Muscular adaptations to fatiguing exercise with and without blood flow restriction

• Published in: Clinical physiology and functional imaging Vol. 35; no. 3; pp. 167 - 176
• Main Authors: Fahs, Christopher A., Loenneke, Jeremy P., Thiebaud, Robert S., Rossow, Lindy M., Kim, Daeyeol, Abe, Takashi, Beck, Travis W., Feeback, Daniel L., Bemben, Debra A., Bemben, Michael G.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.05.2015; Wiley Subscription Services, Inc
• Subjects: Adaptation, Physiological; Adult; Female; Humans; low-load; Male; Middle Aged; Muscle Contraction; muscle endurance; Muscle Fatigue; muscle hypertrophy; muscle power; Muscle Strength; Organ Size; Quadriceps Muscle - blood supply; Quadriceps Muscle - diagnostic imaging; Quadriceps Muscle - physiology; Regional Blood Flow; Resistance Training; Time Factors; Ultrasonography; Volition; muscle strength; muscle hypertrophy; muscle endurance; muscle power; low-load
• ISSN: 1475-0961; 1475-097X; 1475-097X
• DOI: 10.1111/cpf.12141

Summary The purpose of this study was to determine the muscular adaptations to low‐load resistance training performed to fatigue with and without blood flow restriction (BFR). Middle‐aged (42–62 years) men (n = 12) and women (n = 6) completed 18 sessions of unilateral knee extensor resistance training to volitional fatigue over 6 weeks. One limb trained under BFR, and the contralateral limb trained without BFR [free flow (FF)]. Before and after the training, measures of anterior and lateral quadriceps muscle thickness (MTh), strength, power and endurance were assessed on each limb. The total exercise training volume was significantly greater for the FF limb compared with the BFR limb (P<0·001). Anterior quadriceps thickness and muscle function increased following the training in each limb with no differences between limbs. Lateral quadriceps MTh increased significantly more (P<0·05) in the limb trained under BFR (BFR: 3·50 ± 0·61 to 3·67 ± 0·62 cm; FF: 3·49 ± 0·73 to 3·56 ± 0·70 cm). Low‐load resistance training to volitional fatigue both with and without BFR is viable options for improving muscle function in middle‐aged individuals. However, BFR enhanced the hypertrophic effect of low‐load training and reduced the volume of exercise needed to elicit increases in muscle function.