Effects of blood flow restriction exercises on bone metabolism: a systematic review.

This study analysed the effect of low-intensity (LI) exercises with blood flow restriction (BFR) on bone metabolism compared with high-intensity (HI) exercises without BFR. The following databases were searched using the keywords therapeutic occlusion training OR BFR training OR vascular occlusion training OR KAATSU training OR ischaemia training AND osteogenesis OR bone biomarkers OR bone metabolic marker OR bone mass OR bone turnover OR osteoporosis OR osteopenia: PubMed, Web of Science, SPORTDiscus, CINAHL, Science Direct, Cochrane and Google Scholar. Two researchers, independently and blindly, selected the studies based on established inclusion and exclusion criteria. Electronic and manual searches located 170 articles published in English; after screening, only four studies showed that BFR training increases the expression of bone formation markers (e.g. bone-specific alkaline phosphatase) and decreases bone resorption markers (e.g. the amino-terminal telopeptides of type I collagen) after both aerobic and anaerobic exercise across several populations. The results of this study show that few studies have confirmed the positive effect of exercise with BFR on bone metabolism, formation and resorption. Furthermore, no methodological standardization of the samples, exercise type, intervention frequency or duration was observed.

Effects of strength training with blood flow restriction on torque, muscle activation and local muscular endurance in healthy subjects.

The present study aimed to analyse the effects of six weeks of strength training (ST), with and without blood flow restriction (BFR), on torque, muscle activation, and local muscular endurance (LME) of the knee extensors. Thirty-seven healthy young individuals were divided into four groups: high intensity (HI), low intensity with BFR (LI+BFR), high intensity and low intensity + BFR (COMB), and low intensity (LI). Torque, muscle activation and LME were evaluated before the test and at the 2nd, 4th and 6th weeks after exercise. All groups had increased torque, muscle activation and LME (p<0.05) after the intervention, but the effect size and magnitude were greater in the HI, LI+BFR and COMB groups. In conclusion, the groups with BFR (LI+BFR and COMB) produced magnitudes of muscle activation, torque and LME similar to those of the HI group.