It might sound counterintuitive to restrict the blood supply in and out of your muscles when you exercise, but it’s an extremely effective way to alter the training effect and build strength and muscle size.
As the name suggests blood flow restriction (occlusion or Kaatsu) training involves wrapping a specially designed tourniquet cuff at the top of the arms or legs when training to safely restrict some of the blood flow in and out of your limbs. This alters the chemical balance in your muscles while you workout and triggers an increase in muscle size and strength.
As a Physiotherapist who specialises in post-operative orthopaedic rehab, I find BFR to be an invaluable tool in rehabilitation because gentler (lower intensity) exercises can be made to feel like heavier, more challenging exercises. Essentially, my patients can achieve the benefits of a more intense strength training session while still protecting the structures which are healing.
How does Blood Flow Restriction Training work?
Changing the blood blow in and out of muscles during a workout forces your muscles to work a bit harder and as a result they produce more lactate. This is a type of energy or fuel produced by your muscles when you exercise but there isn’t quite enough oxygen to meet the demand.
Increases lactate production creates a more demanding environment in your cells (metabolic stress) and stimulates a number of amazing changes which results in the changes you see in muscle size (hypertrophy) and strength including:
- Release of growth hormone
- Activation of more muscle fibres
- Growth of new blood vessels
- Adaptations in your cells (the mitochondria), so they produce energy more efficiently
- Widening of blood vessels (vasodilation) after exercising to improve recovery
Is blood flow restriction training safe?
BFR training is safe when it’s performed correctly and you follow the recommended guidelines. There are some conditions that mean blood flow restriction training would not be recommended, so I always recommend discussing this approach with a medical professional beforehand. They should screen to check if it’s an appropriate training technique for you and teach you how to do it safely.
Benefits of using BFR
To build muscle you normally have to lift about 70-80% of your maximum ability (1RM) but with a BFR workout, you only need to use 20-30% of your max to get the same results. So it really benefits people who are recovering from surgery (particularly in ACL rehab) or who might struggle to lift heavier weights due to injury or joint limitations. I also use it with patients who need a ‘joint friendly ‘approach to training like those with hypermobility or osteoarthritis.
So it’s perfect for rehabilitation. It’s also really time efficient since BFR training really maximises the activity in your muscles, so you get a more intense workout in a shorter amount of time. This makes it ideal for those with busy schedules or anyone looking for a more efficient way to train.
BFR mainly has an effect on the muscles of the limbs that the bands are placed on, but you will also get the benefits from the strength training in your torso as well as you lift.
Ready to get started with BFR training?
First of all you need to ask your physiotherapist or health care provider to complete a health screening questionnaire.
Once they are satisfied that it’s a safe training technique for you, the next step is choosing the right equipment. In my practice I use BFR bands which auto-calibrate so I know exactly how much pressure is being applied and can adjust them quickly and easily to the correct fit. Once applied BRF cuffs should be tight but not painful and you should be able to move in them easily. Your Physio should be able to teach you the correct placement.
When using BRF cuffs, you should train with lower weights than usual (20-30% of your max ability), complete high numbers of repetitions with a short break between sets. Start with simple compound exercises like squats, deadlifts, shoulder press or bench press. Make sure to remove the bands between sets and stop immediately if you experience any pain, dizziness or numbness.
Starting slowly and building things up carefully will give you safe, effective results … and don’t hesitate to get in touch if you have any questions or would like to learn how to do this with me!
Blog post written by Mateo Castaño Giraldo. A Chartered Physiotherapist specialising in post-operative rehab and Sports Injury Care. As an ex-pro footballer, Mateo enjoys helping his patients get back to their sports – particularly team running sports – safely and quickly.
