title: Combining normobaric hypoxia with short-term resistance training has no additive beneficial effect on muscular performance and body composition.
abstract: The aim of this study was to determine the effects of short-term resistance training combined with systemic hypoxia on muscular performance and body composition. Eighteen resistance-untrained men (21.3 ± 2.0 years, 172.7 ± 5.5 cm, 67.3 ± 9.7 kg) were matched and assigned to 2 experimental groups: performing 6 weeks of squat exercise training under normobaric hypoxia (H, FiO2 = 15%) or normoxia (N). In both groups, subjects performed 3 weekly sessions (a total of 18 sessions) of 3 sets of back squat at 10-repetition maximum with 2 minutes of rest between sets. Dynamic, isometric, and isokinetic leg strength and body composition were measured under normoxia before and after resistance training. Squat 1 repetition maximum (1RM) improved significantly (p ≤ 0.05) after resistance training in both H and N groups (88.9 ± 16.9 to 109.4 ± 17.0 kg and 90.0 ± 12.2 to 105.6 ± 13.3 kg, respectively). However, there were no changes in maximal isometric and isokinetic leg strength, lean body mass, and fat mass after the resistance training in both groups. In addition, no significant differences were observed between H and N groups in squat 1RM, maximal isometric and isokinetic leg strength, and body composition. The major findings of this study suggest that short-term resistance training performed under normobaric hypoxia has no additive beneficial effect on muscular performance and body composition. In practical terms, our data suggest that the use of systemic hypoxia during short-term resistance training is not a viable method to further enhance muscular performance and body composition in previously resistance-untrained men.
authors.affiliation: Departments of 1Athletic Performance; and 2Physical Education, National Taiwan Normal University, Taipei, Taiwan.
authors.forename: Jen-Yu
authors.initials: JY
authors.lastname: Ho
authors.forename: Tai-Yu
authors.initials: TY
authors.lastname: Kuo
authors.forename: Kuan-Lin
authors.initials: KL
authors.lastname: Liu
authors.forename: Xiang-Yi
authors.initials: XY
authors.lastname: Dong
authors.forename: Kang
authors.initials: K
authors.lastname: Tung
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D054874:Athletic Performance; D001823:Body Composition; D003430:Cross-Sectional Studies; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance; D012016:Reference Values; D055070:Resistance Training / Q000379:methods*; D055815:Young Adult