Blood flow restriction training (BFRT) is becoming more widely used in rehabilitation and strength and conditioning environments worldwide. When used appropriately, it can be beneficial for both the general population as well as for athletes.
The following is a guest blog by Alice Brown, physiotherapist at Zone 34 and Netball NSW pathway.
WHAT IS IT?
BFRT uses a cuff to provide compression to a limb while exercising (for example, placed around the upper arm or upper thigh).
The cuff is inflated to partially limit the amount of blood leaving the muscles being worked.
The blood pooling in the limbs raises lactate levels within the muscle during training, stimulating an increase in growth hormones in the muscle at a chemical level.
WHY DO IT?
BFRT allows individuals to work under less load but achieve similar physiological benefits as when performing a similar exercise with higher resistance or weight. This is ideal for individuals when a injury or pain limits strength training exercises.
Recent studies have found that BFRT can:
- Increase strength and muscle size with only 30% of the typical load required
- Improve muscular endurance
HOW DOES IT WORK?
- Systemic and localised hormone production: metabolic by-product (such as lactate) is increased when using BFRT. Studies have found that this results in increased stimulation of growth hormones both locally within the muscles and systemically in the body – up to 170% higher than levels post traditional resistance training! It is thought that this process contributes to increases in muscle cross-sectional area
- Increased muscle protein synthesis: BFRT has a positive effect on proteins that are related to muscle hypertrophy (such as insulin-like growth factor-1). A large increase in protein synthesis with little muscle damage using BFRT means the body is primed to begin building muscle tissue.
- Higher recruitment of fast twitch muscle fibres: during regular exercise conditions, the body recruits slow twitch fibres first, then fast twitch fibres as intensity builds. Under ischemic conditions created using BFRT, fast twitch fibres are recruited from a low intensity. These fibres are important in development of strength and power
- Cellular swelling: resistance training causes cells to expand and fill with nutrients and fluid, which acts as a signal to stimulate muscle growth. This effect is magnified when using BFRT by increasing the amount of time that the muscle cells remain swollen
Before starting BFRT please arrange a telehealth or face to face consult to ensure BFRT is right for you.
What is the recommended dosage?
Use of BFRT should be tailored to an individualised program by a professional who will consider presence of pathology and any current limitations to exercise. As such, dosage can differ between each case. Broad recommendations include:
- Apply cuff and inflate pressure to 150-200mmHg, or to a VAS discomfort of 7/10
- Set 1: 30 reps
- Set 2-4: 12-15 reps
- Tempo of 1-2 seconds for both eccentric and concentric phases
- Rest for 30-60 seconds minute between sets
- If using weights, work at 20-40% 1 RM
- Deflate the cuff between exercises to allow for reperfusion
- Complete program 2-3x per week for the best benefits
Precautions
BFRT has been shown to be a safe modality, but contraindications and precautions include (though not limited to):
- Poor circulatory system
- Obesity
- Diabetes
- Arterial calcification
- Severe hypertension
- Renal compromise
- Venous thromboembolism
- Peripheral vascular compromise
- Infection in the extremities
- Previous lymph node removal
- Cancer or tumour
- Medication known to increase clotting risk
