title: Effect of low-load resistance exercise with and without blood flow restriction to volitional fatigue on muscle swelling.
abstract: OBJECTIVE
  The effects on muscle swelling were compared between low-load resistance exercise to exhaustion with (BFR) and without blood flow restriction (NBFR).
  
  
  METHODS
  Ten young men [aged 27 (SD 5) years, standing height 1.74 (SD 0.05) m, body mass 70.3 (SD 4.3) kg] performed 20 % of one repetition maximal dumbbell curl exercise to exhaustion (four sets, rest intervals were 30 s for BFR and/or 3 min for NBFR, respectively). One arm was randomly chosen for BFR exercise and the other arm performed NBFR exercise. During the BFR exercise session, an elastic cuff was worn proximally on the testing arm at 160 mmHg. Electromyography (EMG) signals were recorded from surface electrodes placed on the biceps brachii muscle and analyzed for integrated EMG (iEMG). Biceps brachii muscle thickness (MTH) was measured using B-mode ultrasound.
  
  
  RESULTS
  The total number of exercise repetitions was greater (p < 0.01) in NBFR (221 ± 67 reps) than in BFR (111 ± 36 reps). During the exercise session, iEMG for biceps brachii muscles increased (p < 0.01) during BFR and NBFR (3.94 and 4.45 times of baseline value). Immediately after the exercise, MTH sharply increased (p < 0.01) with BFR and NBFR (1.21 and 1.20 times of baseline value). These results demonstrate that both BFR and NBFR exercises lead to pronounced muscle activation and muscle swelling.
  
  
  CONCLUSIONS
  Low-load resistance exercise to exhaustion is an effective method for promoting muscle swelling regardless of BFR. Furthermore, our data indicate that the increase in muscle swelling for both NBFR and BFR is maintained even 60 min after the exercise.
authors.affiliation: Department of Ischemic Circulatory Physiology, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan, yasuda-tomohiro@umin.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yasuda
authors.forename: Kazuya
authors.initials: K
authors.lastname: Fukumura
authors.forename: Haruko
authors.initials: H
authors.lastname: Iida
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D000328:Adult; D001132:Arm / Q000098:blood supply; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D055815:Young Adult