目的:在四组BFR自愿失败(BFR-F)或BFR(1×30,3×15,BFR-75)共重复75次之后,与运动诱发的肌肉损伤(EIMD)的患病率和程度有关的证据相互矛盾。这项调查的目的是检查肌肉肿胀,峰值扭矩,以及BFR-75和BFR-F后的神经肌肉反应方法:使用BFR-75和BFR-F方案,十三名未经训练的妇女以其最大自愿等距收缩(MVIC)的30%完成了单侧等速运动(120°s-1)腿伸展同心偏心,相隔15分钟。超声用于评估肌肉厚度,横截面积,股直肌和股外侧肌的回声强度,0-,24-,48-,72-,运动后96小时。之前,在MVIC期间记录峰值扭矩和表面肌电图(sEMG),24-,48-,72-,运动后96小时来确定sEMG振幅,频率,和神经肌肉效率。结果:条件之间无差异。在不同条件下崩溃,股直肌的肌肉厚度和横截面积在0小时时增加(2.5±0.4,2.8±0.4厘米,分别为10.6±1.8、12.1±1.8cm2)和股外侧肌(分别为2.1±0.5、2.5±0.7cm;22.2±3.9、25.1±4.5cm2),但在24小时恢复到基线。回声强度没有变化,sEMG振幅,sEMG频率,或神经肌肉效率。MVIC峰值扭矩相对于24-运动前增加,48-,72-,和96小时(159.9±34.9,171.4±30.1-179.1±35.6Nm)。结论:这些结果表明,BFR-75和BFR-F不会引起EIMD,但会引起肌肉肿胀的急性增加,并在运动后24小时恢复到基线。
Purpose: There is conflicting evidence related to the prevalence and magnitude of exercise-induced muscle damage (EIMD) following four sets to volitional failure with BFR (BFR-F) or 75 total repetitions with BFR (1 × 30, 3 × 15, BFR-75). The purpose of this investigation was to examine muscle swelling, peak torque, and neuromuscular responses following BFR-75 and BFR-F. Methods: Thirteen untrained women completed unilateral isokinetic (120°s-1) leg extensions concentric-eccentric at 30% of their maximal voluntary isometric contraction (MVIC) using BFR-75 and BFR-F protocols, separated by 15 minutes. Ultrasound was used to assess muscle thickness, cross sectional area, and echo intensity of the rectus femoris and vastus lateralis before, 0-, 24-, 48-, 72-, and 96-hours post-exercise. Peak torque and surface electromyography (sEMG) were recorded during MVICs before, 24-, 48-, 72-, and 96-hours post-exercise to determine sEMG amplitude, frequency, and neuromuscular efficiency. Results: There were no differences between conditions. Collapsed across conditions, muscle thickness and cross-sectional area increased at 0-hours for the rectus femoris (2.5 ± 0.4, 2.8 ± 0.4 cm, 10.6 ± 1.8, 12.1 ± 1.8 cm2, respectively) and vastus lateralis (2.1 ± 0.5, 2.5 ± 0.7 cm; 22.2 ± 3.9, 25.1 ± 4.5 cm2, respectively), but returned to baseline at 24-hours. There were no changes in echo intensity, sEMG amplitude, sEMG frequency, or neuromuscular efficiency. MVIC peak torque increased relative to pre-exercise at 24-, 48-, 72-, and 96-hours (159.9 ± 34.9, 171.4 ± 30.1-179.1 ± 35.6 Nm). Conclusion: These results suggest that BFR-75 and BFR-F did not cause EIMD but caused an acute increase in muscle swelling that returned to baseline 24-hours post-exercise.