Blood Flow Restriction (BFR) Training
BFR has been used in bodybuilding circles for many years for muscle hypertrophy, however, recently we’ve seen it makes its way into the rehab & general strength & conditioning arena.
It involves the use of an inflatable tourniquet, such as an elastic band or cuff, around the top of the arm and/or leg to restrict blood flow during exercise.
The goal of BFR training is to increase strength gains while lifting lighter loads which reduces the overall stress on the limb and avoids muscle breakdown.
While it many applications for healthy sporting populations, in the rehab space, BFR can be very helpful for individuals who cannot, for a range of reasons, perform maximal loading through a limb or body area, or perform training at high loads.
Reasons for this may be:
• Post surgery (such as ACL reconstruction)
• Injury & reduced weight bearing ability
• Inability to increase intraocular pressure due to eye injury
• During relative rest periods to deload joints & tendons
While it should not always replace traditional strength training, BFR can be use as an effective supplement for short periods or as a part of a balance training program.
How does it work?
“Under normal conditions, the metabolites produced in your muscles during hard exercise serve as cellular signals that trigger adaptations in your body – bigger muscles after resistance training, for example. With blood flow restriction, your muscles are forced to stew for longer in these metabolites, triggering bigger adaptations.” – Dr Ed Le Cara
Blood flow restriction training works by:
• Blocking venous return without blocking arterial flow
• Facilitating growth hormone production
• Creating cellular swelling
• Fatigue recruiting more Type 2 fibers
• Metabolites, especially Lactate, accumulating and stimulating muscle growth
Basically, the loads required for muscle hypertrophy when undergoing BFR training are far lower than what’s needed in traditional exercise to stimulate muscle growth and hypertrophy.
To cause muscle growth in traditional exercise, we generally need to be lifting at loads greater than 65% of our 1 rep max. with BFR, we can use loads at about 20-30% of the 1 rep max and still see considerable improvements in muscle size and strength.
The basic science behind BFR training (if you’re interested):
To put it basically, in traditional resistance training and exercise, when we load muscles at a high load or intensity, it causes an inflammatory reaction (which is normal), which then helps to grow the muscles. This is often the cause of delayed onset muscle soreness (DOMS) occurring after working out and can reduce the ability to back up multiple high load workouts or competitions.
By restricting the blood flow around a muscle, it reduces the oxygen delivery to the area. Oxygen is required for development of type 1 (slow twitch) fibres, but not so much for the bigger type 2 (fast twitch) fibres. To recruit these type 2 fibres during traditional exercise, we normally need to exercise at a high intensity, however reducing the oxygen available flips this around and allows us to recruit and build these fibres without
Studies have shown that BFR training creates a large increase in muscle protein synthesis, but without the inflammatory effects of high load training. During BFR, growth hormone secretion can be up to 170% higher than with traditional exercise. This has a protective effect on tendons and muscle collagen fibres, which can also serve us well in helping to prevent injury and improve recovery.
Contraindications
As with any type of training, there are certain individuals who should not participate, or should be closely monitored when doing this type of training.
These include:
• Circulatory issues or clot risk (DVT)
• Heart disease/insufficiency
• Severe, uncontrolled hypertension
• Diabetes
• Sick Cell Anaemia
• Varicose Veins
• Pregnancy
• Less than 12 years of age
• Open would or incision
• Infection
• Cancer
• Lymphoedema
When starting BFR training, it’s important to make sure that the level of occlusion/restriction is right for you, and then you’re doing the correct number of repetitions and sets at the right level of intensity, so professional guidance in getting started with this type of training is highly recommended!
For more information, or to find out if and how BFR training could be useful for you, please feel free to get in touch with us and we can chat further!