title: Greater gains in strength and power with intraset rest intervals in hypertrophic training.
abstract: We sought to determine if hypertrophic training with intraset rest intervals (ISRs) produced greater gains in power compared with traditional rest (TRD) hypertrophic training. Twenty-two men (age 25 ± 5 years, height 179.71 ± 5.04 cm, weight 82.1 ± 10.6 kg, 6.5 ± 4.5 years of training) matched according to baseline characteristics were assigned to 12 weeks of training using TRD or ISR. Body composition, strength (1-repetition maximum [1RM] bench and squat), and power output (60% 1RM bench and squat, and vertical jump) were assessed at baseline, 4, 8, and 12 weeks. Determination of myosin heavy chain (MHC) percentage from the vastus lateralis was performed pretraining and posttraining. Body composition was analyzed by analysis of variance, whereas performance measures and MHC were analyzed by analysis of covariance with baseline values as the covariate. Data are presented as mean ± SD changes pre to post. The ISR produced greater power output in bench (TRD 32.8 ± 53.4 W; ISR 83.0 ± 49.9 W, p = 0.020) and vertical jump (TRD 91.6 ± 59.8 W; ISR 147.7 ± 52.0 W; p = 0.036) with squat power approaching significance (TRD 204.9 ± 70.2 W; ISR 282.1 ± 104.2 W; p = 0.053) after post hoc analysis (p < 0.10). The ISR produced greater gains in bench (TRD 9.1 ± 3.7 kg; ISR 15.1 ± 8.3 kg; p = 0.010) and squat (TRD 48.5 ± 17.4 kg; ISR 63.8 ± 12.0 kg; p = 0.002) strength. Both protocols produced significant gains in lean mass with no significant differences between groups (1.6 ± 2.1 kg; p = 0.869). The MHCIIx percentage decreased (-31.0 ± 24.5%; p = 0.001), whereas the MHCIIA percentage increased (28.9 ± 28.5%; p = 0.001) with no significant differences between groups. Results indicate that hypertrophy training with ISR produces greater gains in strength and power, with similar gains in lean mass and MHC alterations as TRD. The ISR may be best used in hypertrophic training for strength and power sports.
authors.affiliation: 1Department of Health and Kinesiology, Texas A&M University, College Station, Texas; 2Department of Kinesiology, Texas Christian University, Fort Worth, Texas; 3Texas A&M Naval ROTC Unit, Texas A&M University, College Station, Texas; 4Walter Reed National Military Medical Center, Bethesda, Maryland; 5Department of Systems Biology and Translational Medicine, Texas A&M University Health Science Center, College Station, Texas; and 62d Maintenance Battalion, United States Marine Corps, Camp Lejeune, North Carolina.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Oliver
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Jagim
authors.forename: Adam C
authors.initials: AC
authors.lastname: Sanchez
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Mardock
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Kelly
authors.forename: Holly J
authors.initials: HJ
authors.lastname: Meredith
authors.forename: Gerald L
authors.initials: GL
authors.lastname: Smith
authors.forename: Mike
authors.initials: M
authors.lastname: Greenwood
authors.forename: Janet L
authors.initials: JL
authors.lastname: Parker
authors.forename: Steven E
authors.initials: SE
authors.lastname: Riechman
authors.forename: James D
authors.initials: JD
authors.lastname: Fluckey
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Crouse
authors.forename: Richard B
authors.initials: RB
authors.lastname: Kreider
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology; D001823:Body Composition; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D052097:Quadriceps Muscle / Q000378:metabolism; D055070:Resistance Training / Q000379:methods*; D012146:Rest / Q000502:physiology*; D055815:Young Adult
chemical_list: D018995:Myosin Heavy Chains