Effects of Resistance Training With or Without Blood Flow Restriction on Bone Metabolism in Osteopenic Women: A Randomized Controlled Trial

Background and Aims: Osteopenia in postmenopausal women increases the risk of fractures and functional decline. Exercise is a key nonpharmacological strategy to improve bone health. However, high‐intensity resistance training (HI) may not be feasible for all individuals. This study aimed to analyze the effects of low‐intensity resistance exercise with blood flow restriction (LI + BFR) compared to HI on bone metabolism in women with osteopenia. Methods: Physically inactive women (65.95 ± 8.42 years) were randomized into two groups and completed 8 weeks of intervention twice a week using a single LI + BFR or HI. Muscle strength and plasma concentrations of C‐terminal crosslinking telopeptide of type I collagen (CTX‐1), bone alkaline phosphatase (BAP), and osteocalcin (OC) were evaluated in the pre‐ and posttest. Results: Both groups showed significant gains in maximal strength (HI: ES = 2.18; LI + BFR: ES = 1.70; p < 0.05), with no between‐group differences. CTX‐1 concentrations increased significantly in both groups (HI: ES = 0.59; LI + BFR: ES = 1.13; p < 0.05), with no significant intergroup difference. No significant changes were observed in BAP or OC concentrations ( p > 0.05). Conclusions: LI + BFR and HI effectively increased maximal dynamic strength in postmenopausal women with osteopenia over an eight‐week intervention period. Both HI and LI + BFR increased CTX‐I concentrations after 8 weeks of intervention. Trial Registration: Brazilian Registry of Clinical Trials—ReBEC: RBR‐4W8V93