title: Effects of Electrostimulation with Blood Flow Restriction on Muscle Size and Strength.
abstract: OBJECTIVE
  Low-load voluntary exercise can induce muscle hypertrophy and strength gain in working muscles when combined with blood flow restriction (BFR). However, it is unknown whether such hypertrophy and strength gain can be induced by involuntary muscle contractions triggered via low-intensity neuromuscular electrical stimulation (NMES) combined with BFR. The purpose of this article was to investigate whether low-intensity NMES combined with BFR (NMES-BFR) could elicit muscle hypertrophy and strength gain in the quadriceps.
  
  
  METHODS
  Eight untrained young male participants (mean ± SE; age, 26.2 ± 0.7 yr; height, 1.74 ± 0.02 m; body weight, 71.4 ± 4.8 kg) were subjected to 23 min of unilateral low-intensity (5%-10% of maximal voluntary contraction) NMES twice per day (5 d·wk⁻¹) for 2 wk: one leg received NMES-BFR and the other leg received NMES alone. Quadriceps muscle thickness and isometric and isokinetic strength were measured before and every week throughout the training and detraining periods.
  
  
  RESULTS
  In NMES-BFR legs, muscle thickness increased after 2 wk of training (+3.9%) and decreased after 2 wk of detraining (-3.0%). NMES-BFR training also increased maximal knee extension strength in isometric (+14.2%) and isokinetic (+7.0% at 90°·s⁻¹ and +8.3% at 180°·s⁻¹) voluntary contractions. In addition, maximal isometric strength decreased (-6.8%), whereas no large fall (-1.9% at 90°·s⁻¹ and -0.6% at 180°·s⁻¹) in isokinetic maximal strength was evident after 2 wk of detraining. In legs that received NMES alone, no prominent change was observed; there was a negligible effect on isometric strength.
  
  
  CONCLUSIONS
  Low-intensity NMES-BFR induces muscle hypertrophy and strength gain in untrained young male participants.
authors.affiliation: 1Graduate School of Health and Sports Science, Juntendo University, Inzai, JAPAN; 2Graduate School of Medicine, Juntendo University, Tokyo, JAPAN; 3Japan Society for the Promotion of Science, Tokyo, JAPAN; 4Division of Radiation Oncology, Department of Radiology, Juntendo University School of Medicine, Tokyo, JAPAN; and 5National Institute of Fitness and Sports in Kanoya, Kanoya, Kagoshima, JAPAN.
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Natsume
authors.forename: Hayao
authors.initials: H
authors.lastname: Ozaki
authors.forename: Anneyuko I
authors.initials: AI
authors.lastname: Saito
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.forename: Hisashi
authors.initials: H
authors.lastname: Naito
mesh_terms: D000328:Adult; D004558:Electric Stimulation; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D052097:Quadriceps Muscle / Q000033:anatomy & histology* / Q000098:blood supply / Q000502:physiology*; D012039:Regional Blood Flow