Systematic Review on the Mid- To Long-Term Effects and Safety of Blood Flow Restriction Therapy

Introduction High Intensity Resistance Training (HIRT) is the gold standard for muscle training, but high loads pose a risk to the vulnerable groups, such as the elderly or those who have undergone surgery. Blood flow restriction therapy (BFRT) has been posed as an alternative, which involves conducting Low Intensity Resistance Training (LIRT) with a tourniquet on the limb/ limbs, allowing for equivalent muscle adaptations under lower intensities of exercise. This review aims to address the gap in the mid to long term effects of BFRT in the literature. Method A literature search was conducted throughout the period of August 2023. 12 randomised controlled trials (RCTs) were selected for the review after exclusion. These included contributions from Japan, North America, Germany and Brazil. Studies included 221 healthy participants at average age of 24 with minim training period of eight weeks. The outcomes assessed were strength, hypertrophy endurance performance and safety. Results BFRT consistently improved strength and hypertrophy compared to baseline LIRT. Gains were generally comparable to HIRT. Endurance outcomes, like VO2max, were also comparable to HIRT. BFRT was well tolerated, with no increased perceived exertion or pain and no reported complications. Discussion BFRT's benefits stem from inducing a hypoxic environment, mimicking HIRT's mechanism of action. This involves increased growth hormone release, anabolic signalling, anaerobic metabolic accumulation and preferential type II muscle recruitment. This study has shown that BFRT is a safe and effective alternative to muscle development. Conclusion This review shows significant mid to long term benefits of BFRT for muscle strength, hypertrophy and endurable, comparable to HIRT, with fewer posed risks. It is a valuable tool requiring further research to standardise protocols.