Low-load blood flow restriction (BFR) training promotes muscular adaptations, which can increase muscle mass and strength comparable to gains associated with high-load training programmes.
What are the results of BFR training?Following BFR training there is an increase in muscle mass, which coincides with an increase in strength. Therefore, more muscle = more lifting power. The improvement in muscle strength depends on the limb that is exposed to BFR, usually the arm or the leg – sometimes both! BFR has potential to increase both dynamic and isometric (static) strength. Results from published research: • ↑ 1RM (as much as 30%) • ↑ muscular strength (as much as 23%) • ↑ angular velocity (as much as 13%) • ↑ MVC strength (as much as 26%)
How does BFR improve strength?Training with BFR induces a number of muscular adaptations: 1. BFR alters neuromuscular function – the contracting capacity of muscle. Application of a tourniquet/cuff creates a hypoxic environment (less oxygen delivered to the muscles). This causes metabolic stress to the muscle. The result: fatigability of muscle fibres (wear the muscle out). Fatiguing muscle fibres results in progressive recruitment of motor units. Motor units are the nerve signals that recruit and contract muscles.
More motor units recruited = contract more muscle fibres = improvements in strength.2. BFR promotes an increase in muscle protein synthesis (MPS) – the driving force for building muscle. By activating cellular pathway within muscle cells this stimulates the cell to produce more protein.
More protein = more gains in muscle mass and strength.3. BFR training increases growth hormone (GH) - by as much as 290 times the resting level! Circulating GH stimulates another factor called Insulin-like growth factor 1 (IGF-1) within the muscle, which then acts on the muscle itself to promote growth.
More GH = more muscle cell growth = more muscle mass/strength.