What is Blood Flow Restriction Training (BFRT)?
Blood flow restriction, also known as occlusion training, is a method of partially reducing venous blood outflow from muscles in the limbs by applying a cuff (tourniquet) close to the area being trained. This allows for more blood to pool in the muscles, resulting in a stronger growth stimulus, with trainees having to use much lighter weights (as light as 20% of 1RM).
What is the Idea Behind Blood Flow Restriction Training?
The idea behind blood flow restriction training is to mimic an environment of high-intensity training that results in superior muscle and strength gain without having to use as much weight or train for as long.
This reduces strain on the joints and connective tissues and allows trainees to train effectively with far lighter loads. It works particularly well for home training (if the lifter doesn’t have heavy weights) and can be useful when dealing with an injury and trying to keep as much muscle as possible.
Thanks to a couple of mechanisms, trainees can achieve more growth with less weight by limiting the venous return of blood from the muscles.
First, forcing more blood to pool in the muscles increases metabolic by-products, such as lactic acid and hydrogen ions. These play a crucial role in hypertrophy signaling.
Second, by accumulating more metabolic waste, trainees can exhaust their muscles with far less weight and achieve greater motor unit recruitment. This means slow-twitch muscle fibers get worked, but fast-twitch fibers (which are typically reserved for quick and intense activities) also must engage.
Examples of Blood Flow Restriction Training
Example 1: Legs
Step 1: Place the cuff at the top of the thigh, just below the glute.
Step 2: Perform a movement that targets the quadriceps, adductors, hamstrings, or calves. Examples include leg extensions, leg curls, and calf raises
Example 2: Arms
Step 1: Place the cuff at the top of the arm, around the bottom of the shoulder.
Step 2: Perform a movement that targets the biceps, triceps, or forearms—for example, bicep curls, tricep extensions, or wrist curls.
Placing a cuff at the top of the arm can also have a positive impact on shoulder training.
5 Tips for Effective and Safe Blood Flow Restriction Training
1. Cuff the Right Spot
It’s generally best to position the cuff at the top of the limb, close to the hip or shoulder joint.
When applying a cuff to the thigh, position it just below the buttock so it doesn’t obstruct movement. For the upper arm, place it just below the shoulder, ensuring it doesn’t limit the range of motion.
2. Tighten it Correctly
This is somewhat subjective and will take some experimentation. It’s generally recommended to aim for a tightness level of 4 to 7 out of 10, where 10 is as tight as possible. A middle area between no tight at all and so tight that my limb is starting to go numb is ideal.
Experiment with yourself first to see how BFR feels like before coaching clients. That way, you’ll be able to better understand how tight the cuff feels for them based on feedback.
3. Start With a Low Intensity
The best approach with people new to BFRT is to start with low-intensity activities that would barely challenge your client under normal circumstances.
Even if you’re working with a 300-lb squatter, start with nothing more than bodyweight squats so your client can get accustomed to the sensation and fatigue.
Increase the resistance if your client consistently does 30+ reps, even with shorter rest intervals.
Speaking of that:
4. Do High Reps With Shorter Rest Intervals
Blood flow restriction training is not meant to be intense. The whole point is to leverage incredibly light weights to push the muscles as if lifting heavy loads close to muscle failure.
Trainees should generally aim for 15 to 30 reps per set. I recommend prescribing a weight your clients can lift for up to 30 reps on the first set. BFRT-induced muscle fatigue piles up fast, and performance drops from set to set.
The high muscle fatigue combined with short rest intervals (around 60 seconds) means your client will do fewer reps on each subsequent set before hitting failure. Starting with 30 or so reps on the first set means they will likely drop to 12-15 reps by the last one.
FAQ
1. Is blood flow restriction training safe?
Blood flow restriction training is suggested to be safe, well-tolerated, and with no significant side effects. However, people with cardiac or blood clotting conditions should consult with a doctor before doing BFR.
2. What are the side effects of blood flow restriction?
Two potential side effects of blood flow restriction include temporary bruising and more significant muscle soreness. Tightening a cuff around the limb is also somewhat uncomfortable.
3. Do you need a certification to carry out blood flow restriction training?
Coaches and personal trainers don’t need a special certification beyond the one they have to coach blood flow restriction training. That said, various platforms offer courses on BFR for trainers looking to gain in-depth insight into the safety, effectiveness, and practical application of the method.
