Blood-flow restriction: Why men are tying up their arms at the gym to build muscle

It allows you to lift lighter weights but get greater results

You can use straps or ties (Instagram/schaferfitnessministry)

There are no shortcuts to getting fit - it takes hard work, dedication and, usually, a fair few visits to the gym.

But that doesn’t mean people aren’t always looking for ways to maximise their workouts and speed up their progress.

And one way they’re doing that is by tying up their arms. Yes, really.

You may have seen men - for it is mostly men - doing so in the gym, whether with bands or straps. “Why are these men tying up their biceps?” you wonder to yourself.

Well it turns out there's real science behind it.

The technique is called blood-flow restriction and it’s supposed to help you build muscle, improve endurance and recover from injury.

Surprisingly, it also works while lifting rather light weights, or even none at all.

Blood-flow restriction training was invented by a man called Yoshiaki Sato in Japan, where it’s known as KAATSU.

Now in his 60s, Sato first realised the potential of KAATSU when he was 25 - after breaking his ankle in a skiing injury that should’ve taken him six months to recover from, Sato used blood-flow restriction to be back to full health in just six weeks.

Often when people break a leg, it ends up far skinnier than the other one after the cast comes off, but blood-flow restriction training reportedly prevents this: “There’s some evidence that applying blood flow restriction in the absence of exercise may be useful for helping to maintain muscle size and strength,” Jeremy P. Loenneke, a professor of health and exercise science at the University of Mississippi, told Tonic.

Health experts are excited about the technique’s potential in this vein, but it’s also popular amongst athletes, bodybuilders and those who want to work on their guns.

Here’s how it works:

You tightly wrap up your upper arm, restricting blood-flow from the biceps. You then do bicep curls at a much lower weight than you would usually.

“The trapping of the blood is going to trap lactic acid,” says Zachary Long, director of physical therapy at Carolina Sports Clinic. “As you’re exercising, you’re building up more and more lactic acid… the growth hormone release that occurs in response [to that] is actually higher than what we see with heavy resistance training.”

Whilst the prospect of lifting light weights and building muscles at a quicker rate might sound appealing, those who use the technique says it hurts. A lot.

“It should feel like the largest muscle burn you've ever had,” says Long.

Personal trainer Harry Smith believes the typical training method of straight sets and reps, progressively increasing the load over time will lead to better longer term progress, but that there are benefits to blood-flow restriction training: “It’s very useful for training around an injury that doesn’t allow for heavier loads to be used,” he explained to The Independent.

“Blood-flow restriction training forces you to use much lighter loads than you usually would as the restricted venous return traps blood in the muscle, limiting its range of motion to an extent and causes a huge build-up of metabolites and lactic acid.

“This ‘pumps’ up the muscle, really stretching it, this sensation is incredibly painful and may stimulate muscular hypertrophy because of this swelling effect.”

He believes those who aren’t injured would be best placed to stick to traditional training, but if you’re injured and can’t do that, blood-flow restriction can be a good option.

You need to make sure you’re doing it properly though - if your muscles go numb or feel tingly, you’ve tied your strap too tightly.

And it could pose risks for some people, so experts warn against doing blood flow restriction training if you have high blood pressure, varicose veins or deep-vein thrombosis, for example.

You shouldn’t wrap the straps or ties anywhere other than the tops of the arms or legs either.

But with many people waxing lyrical about the benefits of blood flow restriction - for both fitness and recovering from injury - you may start seeing more and more women and men tying up their arms at the gym soon.

If you want to give blood-flow restriction a try, be sure to ask a fitness professional to show you how to do it safely.