Immediate Effects of High-Intensity Blood Flow Restriction Training on Muscle Performance and Muscle Soreness

<b>Purpose:</b> The aim was to investigate the immediate effects of high-intensity resistance training with blood flow restriction (HIRT-BFR) on rectus femoris (RF) muscle activity, reaction time, muscular performance, and delayed onset muscle soreness (DOMS) in healthy young adults. <b>Methods:</b> Twenty-four healthy young adults were randomized into the HIRT-BFR group or HIRT group. Both groups performed a single session of training with 80% of 1RM, 8 repetitions, 2 sets, and 3 minutes rest to RF muscle. The activity and reaction time of the dominant extremity RF muscle were evaluated by superficial electromyography (sEMG), muscular performance by single-leg squat test, and DOMS by the Visual Analog Scale. <b>Results:</b> Single-leg squat performance was significantly increased in HIRT-BFR (<i>p</i> = .001) and HIRT group (<i>p</i> = .04). Additionally, in HIRT group resting average (<i>p</i> = .03), resting maximal voluntary contraction % (<i>p</i> = .04), and relaxation minimum (<i>p</i> = .02) values of RF were significantly increased. DOMS level decreased significantly in HIRT-BFR (<i>p</i> < .001) and HIRT group (<i>p</i> = .019). The differences were similar in the groups for sEMG parameters, muscle performance, and DOMS level. <b>Conclusion:</b> We observed that HIRT-BFR and HIRT were similar in terms of muscle activation, reaction time, muscular performance of the RF, and DOMS level.Trial registration number: This study is registered at www.clinicaltrails.gov (NCT05274542).