Blood flow restriction (BFR) training is an interesting “new” practice in fitness and rehabilitation. (I say “new”, but it has actually been around for decades—first introduced in Japan by Dr. Yoshiaki Sato in the ‘70s as what he called “Kaatsu” [a Japanese term meaning “added pressure”].) I have known of it for a while, but dismissed it a bodybuilding technique that favored sarcoplasmic hypertrophy (increased muscle volume) and had little benefit for strength and performance. Recently, however, I was caused to explore BFR after my 16-year-old was a passenger in a car that was broadsided by a pickup truck. All things considered, his injuries were minor, but they were enough to put a damper on his training goals for his next wrestling season. I have been blessed to have a role in the education of a number of physical therapists and athletic trainers. I reached out to some and the overwhelming response was “BFR.” So, I dove into the literature. I ordered a set of cuffs, and I got certified. Moreover, I starting trying it for myself.
BFR training is, in a nutshell, performing common exercises at a much-reduced load which removes the stress on the joints, ligaments, tendons, etc. from high-intensity resistance exercise. It is commonly understood that one must lift weights in excess of 70% of the one-repetition maximum (1-RM). With BFR, these loads are reduced to 20-40% 1-RM (or less—some research has indicated that passive BFR [restricted blood flow with no exercise] can help minimize atrophy from injury or immobilization). A standard protocol for BFR training is four sets for 30+15+15+15. Blood flow is occluded (“restricted” is a better term) at a percentage of arterial occlusion pressure (AOP) using bands or inflatable cuffs. Common limb occlusion pressures (LOP) are 50% of AOP for the upper extremity and 80% AOP for the lower extremity.
While an increasing number of bodybuilders are using BFR, and an increasing number of physical therapists ar seeing its benefits in post-injury rehabilitation, there may be a place for it in the programming of exercise for the aging exerciser. Why? BFR can stimulate muscle hypertrophy and some strength increases while minimizing excessive stress on the spine and joints. One may get the benefits of heavy resistance training without the heavy weights. (Consider it if you have had to give up squatting because of back issues, for example.) Even the serious powerlifter can benefit from decreasing the load stress while maximizing the metabolic stress to the muscle.
While the proposed mechanisms of BFR are beyond the scope of this writing, it can be stated simply that BFR simulated high-intensity resistance exercise without the heavy loads. Partial occlusion of blood flow to the limb decreases arterial blood flow (the muscle still gets some oxygenated blood) while trapping venous blood in the muscle. This results in an increase in metabolites, cellular swelling (“pump”), and increases the recruitment of fast-twitch muscle fibers (the reduced oxygen in the muscle and buildup of metabolites fatigues the slow-twitch fibers and tricks the muscle into using fast-twitch fibers at a much lower intensity). This triggers the many mechanisms for muscle hypertrophy. I would add, however, that heavy-load training is still necessary to increase strength and performance. Thus, for the athlete, BFR should be considered a supplement to regular training.
There are contraindications to BFR training. These include1:
- Venous thromboembolism
- Impaired circulation or peripheral vascular compromise
- Previous revascularization of the extremity
- Extremities with dialysis access
- Acidosis
- Extremity infection
- Tumor distal to the tourniquet
- Medications and supplements known to increase clotting risk
- Open fracture
- Increased intracranial pressure
- Open soft tissue injuries
- Post-traumatic lengthy hand reconstructions
- Severe crushing injuries
- Severe hypertension
- Elbow surgery (where there is concomitant excess swelling)
- Skin grafts in which all bleeding points must be readily distinguished
- Secondary or delayed procedures after immobilization
- Vascular grafting
- Lymphectomies
- Cancer
The equipment required can vary from elastic tourniquets to inflatable cuff (similar to blood pressure cuffs) that can be manually or automatically inflated to the desired LOP. These can range from $30-40 to hundreds of dollars to thousands of dollars. In general, the tourniquets can be effective, but these may lack the precision of cuff pressure. (In general, the recommended tourniquet pressure is adjusted to a rating of 7/10 [10 being full occlusion].) Cuff AOP can be determined using Doppler, pulse oximeters, and palpation of the pulse (e.g., radial pulse for the upper extremity and dorsalis pedis pulse in the lower extremity). The latter takes some skill and practice; the former require some additional expense (note that is a pulse oximeter is used one the records continuously is needed). The choice of equipment is individualized and depends largely on budget and the level of precision desired. I opted for a moderately priced inflatable cuff from The Edge Mobility Systems2. There are more expensive systems (B Strong3 [pictured above] is a nice system, as well, for a couple hundred dollars more; and there are much more expensive systems), but this one has suited my needs this far.
So, what’s it like? Honestly, I have never experienced quite the same pump. Leg day is more fatiguing than any 10×10 squat workout I have ever done. Squatting at 20% of my 1-RM feels pretty darn effective. I just started a three-week program, so time will tell. I am confident I will see positive results (as a hard gainer when it comes to legs). I am also looking forward to using BFR to help my son get back up to his wrestling weight and beyond.
Be your best today; be better tomorrow.
Carpe momento!
1https://www.gallowaytherapy.com/bfr-contraindications/
2https://edgemobilitysystem.com/collections/the-fitness-collection/products/edge-restriction-system-bfr-cuffs
3https://bstrong.training/pages/product-2