BFR Training
Blood flow restriction can deliver impressive results for strength, size and muscle recovery
When something sounds too good to be true, it usually is. Cut-price car? Call the mechanic. Weight-loss tea? Try running instead. A quick route to strength, size and improved recovery? Well, hear us out.
Blood ow restriction training (you might also see it called ‘occlusion training’ or ‘hypoxic training’) isn’t a di cult term to unpack – but the physiological processes involved take a fair amount of explaining.
Put simply, BFR (the acronym used from here on out) involves restricting the ow of blood out of the working muscle. at’s achieved by applying a pressure wrap around the top of the working limb(s): the armpit-ends of your arms for biceps and triceps, and the groin-end of your quads for leg work. anks to a process called arterial ow, blood is able to enter the muscle, despite the pressure being applied, but once it’s in there the blood nds its veiny exit routes partially blocked, and only a small amount can take its leave. As a result, the muscle swells and an almighty muscle pump is delivered.
Now, this is where things get technical, so to help us get our heads around things we spoke to Dr Warren Bradley, founder of Hytro, the company making activewear with integrated BFR straps – so the bene ts of this protocol can be achieved anywhere.
“e process by which the body repairs damaged muscles and stimulates growth in muscle is called ‘muscle protein synthesis’ (MPS),” says Dr Bradley, “and the extent of growth is heavily dependent on the body’s ability to stimulate MPS. BFR causes muscle swelling, through pooling of blood in the muscle as the muscle exercises, and tissues quickly become deprived of oxygen, creating a condition called ‘hypoxia’. at results in increased metabolic stress
and a signi cant increase in the production of hormones responsible for muscle growth, which collectively increase MPS. “On top of that, the low-oxygen environment causes accelerated ATP breakdown (ATP being the energy-giving molecule), which rapidly fatigues slow-twitch muscle bres. at causes the body to recruit fast-twitch muscle bres (strength bres) to help perform the exercise, training all bres concurrently.” at’s very good news, Dr Bradley continues, because it creates a state of enhanced muscle growth without the need for lifting heavy loads – in fact, very light weights (as little as 20 per cent of your one-rep max) are all that’s needed. e problem, until now, has been the application. Typically, BFR has been the reserve of elite athletes, because the cu s used are cumbersome and, crucially, need to be applied to exactly the right position.
WORD OF WARNING
Which leads us onto a much-needed disclaimer: do not attempt to create your own blood ow restriction device at home. Hytro’s BFR garments have undergone rigorous testing to ensure the straps are in precisely the right position – try doing it yourself and you risk causing serious muscular or, worse, vascular damage. It’s also vitally important that you don’t do too much, too soon.
“You wouldn’t go and run a marathon with no training – you would build up the miles gradually,” says Dr Bradley. “It’s such a powerful hypertrophic
stimulus and such a lot of pressure on the muscle that you can equate it to going to the gym for the
rst time in a year and smashing a load of heavy squats – you’re going to be sore. Even if you’re an elitestandard athlete, because this is something new for the muscle that it’s never experienced, it’s as if you’ve never been to the gym.”
A word, also, on blood clots: the main thing people might be worried about with BFR. Firstly, if you are t and healthy with no history of blood clots, the research says this style of training poses no more risks than regular resistance exercise.
However, if you have an existing blood clot, or there’s a family history of them occurring, it’s probably best to steer clear – or at the very least consult a healthcare professional rst. at’s because the ow of blood once the straps are removed can cause existing clots to shift around the body – potentially to vital organs – which, needless to say, is incredibly dangerous.
Dr Bradley, though, points out that Hytro conducted a safety study with Queen Mary’s University London and Pure Sports Medicine, “and that proved that our garments are safe and e ective, with no adverse e ects.”
FIND THE FLOW
We’ve touched on the ‘pooling’ stage of BFR – when the muscle lls with blood – but it’s when the straps are removed that most of the magic happens. Because while the blood and the associated musclebuilding hormones pool in one place when the pressure is being applied, once the straps are o it oods back through the body – with force. And that creates bene ts far beyond the working muscle.
“It’s called the systemic e ect,” explains Dr Bradley, “and basically what that means is once you’ve built up the muscle-building hormones in the restricted limb, when you remove the strap the heart is going to pump those hormones around the body. So even if you did a leg session yesterday and you’ve got some muscle tears you need to regenerate – with protein and rest – a BFR session is going to improve recovery because those hormones are going to end up in your legs to boost the repair process.”
at’s what makes BFR such an e ective recovery protocol – and why sports teams have long been using it to help their athletes bounce back quicker from injury. Because not only does the post-strap blood ow send hormones to previously worked muscles, it also drags waste materials out of your joints. “at’s called reperfusion,” explains Dr Bradley. “If there are any micro-traumas (cartilage chips and so on) the blood removes that in ammation and the body can excrete it very quickly.” Normally, after a workout, game of football, or other high-exertion sport, it takes the body a couple of days to truly recover, because the process of removing those waste products – with the regular ow of blood – is much slower. “What BFR does,” adds Dr Bradley, “is remove them immediately at source. at’s why it is so impressive at improving recovery.” Josh Charnley, tryscoring sensation for rugby league out t Warrington Wolves, bene tted directly from Hytro’s BFR straps during an injury spell on the sidelines last year.
“I WAS ONLY LIFTING 7.5KG TO 10KG, REPPING OUT FOR A MINUTE AT A TIME. IT WAS HORRIBLE! BUT I HALVED MY RECOVERY”
“I dislocated my shoulder on the second last game of the season,” he says. “I couldn’t really lift any weights, so I went to see a surgeon and he said I needed an operation. I had the op, and within four or ve days I went back into training and was introduced to Hytro BFR. “I was told it would be bene cial for me, because I couldn’t lift heavy weights but I was going to be able to keep my strength and size up. I started that from week on of rehab and used it for every upper body and recovery session. Within just four weeks, I was back to normal strength. “I was only lifting 7.5kg to 10kg, repping out for a minute at a time. It was horrible! But it de nitely bene tted me. I halved my recovery, because I was given 14 weeks and I was back playing in seven.” ere’s another way of looking at this, too. “You can actually train a non-occluded muscle and it will get worked beyond that of normal training,” Dr Bradley adds. “What I mean by that is, say you’re on a bench press and you occlude the arms – using a typical protocol of 20-30 per cent one-rep max (1RM), so very light weight, for around 30 reps, followed by three working sets of 15 reps – the triceps fatigue rapidly because of the occlusive stimulus, so the pectoral muscles end up taking a bit more of the load than they normally would. at increases muscle bre activation and therefore forces the body to perform like an advanced lifter – even if you’re a novice.”
PUTTING IT INTO PRACTICE
‘Light weight’ is the key phrase here. No matter how seasoned a lifter you are, a 6kg pair of dumbbells are soon going to feel four or ve times that weight. More important, though, is the fact that BFR is best suited to high reps, low rest, because the aim is to get as much blood into the working muscle as possible. “All you need to do is one or two exercises at the end of your workouts using BFR,” says Dr Bradley, “so you nish your regular session, then strap the BFR top or shorts into 70 per cent tightness and pick one or two exercises. “Let’s say you’ve done an upper-body workout. You could pick bicep curls and skullcrushers, and choose a very light weight for 30 repetitions. ose reps are simply to get blood into the arm and get it stuck there, so return ow is heavily impeded. After that, take 30 seconds rest and go again for 15 reps. While the rst set would have felt easy, the next sets will not, because the muscles are tired and full of blood. at means you’re essentially training in a state of fatigue, which would normally take 30 or 40 minutes to get to with a regular session. Aim for three sets of 15 reps after the initial set – though you might well nd you can’t complete the reps, because even light weight is going to feel very hard to move.
“Once you’ve done that, your muscle will be maximally recruited and you don’t need to do anything else. Take the strap o for two minutes to let the blood
ow back, then move on to the next exercise.”
One of the main advantages of BFR is that it doesn’t cause central nervous system (CNS) fatigue. When you lift heavy weights, you put your CNS under a lot of pressure, but lighter BFR loads avoid that.
Don’t think it’s just for your arms or quads, either. ough the straps will be located at the top of either your biceps or thighs, the blood is going to ow to whatever muscle you’re working. So if you do opt for a Hytro garment, you can target any upper-body muscle with the BFR top, and any lower-body muscle with the BFR shorts.
ADDED BENEFIT
“Normally you would tag a BFR workout onto the end of a regular workout, because it augments the results from your training,” says Dr Bradley. “When you do a weights session you get your muscle-building hormones to a certain level; by adding BFR you are signi cantly enhancing those levels.”
at point is key: BFR doesn’t replace your regular training, it enhances it. If you’re ring on all cylinders, strapping in at the end of your workouts takes nisher exercises to another level: bene tting not only the muscles in question, but even the just-worked areas you trained yesterday or the day before.
On the other hand, if like Charnley you’re working below full capacity, blood
ow restriction provides your muscles with enough stimulus, with light weight, to maintain strength and size – while kickstarting your body’s recovery processes – until you’re back to your very best.
It’s no shortcut or quick- x, but it can be an incredibly powerful tool in your workout armoury.