR should be administered by trained healthcare professionals who have undergone a certification course, says Julie Ann Aueron, a physical therapist and doctor of physical therapy with Tru Whole Care in New York City, who has been certified in BFT training by Owens Recovery Science (ORS). Multiple companies, including Kaatsu and ORS, offer BFR certification, she says. And it’s usually physical therapists who pursue this sort of certification and administer the training. RELATED: Post-Workout Muscle Recovery: How to Let Your Muscles Heal and Why
Whom Does BFR Training Work for, and Who Shouldn’t Try It?
According to Steven Munatones, the CEO and cofounder of Kaatsu Global, who is also a Kaatsu master instructor, several Olympic-level athletes have used Kaatsu BFR training, as well as other professional athletes and amateur athletes participating in extreme sports (like ultramarathoners and mountaineers). Andrew has been a Kaatsu user since his teens, when he won his first swimming title, in 2016, according to a blog post from the company. But others beyond top-level athletes stand to benefit from BFR. Gardner explains that it may be an effective technique to build strength and muscle mass in patients with chronic pain who are not able to tolerate higher loads on their body. “Patients with chronic conditions that cause muscle loss, such as HIV/AIDS and COPD, may also benefit, although this must be discussed with the patient’s medical provider in order to prevent complications,” she says. A review published in Frontiers in Physiology in August 2019 concluded that BFR training yielded various benefits to older adults, those at greater risk of falls, and people with kidney disease, musculoskeletal issues, and various types of osteoarthritis. RELATED: The Best and Worst Exercises for Back Pain There are potential risks associated with BFR training if it’s not done properly, says Drew Contreras, a doctor of physical therapy and the vice president of clinician integration and innovation at the American Physical Therapy Association. “If BFR is done without proper equipment and guidance, there can be permanent damage to muscle and blood vessels,” says Contreras. More specifically, improper cuff width, too much restriction pressure on the tourniquet, and improper placement of the cuff can all cause complications, including soft tissue damage, numbness [from nerve injury], and pain, Gardner says. “It is crucial to do this with a trained healthcare professional, like a physical therapist.” Unless you’re young and athletic, it’s a good idea to check with your doctor before trying BFR. Additionally, if you’ve recently undergone surgery, you have an underlying medical condition (particularly ones that can affect baseline blood flow to the extremities, like heart disease or peripheral vascular disease), or you’re an older adult, talk with your doctor before considering BFR training, Contreras says. Gardner notes that people who should generally not use BFR include (but are not limited to) those with current or past blood clots, a diagnosis of a blood clotting disorder, bleeding disorders (including thrombophilia), and infections within the involved limb, as well as women who are pregnant.
The Bottom Line: Should You Try Blood Flow Restriction Training?
In the hands of an experienced practitioner, BFR training can be a useful tool to support musculoskeletal rehabilitation for injury recovery — and to support strength and muscular conditioning training for athletes and some patients with chronic conditions. “Any athlete could potentially benefit from blood flow restriction training,” says Gardner. “Almost all Olympic athletes include strength training in their preparation, and thus there is a way in which blood flow restriction could be incorporated.” She does note that if it BFR is used, it should be part of a multimodal approach, including other forms of exercise, resistance training, and aerobic training. And in order to be safe, as well as reap maximum benefit, it is important that the evolving practice guidelines for blood flow restriction be followed under the guidance of a skilled physical therapist or physician. If you want to try BFR, Aueron suggests consulting with your physician and a physical therapist who has formal training in BFR who could help you decide whether BFR may be a safe and effective therapy to add to your athletic or rehabilitation program. RELATED: Dry Scooping: Why Health Experts Warn Against Trying the Viral TikTok Trend
