I’m excited to be trialling and learning about the latest in consumer fitness tech, Blood Flow Restriction (BFR). It’s not a new technology, as elite athletes and professional sports teams have been using BFR training for several years (and bodybuilders might have used a general strap) but it’s now emerging into the mainstream through consumer-friendly products. One of these is Hytro Performance Tech-Wear, which was kindly sent to me to try.
I was eager to understand more about the technology behind Hytro’s BFR clothing so I spoke to one of the three co-founders, Dr. Warren Bradley for a deeper dive into how BFR training works and why Hytro is different.
During his PhD in human physiology and nutrition, Warren saw sports clubs and athletes using BFR for rehabilitation and was intrigued at how rapidly muscles recovered and grew. He went on to study the ‘solid science and research’ and co-developed ‘the world’s first patented blood flow restriction tech-wear for rapidly enhancing muscle and accelerating recovery’.
Instead of pneumatic cuffs or bulky pressure gauge equipment, manual straps are integrated into Hytro garments so that athletes could access BFR technology more easily, for increased performance and physiological adaptations.
Could this be the future of fitness-tech?
Let’s start with the basics, what is blood flow restriction (BFR) technology?
Warren: BFR involves applying a strap or cuff to the arms or legs, allowing oxygenated blood to flow into the limbs while restricting the return flow; also known as occlusion (closing of the blood vessel). Through metabolic stress (the same as you’d get with strength training and exercise) this increases muscles fibre activation and causes the muscle to swell with an up-regulation of muscle-building hormones. This leads to a rapid increase in muscle strength and size.
What are the benefits of BFR for fitness?
Warren: With BFR you don’t need to use heavy weights to get the same effects. Improvements in muscles size, strength and power can be achieved when working at just 30% of your one rep max or even bodyweight. Studies have found just two weeks of BFR training is enough to significantly increase muscle size, strength and power, through an increase in muscle protein synthesis.
How does BFR work for hypertrophy?
The strap basically tricks the body into up-regulating muscle building hormones – a bio-hack essentially as we’re tricking the body into adapting to exercise. But the fantastic thing is with blood flow restriction is because you can get adaptation results through low load and weights, it’s really good for rehabilitation. If you’ve just come back from a knee injury and just returning to training, you may not be able to squat heavy. So instead of your old 100kg one rep max (1RM) you can now squat with 20 or 30kg with BFR and while there’s barely any loading on the joints (compared to your 100kg squat), you’re still getting a really intense workout and the muscles are still going to hypertrophy without having to lift heavy.
How do I train with BFR occlusion strap?
The traditional way of using BFR is to work one muscle with one exercise so that you maximally stimulate that muscle. So say you want to work on your biceps; you would pick an exercise, let’s say a dumbbell curl and you’d pick a weight that’s around 30% of your 1RM. So you do four sets with the straps on tight (50-80% occlusion); the first set at 30 reps, rest 30 seconds and repeat the second, third and fourth sets at 15 reps. The first set is to get the muscle contracting and blood pumping to it to prime it.
How do the occlusion straps work within the apparel?
Warren: One of the safety parameters for BFR is the specific location of the cuff. Hytro garments have the strap in the exact precise location on the arm or the leg, meaning it’s safe and effective for use every single time. This is important because when you’re applying the blood flow restriction, you shouldn’t be over the meat of the muscle as that can cause sciatic or nerve damage. Alongside the location of the strap, the width is also important. Based on research, a larger cuff becomes difficult to apply the occlusion needed and a smaller strap would feel uncomfortable.
How tight should the straps be pulled?
Warren: You need to be including anywhere between 50% to 80% of pressure around the limb – that’s based on a scale of 100% occlusive pressure, where 100% is completely stopping the blood flow and 0% is no occlusion at all. The research has shown is that practical BFR, ie without pneumatic cuffs and pressure gauges, a seven out of 10 subjective measure is going to be sufficient and effective. We have a numbering system on the garment strap so there’s a visual reference too. It’s a subjective measure so you just pull the straps to what feels like a seven out of 10 for you on that day.
What if I want to train my shoulders but the straps occlude around the biceps?
Warren: Because the occluded muscles (those below the occlusive strap) fatigue rapidly, it forces the deltoids and shoulder muscles to recruit more fibres for contraction to take the extra load that the occluded muscles cannot manage. One particular study showed a 16% increase in chest muscles activation when using BFR on the upper arms.
What other benefits of BFR are there?
Warren: It’s great if you’re training at home without heavy weights, which is an interesting one for our recent and current lockdown situations as people try to figure out how to keep the stimulus going with lower weights. As a scientist, I put my I’ll put my heart on the ground and say this is the best type of training you can possibly do at home right now, because it’s the only one that can stimulate muscles to the maximum capacity without the load.
The elderly is another demographic BFR can help as it can regenerate muscle, regenerate bone density, reverse sarcopenia and reverse osteopenia. Something as simple as wearing a strap and going for a walk (even with a zimmer frame) the blood flow restriction will help to regenerate muscle tissue and give them some strength back.
Where do I get more info on BFR and the benefits for fitness, sports performance and rehabilitation?
Warren: We’ve spent a lot of time, money and investment developing the Hytro products on the back of published scientific research papers. A few of these include:
Blood flow restricted exercise for athletes: A review of available evidence
Blood Flow Restriction Exercise: Considerations of Methodology, Application, and Safety
Improving strength and power in trained athletes with 3 weeks of occlusion training
My verdict on the Hytro top
For the last few weeks I’ve been wearing the Hytro long sleeved female performance top (£129, gifted) for my home-training. The product arrived in a beautifully presented branded drawer-box and tissue paper wrapped. The instructions are found through a QR code to minimise on packaging and paper.
The first thing that stood out was how soft and comfortable the fabric was, so I found myself happy to wear the top for its style and comfort alone – always a good thing. I wore it with a light sports bra underneath as the top didn’t have any double lining or padding around the chest. I liked the added touch of the thumb holes though, and the fit was very flattering.
The arms were initially a bit tight to get on (Hytro is developing garments for different arm sizes) but once in place the straps were sitting comfortably at the top of the bicep muscle without any discomfort. It was then super easy to pull the straps as tight or as relaxed as you like and fix them down with the velcro ends. The Roman numbers around that strap are not that obvious but it almost doesn’t matter as the instruction is to pull the straps to your individual 7/10 tightness.
Training in the top is super super comfortable and I’ve worn it for several arm and shoulder workouts now. I’m excited to see how BFR training is adopted by the mainstream and how Hytro evolves with this.
If you’re interested in finding out more about BFR technology and BFR training visit Hytro.com
READER OFFER: If BFR training is for you then Hytro is offering my readers a fantastic 20% off Hytro performance tech-wear with the code: YANAR20. Simply apply code at checkout. hytro.com
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