title: Effects of low-intensity bench press training with restricted arm muscle blood flow on chest muscle hypertrophy: a pilot study.
abstract: Single-joint resistance training with blood flow restriction (BFR) results in significant increases in arm or leg muscle size and single-joint strength. However, the effect of multijoint BFR training on both blood flow restricted limb and non-restricted trunk muscles remain poorly understood. To examine the impact of BFR bench press training on hypertrophic response to non-restricted (chest) and restricted (upper-arm) muscles and multi-joint strength, 10 young men were randomly divided into either BFR training (BFR-T) or non-BFR training (CON-T) groups. They performed 30% of one repetition maximal (1-RM) bench press exercise (four sets, total 75 reps) twice daily, 6 days week(-1) for 2 weeks. During the exercise session, subjects in the BFR-T group placed elastic cuffs proximally on both arms, with incremental increases in external compression starting at 100 mmHg and ending at 160 mmHg. Before and after the training, triceps brachii and pectoralis major muscle thickness (MTH), bench press 1-RM and serum anabolic hormones were measured. Two weeks of training led to a significant increase (P<0.05) in 1-RM bench press strength in BFR-T (6%) but not in CON-T (-2%). Triceps and pectoralis major MTH increased 8% and 16% (P<0.01), respectively, in BFR-T, but not in CON-T (-1% and 2%, respectively). There were no changes in baseline concentrations of anabolic hormones in either group. These results suggest that BFR bench press training leads to significant increases in muscle size for upper arm and chest muscles and 1-RM strength.
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yasuda
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujita
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
authors.forename: Riki
authors.initials: R
authors.lastname: Ogasawara
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D006801:Humans; D006984:Hypertrophy; D007564:Japan; D008279:Magnetic Resonance Imaging; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000473:pathology* / Q000503:physiopathology; D010369:Pectoralis Muscles / Q000098:blood supply* / Q000473:pathology* / Q000503:physiopathology; D010865:Pilot Projects; D012039:Regional Blood Flow; D055070:Resistance Training; D013997:Time Factors; D014111:Tourniquets; D034941:Upper Extremity; D055815:Young Adult
chemical_list: D015415:Biomarkers