February 27, 2020 at 12:00PM by CWC
Blood flow restriction training may sound like some kind of kinky bedroom activity. (Hey, I’m a fitness and sex writer. My mind goes there.) But this on-the-rise lifting technique, sometimes called occlusion training or abbreviated as BFR, is actually a G-rated method that athletes use to get stronger muscles, faster—without using ultra-heavy weights.
To understand BFR, you need to know a bit about about the circulatory system. Ready? Your arteries carry oxygenated blood away from your heart to the rest of your bod, while your veins carry deoxygenated blood from your bod back to your heart. During blood flow restriction training, a specialized cuff—one that looks like a doctor’s blood-pressure cuff—is wrapped around one’s arm or leg near the shoulder or hip. This cuts off venous flow from the limb while still permitting some arterial flow, ultimately reducing the amount of oxygen available to the muscles.
At first blush, depriving your muscles of oxygen sounds like it can, in no way, be a good thing. But it can actually help to build muscle mass. Here’s why: Whenever you lift heavy weights, your muscle fibers work so hard that they quickly become depleted of oxygen. This metabolic stress is one reason why lifting weights makes muscles grow. By cuffing up, you mimic that limited-oxygen environment. “It actually tricks your brain into believing it is using heavier weights than it’s using,” says Nicholas Rolnick, DPT, MS. The result? More muscle growth with less weight-induced stress on the limb.
“Originally, this was done in operating rooms with medical grade tourniquets to help preserve the muscle-mass in amputees,” says Rolnick. But then professional sports teams started using it as a training strategy, and now experts are billing it as The Next Big Fitness Trend.
“BFR training is a good way to give your joints a break from the stress of heavier lifting.”—Nicholas Rolnick, DPT, MS
Research backs up the potential perks of BFR training. One 2017 study published in the International Journal of Exercise Science, for instance, found that during BFR, lifting just 20 percent of your one-rep max can result in “significant improvements in muscular strength.” This is W-I-L-D, if you think about it. Let’s say your one-rep max for an overhead press is 100 pounds. (You go!) With the BFR cuff on, however, pressing 20 pounds for a ton of reps—75 reps over four or five sets, to be exact—can produce the same amount of muscle growth as lifting heavier.
Who can benefit from blood flow restriction training?
Because BFR gives you #gainz with relatively light weights, Rolnick says BFR training can be an amazing tool for those who are unable to lift heavier weights due to injury, recent surgery, or osteoporosis.
John Gallucci, Jr., DPT and CEO of JAG-ONE Physical Therapy, agrees that those coming back from injury may strongly benefit from BFR. “Following an injury, athletes are usually unable to lift loads at the level required to maintain strength or promote new muscle mass,” he says. “BFR allows the physical therapist to begin the strength and hypertrophy phases of rehabilitation much earlier.”
Healthy people, too, can reap the BFR rewards—especially those who are trying to put on muscle mass without wearing out their knees and elbows. “BFR training is a good way to give your joints a break from the stress of heavier lifting,” Rolnick says. That’s why it’s especially popular among bodybuilders.
Still, BFR is not appropriate for everyone. Because the technique reduces blood flow, Rolnick says it’s not safe for those who have a prior history of a blood clot, clotting disorders, cardiovascular disease, or circulatory issues.
How to start BFR training
Like tattoos and vitamin IVs, blood flow restriction training is not something you should attempt to DIY—at least, not at first. Dr. Gallucci says it’s only safe to learn under the supervision of a physical therapist or other certified expert, who can help you determine if BFR is a good strategy for you in the first place.
If it is, they’ll likely use a special tourniquet system with a blood-pressure reader attached. “Having the monitor reduces the chances that you’ll completely cut off blood flow or cause any nerve or muscle damage,” Rolnick says. While bodybuilders on Instagram sometimes use muscle floss or elastic bands for BFR, Rolnick says this is not the safest way to go about it. “The issue isn’t that it doesn’t work—the floss will restrict the blood. The problem is that you can’t reliably assess how much pressure you’re putting on the limb.” And if you completely cut off blood flow, you risk creating a blood clot. Yikes.
Once you’re cuffed in, Rolnick says you’ll typically choose weights sized anywhere from 20-40 percent of your one-rep max. Then, you’ll perform 75 reps of an exercise in a 30-15-15-15 manner: 30 repetitions on the first set, followed by three sets of 15 with 30 seconds of rest between sets. The whole shebang usually takes under 10 minutes, but Rolnick warns that it’s uncomfortable. (Think of the aching sensation you get during a blood-pressure reading, then add weights.)
Rolnick recommends doing five supervised BFR sessions over two to three weeks to acclimate to the unique stress (and sensation) of the technique. Once you know what you’re doing, your provider may give you the the green light to purchase an at-home BFR machine and use the cuff independently. Looks like every season may soon be cuffing season—at the gym, that is.