Learn how blood flow restriction training could help you improve your fitness and bounce back after an injury.
It’s common for experienced exercisers to utilize novel — and, to outsiders, strange-looking — tools to increase the challenge and get more value out of their typical workouts. Endurance athletes, for instance, may use altitude masks to limit airflow and potentially improve performance variables such as VO2 max and power output. And recently, blood flow restriction devices have increased in popularity.
Also known as occlusion training or BFR training, blood flow restriction training involves exercising with a tourniquet (commonly used in research settings) or an elastic band (often used in commercial settings) wrapped around your arm or leg to reduce blood flow in and out of the area, says Matt Delany, the Director of Programming and Innovation at Equinox.
In reducing circulation, blood flow restriction training is meant to drive a build-up of metabolites (such as lactate and diprotonated phosphate) and reduce oxygen supply to the working muscle, leading to muscular fatigue and increased motor unit recruitment, explains Delany. “All of this allows an individual to work at a lower load and intensity while still achieving similar benefits [as high-intensity training],” he notes.
But is blood flow restriction actually a worthwhile fitness tactic? Here’s what science says.
The Benefits of Blood Flow Restriction Training
Restricting blood flow during resistance exercises can be advantageous. Research shows that long-term BFR training increases muscle size and strength, improves physical function and endurance, and enhances muscular power, according to a 2021 review published in Frontiers in Physiology. For example, a small 2020 study found that blood flow restriction training at low intensities improved strength and endurance just as well as high-load resistance training.
Often, the loads used during blood flow restriction training are just 20 to 50 percent of a person’s one-rep max, according to the Frontiers review. That’s why the training tool can be valuable for people who aren’t able to safely use higher loads, such as elderly individuals, recovering athletes, and patients with high-risk medical conditions, per a 2021 review published in the International Journal of Sports Physical Therapy. BFR training is also commonly used in rehabilitation settings, says Delany; folks recovering from injuries can gain the strength and size associated with heavy resistance training while working at lower intensities that are more appropriate for their physical capabilities, he explains.
That said, you may want to take these findings with a grain of salt. Many of the blood flow restriction studies published thus far largely included college-aged men, and few have focused on female participants. Plus, if you’re using an elastic band or a similar gadget, you may have trouble creating the same level of restriction day after day, which could impact your results, according to the Frontiers review.
The Risks of Blood Flow Restriction Training
As with many fitness modalities, blood flow restriction training does come with potential risks. In the short term, you may experience numbness, bruising, skin abrasions, delayed-onset muscle soreness, and general discomfort, says Delany.
“More serious complications are generally cardiovascular-related and can range from increased hypertension and stroke to blood clots and other cardiac events,” he adds. “Because occluding blood flow will increase blood pressure, it is important to monitor it as you are performing your exercises.” Many high-tech BFR devices are equipped with built-in monitors, but blood pressure is more difficult to track if you’re using an elastic band, he notes.
Because of those risks, you should always consult your healthcare provider before trying blood flow restriction training, says Delany. This green light is particularly important for folks with hypertension, diabetes, cardiac disease, clotting disorders, active infections, vascular issues, a history of stroke or deep vein thrombosis, or who are pregnant, he adds.
The Bottom Line
Blood flow restriction training can be beneficial in the appropriate circumstances and at the proper dose, says Delany. If you get clearance from your healthcare provider, it’s generally recommended to perform BFR training two to three times per week for just 10 to 20 minutes per session (equating to about two to four exercises), he says. Remember to take the time to re-establish normal blood flow between movements, he suggests.
Still, most exercisers shouldn’t throw their traditional training program out the window. “For general lifters, [blood flow restriction training] is not some kind of magic modality that will unlock some kind of secret strength and performance gains,” says Delany. “Those who can train compound patterns at normal loads and intensities should continue to do so while considering if and where this could fit into their program.”