Hypertrophic effects of low-load blood flow restriction training with different repetition schemes: a systematic review and meta-analysis

Objective This systematic review and meta-analysis analyzed the effect of low-load resistance training (LL-RT) with blood flow restriction (BFR) versus high-load resistance training (HL-RT) on muscle hypertrophy focusing on the repetition scheme adopted. Methods Four databases were searched to identify randomized controlled trials that compared the effect of LL-RT with BFR versus HL-RT on muscle hypertrophy. Standardized mean differences (SMD) were pooled in a random effects meta-analysis. Results The overall analysis did not demonstrate significant differences between conditions (SMD = 0.046; p=0.14). A similar result was observed when we separately analyzed studies that used sets to momentary muscle failure (SMD = 0.033; p=0.520), sets of 15 repetitions (SMD = 0.005; p=0.937) and a fixed repetition scheme composed of 75 repetitions (SMD = 0.088; p=0.177). The analysis considering body region indicates no difference in lower limb exercise between HL-RT and LL-RT with BFR (SMD = 0.00066; p=0.795) while upper limb exercise favors HL-RT (SMD = 0.231; p=0.005). Conclusion LL-RT with BFR elicits muscle hypertrophy similar to HL-RT regardless of the employed repetition scheme, although there appears to be a small beneficial effect in favor of HL-RT in upper limb exercise.