Blood flow restriction (BFR) training

Blood flow restriction (BFR) training applies a pneumatic cuff or elastic wrap proximally to a limb to partially occlude venous return while preserving arterial inflow, enabling low-load exercise — typically 20–40% of one-repetition maximum (1RM) — to produce skeletal-muscle hypertrophy and strength gains comparable to conventional high-load training at 70–85% 1RM. The resulting distal blood pooling creates an acute hypoxic, metabolically stressful environment that recruits higher-threshold fast-twitch motor units earlier than load alone would demand, amplifies growth hormone and IGF-1 release, promotes cellular swelling, elevates intramuscular inorganic phosphate, and activates mTORC1-mediated protein synthesis — mechanisms reviewed by Pearson and Hussain (2015). For older adults in whom heavy loading is contraindicated due to joint pathology, osteoarthritis, or post-surgical rehabilitation, BFR offers a pathway to preserve or rebuild muscle mass without imposing high mechanical stress on tendons and cartilage. A 2019 systematic review and meta-analysis by Centner et al. found statistically significant increases in muscle cross-sectional area and strength in individuals over 60, though effect sizes were generally smaller than in younger cohorts. A 2022 systematic review and meta-analysis by Cahalin et al. concluded that BFR is effective in older adults with or at risk of sarcopenia, while noting that optimal cuff pressure, exercise volume, and session frequency remain incompletely standardised across trials.